Time for a Black Eye

Which Black Eyed Susan is Which? 

Harris Checkerspot butterfly on Rudbeckia hirta (Black Eyed Susan).

Do you want a black eye? Black eyed Susan, that is. Or is that a brown eyed Susan? The other day someone asked me how to differentiate this group of plants that, at first glance, look so much alike. Today, I will attempt to tackle that question here. 

Those who know me know that I get really frustrated with common names for plants. Depending on where you live, the name black eyed Susan is used for a number of different yellow flowers with a dark center. The most common ones, at least here in southern Ontario, are Rudbeckia hirta (which I call black eyed Susan), Rudbeckia triloba (brown eyed Susan) and Rudbeckia fulgida (orange coneflower). However, these plants also come with a lot of other names that you might know them by, just to keep things confusing. For example: 

Rudbeckia hirta (Black Eyed Susan) is also called Bristly Coneflower, Brown Betty, Brown-eyed Susan, Common Black-eyed Susan, English Bull’s Eye, Gloriosa Daisy, Golden Jerusalem, Poor-land Daisy, Yellow Daisy and Yellow Ox-eye Daisy. 

Rudbeckia fulgida (Orange Coneflower) is also known as Black Eyed Susan, Brilliant Coneflower, Brown Eyed Susan, Orange Rudbeckia, Perennial Black-eyed Susan, Showy Black-eyed Susan and Showy Coneflower. 

Rudbeckia triloba (Brown Eyed Susan) also goes by the names Thin-leaved Coneflower, Three-lobed Coneflower and Three-lobed Rudbeckia. 

But it’s not just the names that can be confusing. To the uninitiated, these 3 flowers look very similar. And the descriptions you read about them don’t always help, simply because there can be so much variability within each species that, until you get to know the plants, the descriptions seem to overlap. 

Rudbeckia hirta – Black Eyed Susan 

Let’s start with Rudbeckia hirta, Black Eyed Susan. For me, the main differentiating characteristic is the fuzzy leaves and stems – fuzzy enough that the leaves actually appear to be a lighter colour than the other Rudbeckias. But fuzziness is a relative characteristic as all 3 have a certain amount of hairiness to the leaves and stems. Once you see the leaves side by side, however, you will easily tell them apart in the future (most of the time).  

R. hirta leaves tend to be strap-like and, on average, tend to be longer and narrower than the other two. And they are ALMOST ALWAYS very hairy. 

This plant is quite variable in its nature, though. It may be an annual, a biennial or even a short-lived perennial in some cases. And the genetic variability within the species can result in individuals with different petal shapes, different leaf shapes and sizes, and even a range of hairiness of the stem and leaves. But on average, the leaves and stems have a pale fuzzy appearance. If it’s late in the season, they also tend to die off in early fall (at least the annual and biennial ones do) whereas R. fulgida and R. triloba tend to stay green well into the late fall, even after the flowers have finished. 

Rudbeckia hirta does well in full sun to part shade in just about any dry to moist, reasonably fertile, well-drained soil. This plant will grow to a little over 3’ tall and in the wild is found in fields, open woods and along roadsides. 

R. hirta Native Range

Rudbeckia hirta is found throughout the region, though it may be spotty or even non-existent depending on soil, microclimate and other characteristics.

Rudbeckia fulgida – Orange Coneflower 

This shorter statured plant is an extremely popular garden perennial, mainly because once it starts blooming it tends to put on a non-stop show for months. In most years in my southwestern Ontario garden, it starts to flower in late June or early July and keeps going till frost – sometimes as late as November, though after the drought we had here this year, they’ve pretty much finished blooming in mid-September. 

A very common cultivar (or nativar, if you prefer) is Goldsturm. There are also even shorter cultivars, usually with the word “Little” somewhere in the name. The straight species typically grows 2-3’ tall, as does the Goldsturm variety. Most of the others are only 1-2’ tall. I have yet to find a definitive article on how Goldsturm is different from the true species. If you have the scoop on this, please let me know. 

The leaves on R. fulgida tend to be much wider than on R. hirta and usually have fairly large serrations along the edges, especially on the lower leaves. As you can see in the photos, though, they may have no serrations at all. And though they may feel somewhat rough and hairy, they are not nearly as hairy (on average) as R. hirta. 

One thing is for sure – R. fulgida produces a much denser mass of colour than R. hirta, and for a much longer period of time, though R. hirta always starts flowering a couple of weeks before this one does. It’s not that fussy about where it grows – it will do well in moist to dry, sandy to clay soils in full sun to part shade. I have a patch that is in full, light shade and it is doing just fine.  

Rudbeckia fulgida typically provides a nice, solid mass of showy flowers in the garden.

R. fulgida Native Range

Rudbeckia fulgida is a more southerly plant, barely making it into Ontario.

Rubeckia triloba – Brown Eyed Susan 

Not native in Ontario, this nonetheless very popular short-lived (typically 2-3 years) perennial is the tallest of the 3 plants discussed here – in ideal conditions (full sun, moist loamy soil) it can get upwards of 5’ in height, though one writer indicated his plant hit 8’ tall!  

The easiest way to differentiate R. triloba from the other two is to take a look at the leaves near the base of the plant. These are what give this plant its specific epithet (or species name) – triloba. The lower leaves have 3 (occasionally 2) lobes, as seen in the accompanying photo. The upper leaves look quite similar to R. fulgida, with the same variability in hairiness and serrations.  

The other telltale difference is that R. triloba also tends to have a fairly reddish stem – sometimes it may be a deep solid burgundy colour, but on other plants it may be more of a striped stem. The stems are almost always fairly hairy.  

Rudbeckia triloba is probably the fussiest of the 3 for growing conditions, but it is still quite versatile. It prefers moist to mesic loamy or sandy-loam soils, though some clay is tolerated. Like Rudbeckia fulgida, it blooms from July to first frost. 

R. triloba Native Range

Rudbeckia triloba range matches fairly closely with R. fulgida, but historical records indicate is was not known in Ontario before Europeans arrived.

If you have a native plant gardening related topic that you would like to know more about, let me know and I will add it to my growing list (pun intended). If it’s something I get multiple requests for, or is simply something that strikes my fancy, it will surely move up the priority list. 

Happy Native Plant Gardening.  

Helianthus tuberosus – Jerusalem Artichoke

Fall is a time of food harvesting, and a few of our native plants have provided tasty nutrition for humans for hundreds if not thousands of years. One such plant is a member of the sunflower family, noted not for its sunflower seeds (of which it rarely produces any) but for its delicious roots. That plant is Helianthus tuberosus – the Jerusalem Artichoke. 

Common Name:  Jerusalem Artichoke 

Scientific Name: Helianthus tuberosus 

Family: Asteraceae (Aster Family) 

Alternate Common Names: Canada Potato, Earth-apple, Girasole, Sunchoke, Sunflower Artichoke, Sunroot, Tuberous Sunflower 

Plant description: Jerusalem Artichoke has upright, rigid stems that are light green to reddish brown in colour and are covered in stiff hairs. The stems are unbranched except for towards the top where the flowers are found. Shallowly toothed leaves occur in an opposite arrangement on the lower part of the plant and become alternate as they ascend the stem. They are up to 25cm long and 12cm wide, lance-shaped to ovate with a pointed tip, rounded base and rough texture on top. Leaves are borne on winged leaf stalks ranging from 2cm to 7.5cm long, becoming shorter as they ascend the stem. Stems terminate with flowers that measure up to 9cm wide and are characterized by 10-20 yellow ray florets (petals) surrounding a slightly darker center disk. At the base of each flower are 2-3 sets of overlapping bracts, each being 1.2cm long, hairy and pointed. Flowers become dry seed heads each containing flattened and slightly downy seeds. 

In the Garden: Jerusalem Artichoke is a very robust sunflower, putting on a dramatic display of yellow blooms in early fall. The tall, rigid stems persist throughout the winter months to extend wildlife value and garden interest. Best suited to large gardens or naturalized areas where it can be allowed to spread. 

Lifespan: perennial 

Exposure: full sun to part shade 

Soil Type: prefer loose, well-drained soil, but will tolerate poor soils.  

Moisture: moist to dry, but do not plant in areas that are consistently wet, as wet soil will rot the tubers 

Height:  300 cm 

Spread:  100 cm 

Bloom Period: Aug, Sep, Oct 

Colour: yellow 

Fragrant (Y/N):

Showy Fruit (Y/N): 

Cut Flower (Y/N):

Pests: powdery mildew 

Natural Habitat: open areas and moist thickets, prairie remnants along railroads, moist meadows along rivers, woodland borders, and is mostly found in disturbed areas 

Wildlife value: several native bees are attracted to the flowers and the seeds are an important source of food for many birds and small mammals; when growing near streams or ponds, H. tuberosa stems and leaves are used by beavers and muskrats for dam and den building 

Butterfly Larva Host Plant For: Gorgone Checkerspot (Chlosyne gorgone), Silvery Checkerspot (Chlosyne nycteis), and Painted Lady (Vanessa cardui

USDA Hardiness Zone: 3-9 

Propagation: Although possible to grow from seed, it is rarely done because this plant is so easy to grow from tubers or pieces of tubers (also, seeds tend to have low viability). Place your tubers in the ground, root-down and stalk-up, around 12.5 cm deep, and cover with soil. The best time to plant is in the spring after the danger of deep freezing has passed, but these hardy plants can be planted just about any time the ground isn’t frozen. 

Additional Info: Jerusalem artichoke has been grown commercially for use as a human food source, for livestock feed and for ethanol production. Cultivated varieties yield white tubers that are clustered near the main stem as opposed to wild types which produce reddish elongated tubers at the end of long rhizomes.  

Jerusalem artichoke is a very aggressive spreader in the garden. In my own garden, I planted them in half of a plastic 45 gallon drum, buried in the ground, to prevent spreading into my lawn. Each fall I harvest all the pieces of root I can find, and the little pieces I miss are enough to provide a full crop the next year.  

Half a large plastic barrel sunk into the ground keeps the Jerusalem Artichoke from taking over my yard.

Native Range: 

Jerusalem Artichoke on the menu: I normally don’t offer commentary on the edibility of native plants in the garden, nor instruction on preparing them as food. This is because I grow native plants for wildlife, not for my own consumption. Jerusalem artichoke is one of the exceptions.  

The tubers of Jerusalem Artichoke are said to have a nutty flavour, somewhere between a potato and artichoke hearts (having never had artichoke hearts, I can’t verify this – but they do not taste anything like potatoes, in my mind). Depending on the variety and the growing conditions, the tubers may be small, thumb-sized or less, right up to the size of your fist.

Wash the tubers well, then pretty much anything you can do with potatoes you can do with these tubers: sliced and pan fried, steamed, boiled, microwaved, added to soups, roasted or even eaten raw to add a bit of crunch in salads. Google “Jerusalem artichoke recipes” and you’ll find lots. My personal preference is roasted in the oven or wrapped in tinfoil on the BBQ – this seems to concentrate the sugars and flavour.  

According to the Food Revolution Network (https://foodrevolution.org/blog/jerusalem-artichokes/), “Jerusalem artichokes are also a good source of inulin and oligofructose, which are types of fiber that act as potent prebiotics, or food for probiotics, which are the good bacteria in your gut. Inulin is a soluble fiber that also works to balance your blood sugar.” 

However, there is a downside for those with sensitive stomachs. The inulin and oligofructose can cause gas, bloating, and even abdominal pain and diarrhea in certain people. For this reason they are also known as “fartichokes”. Cooking them well can help reduce this effect, and some say that harvesting after a good frost also helps. As with consuming any wild plants, though, if you are at all concerned be sure to do some research first and approach with caution. 

Most sources I’ve read indicate you can loosely wrap the tubers in a paper towel and store in the crisper drawer for up to two weeks. I either have an excellent crisper, or exceptional tubers: mine stayed crisp and delicious for more than 6 months left loosely bagged in an unsealed large freezer bag in the drawer. 

Happy Native Plant Gardening. 

How Does Your Garden Grow?

Many of is remember the old nursery rhyme Mary, Mary, quite contrary, How does your garden grow?

Although historians disagree on the possible political meanings behind this 18th century English nursery rhyme, I wish to use this question “How does your garden grow” to explore the various approaches to gardening with native plants.

Naturalized Gardens

We all garden with native plants for different reasons. Some gardeners attempt to create a more ‘natural’ habitat for insects, birds and other wildlife on their property and design their gardens around ecological principles. These gardens may often appear messy to the uninitiated, and are often more suited to larger properties and/or rural properties. Otherwise, they may fall afoul of local city ordinances that were often developed in the 60s and 70s when uniform, mowed grass was seen as desirable and when bylaws were enacted to prevent homeowners from simply neglecting their yards.

Formal Gardens

At the other end of the spectrum are those who have taken the formal flower beds of European ancestry and simply replaced some or all of the non-native species with native ones. These gardens are often geared to human sensibilities and historical tastes. The fact they attract more insect life than gardens comprised solely of exotic species is more a lucky side effect than a planned outcome.

And then there is the whole gamut of garden design options between the two extremes.

Semi Formal

The Importance of Native Plants

I would be willing to bet that most of us grow native plants, at least in part, for the benefit they provide to our wildlife. To that end, ANY incorporation of native species is likely to be better than none at all. However, Doug Tallamy’s research in the US has shown that the successful fledging of a nest of Carolina chickadees requires at least 70% native species within their foraging range. And anything below 30% will likely result in the complete loss of the nest of babies. This is because non-native plants do not host the diversity and numbers of insects necessary to feed a nestful of baby birds. Although Tallamy’s research looked at just the one bird species, it is probably safe to assume that it is similar for other bird species, since most birds – even the seed eaters – raise their young on a diet of caterpillars, spiders and other soft-bodied insects. (If you haven’t read them yet, I highly recommend Tallamy’s books Bringing Nature Home and Nature’s Best Hope.)

If you’re reading this article, then you are most likely already aware of the importance of native plants. But how many others are? You would hope that anyone who gardens would have an appreciation for nature. And even though native plant gardening is the fastest growing (pun intended) sector of horticulture in North America, a lot of gardeners are still unaware of its virtues.

Take for example a recent trip I made to a scenic small town in southern Ontario, noted for its active horticulture society and its beautiful gardens. In a 10 block walk, I saw one yard containing a native species in its flower beds. Note the singular. And technically, the town was a bit far north to actually claim Rudbeckia fulgida (orange coneflower) as a native species. (To be fair, in another part of town I did find a couple of gardens that were primarily natives, but that was it.) We have a long way to go to educate other gardeners on the benefits (and beauty) that adding native plants can provide.

Where Do I Start?

But if we want to grow natives, which way is best? Well, that depends. My own gardens fall somewhere closer to the ‘formal flower beds’ end of the spectrum, designed to be showcases of what we can do with native species. Though with the passage of time they are slowly moving away from that as I let plants spread and self-seed, often where they want.

I came at my gardens from the perspective of an educator wanting to show folks that native plants can be just as beautiful, and usually a lot more beneficial, than non-native species. My aim has been to bring those who knew only the Edwardian style of manicured gardens full of exotic plants into the world of native plant gardening.

In the municipality of Chatham-Kent (in southwestern Ontario) we recently held our second annual native plants garden tour. (Thanks and a shout out to Mike Smith with ReLeaf Chatham-Kent for spearheading this). This year, gardens once again ranged from restored acreages to small butterfly gardens, from gardens planted in a cul-de-sac island by a committee to a half acre of formal flower beds of only native species set in a private garden. Some have natives mixed with non-natives while other “purists” try to plant only what was found locally (or nearby) before Europeans arrived. Some have been growing natives for a decade or more; for others this is their first venture into growing indigenous species.

If you’re reading this, then at least you are interested in growing native plants. And if you haven’t started yet, don’t worry – it’s easy. But it will take some thought and some homework. First you need to decide WHY you want to grow native plants. That will help you choose the style that will work best for you.

Do you have already established garden beds? Perhaps you just bought your first house and have inherited a lot of non-native and possibly some invasive species. Do you like the layout of the gardens, or do you have a vision of your own? Start by identifying the non-natives that are invasive or otherwise problematic and digging those out. There are lots of on-line resources to help with this. Just Google “invasive plants” and your state or province. Or look up a document called “Plant me Instead”. Visit some native plant nurseries (this web site has a map of all the native plant sources in North America that I’ve been able to find), attend a webinar by your local naturalist organization, join a native plant gardening Facebook group (if you haven’t already). These are all great ways to learn about what is or isn’t native and to help you decide what to plant where.

Do you have a large, blank slate? This can sometimes be very intimidating. And unless you’ve got very deep pockets, you probably won’t want to convert the whole yard at once. But don’t just jump in with both feet. Even if you’ve been growing natives for a while, if this is a new location then watch the sun – where is it sunny the longest? Where is the shade? What is your soil type? (If you don’t know, get it tested. Your local department of Agriculture will be able to tell you where, and how much it will cost. Or you can buy a soil test kit from a number of sources, and though these won’t be quite as accurate as an official laboratory test, they may be good enough to get you started.) Is the soil dry? Are there low areas that might stay wet for part of the year or after a heavy rain? If all else fails, there are lots of knowledgeable folks living probably not far from you, and some of these will be happy to come and advise you (for a fee).

Water is Important,Too!

If your intention is to attract birds, dragonflies and other creatures, try to add moving water – either a small waterfalls or simply a fountain. The sound of running water will attract birds from far and wide, and you’ll see a huge increase in insects like dragonflies and damselflies, all of which will come to bathe and to drink.

There is no prescription for native plant gardening. We all grow what we grow for our own reasons. One thing everybody growing native plants seems to agree on, though – we wonder why everyone isn’t on board yet.

Happy native plant gardening.

Coreopsis tripteris

August in my garden consists of a lot of yellow, and a lot of tall plants. Coreopsis tripteris (tall tickseed) is one of the newer additions to my yard and is no exception to this. It doesn’t reach the lofty heights of Agastache nepetoides (yellow giant hyssop) or Silphium perfoliatum (cup plant), but it easily tops 6’ in only its second year (and this was a very dry year here). Its leaves, too, are much more delicate than some of the other garden giants and thus it provides a very airy elegance in the flower bed. It can be a bit aggressive given adequate moisture, but if you have the room, it is a lovely plant as a backdrop. (Plant Description and In the Garden sections, below, courtesy of Shaun Booth from In Our Nature.)

Common Name: Tall Tickseed

Scientific Name: Coreopsis tripteris

Family: Asteraceae (Aster Family)

Alternate Common Names: Tall Coreopsis

Plant description: Tall Tickseed features slender, smooth, cylindrical stems that are unbranched except for along the upper half of the plant. Opposite leaves are found along the full length of the stems. These leaves are odd-pinnate with 3-5 leaflets, each measuring up to 12.7 cm long and 2 cm wide. Leaflets have smooth margins, a linear-elliptic shape, a pointed tip and a wedge-shaped base. Lateral leaflets have no leaf stalk while the end leaflets do have a leaf stalk. Leaflets are further characterized by smooth upper leaf surfaces and finely hairy undersides. The uppermost stems are topped with solitary flowers that collectively form open, loosely flat-topped flower clusters. Each flower is borne on a flower stalk that is up to 25cm long. These flower stalks may have a couple leafy bracts along them. Individual flowers measure up to 5cm across and feature 8 widely spreading ray florets (petals) surrounding a dense cluster of brown disk florets. Flowers give way to small (4-5mm), oblong, brown seeds with winged sides.

In the Garden: Tall tickseed is a stately plant with radiant yellow flowers that reach for the sky. It is valued as a dependable structural plant with noteworthy winter interest.

Skill level: beginner

Lifespan: perennial

Exposure: part shade to full sun

Soil Type: well drained

Moisture: moist to mesic (to dry) – will tolerate some drought

Height: 60-240 cm

Spread: 60-240 cm

Bloom Period: Jul, Aug, Sep, Oct

Colour: yellow

Fragrant (Y/N): N

Showy Fruit (Y/N): N

Cut Flower (Y/N): Y

Pests: no significant pests

Natural Habitat: dry to wet prairies and meadows, marshes, oak forests (especially borders and clearings), fields, roadsides and railroad rights of way

Wildlife value: flowers are visited by frequented by butterflies, skippers and native bees, and birds are known to feed on the seeds

Butterfly Larva Host Plant For: Southern Dogface butterfly (Zerene cesonia) – though this species rarely visits Ontario

USDA Hardiness Zone: 3-9

Propagation: [C(60), L; D] Easily propagated by surface sown seeds (requires light for germination) in late fall. The seeds will germinate in a week or two and overwinter as a small cluster of leaves. If planting in the spring, the germination will benefit from 60 days of cold moist stratification before direct sowing. This coreopsis is also readily propagated by dividing the root clump in early spring or after it has finished flowering in the fall.

Additional Info: If grown in light shade, tall coreopsis tends to be open and leggy with a tendency to lean toward the sun. Grown in full sun, plants tend to be sturdier and have many more blooms. As with other coreopsis, deadheading will extend the bloom period and prevent unwanted seedlings, especially in smaller gardens where this plant can be aggressive especially if there is adequate moisture.

Native range:

Invasive Species, Weeds, Nativars and Other Terms of Confusion 

The native plant gardening world is full of terminology that those gardening with non-natives have seldom had to consider. In this month’s article, I hope to shed some light on what some of these terms actually mean so that you can speak confidently and knowledgeably with garden center staff and fellow gardeners. 

Native vs Naturalized 

I started my journey into native plant gardening with the purchase of a package of “wildflower” seeds. When I recognized California poppies, bachelor’s buttons, and a few others I knew were not from these parts, I became confused. That’s when I discovered that wildflower is NOT the same as native. After a little more research, and a broken heart, I discovered that many of the wild plants I grew up loving in the fields and forests were actually European, Asian or other non-natives that had escaped from gardens over the past couple of hundred years and not the cherished native plants I thought they were. So what IS a native plant? 

In its simplest terms, the general consensus used by many but not all, is that any plants growing in an area before the European settlers arrived are considered native. These are the plants that evolved here and developed ecological relationships with the insects and birds and other animals as well as with the surrounding plants. These relationships developed over thousands of years. Europeans, as well as those from other parts of the world, came to this continent and brought plants they were used to using and or seeing, and all of these plants are considered to be non-native. Yes, plants migrate, but they do so very slowly and local ecosystems typically have time to react to any newcomers. The sheer volume and strangeness of the plants that were introduced by settlers really disrupted these natural changes. And, yes, changing climate is likely to allow plants not previously growing here to survive, but the rate of change will be nothing like the speed of putting a packet of seed in a truck in Arkansas and spreading in your southern Ontario garden a week later. 

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I don’t know when the currently accepted definition was proposed or by whom, and it leaves many unanswered questions, such as: should plants that were brought here by First Nations peoples (e.g. pawpaw – Asimina triloba) also be considered native? By keeping the definition simple, i.e. is it pre-European, the answer is also simple: yes. (There have been many long, philosophical discussions on the topic in many native plant forums. But I like to keep things as simple so this is the definition I use.) 

So what, then, is a naturalized plant? Naturalized simply means that that particular non-native species can exist in the wild without human intervention. Many of my favourite childhood wildflowers, like mullein (Verbascum Thapsus) and common chicory (Cichorium intybus), and even dandelions (Taraxacum officinale) fall into this category. Though many non-natives have adapted well to the wild, many, like zinnias (Zinnia elegans), petunias (Petunia spp.) and many of our vegetable crops, like bell peppers (Capsicum annuum), cannot survive long in our region without human intervention. Some, on the other hand, have adapted so well they are considered invasive. 

Invasive vs Aggressive 

We often hear about invasive species, and sometimes (incorrectly) an overly aggressive native plant like Jerusalem artichoke (Helianthus tuberosus), or Canada goldenrod (Solidago canadensis) are called invasive. However, the term invasive species is reserved for non-native plants that are so prolific, either because they self seed, spread vegetatively, and/or produce toxins to inhibit the growth of any competition, that they spread unchecked and have a large negative impact on the natural ecological balance of an area. Note that not all non-native species are invasive, but those that are can have devastating effects on local flora and fauna.  

They way I wrapped my head around the terminology is with an analogy: If our military forces came into a major city and started roughing up and arresting people, we’d say they are being aggressive, but if a foreign army did this, we’d say they were invading. The domestic army can’t invade because it’s already here. Same for plants – Canada goldenrod can’t be invasive because it belongs here. But a plant from another part of North America that was never here before CAN be considered invasive. For instance, cup plant (Silphium perfoliatum) was never native in New York state but it is a very aggressive spreader and is therefore considered an invasive species there1, 2 (and it is illegal to sell or grow it for sale in that state).   

Weeds 

Weed is another term that has some confusion surrounding it (I’m not talking about the weed your brother-in-law smokes, either). Weeds may be non-native OR native plants. We’re all familiar with dandelions – some consider it a weed while others do not. This Eurasian-native species was brought by European settlers as early as the 1600s as a food and medicine plant3. Plants like Canada thistle (despite its name, it, too, comes from Eurasia) were brought for the same reasons, or because they were familiar flower garden plants “back home”. These, and many more, have become ubiquitous throughout North America.  But the term weed is actually an agricultural term and describes any plant that has a negative economic impact on agricultural (food) production. In our gardens, is simply a plant that is unwanted where it is growing and in traditional gardening, these often happen to be native species, though not always.  

Erigeron canadensis (Horseweed, or Canada Fleabane) is a prime example of a native plant that is considered a serious weed in agricultural crops, especially since it developed resistance to glyphosate (the major weed-killing ingredient in Roundup) and to acetolactate synthase (ALS) herbicides. Milkweed, especially Asclepias syriaca or common milkweed, was long considered a noxious weed – a special category for the really nasty ones – and was eliminated from farm fields whenever it was encountered. Livestock won’t eat it, its rapidly spreading rhizomes enables it to take over large areas of a field out-competing the farm crops, and it had huge impacts on the farmer’s bottom line. We now know that it is also essential for the survival of the monarch butterfly, and as a result many jurisdictions have removed it from their noxious weeds lists. 


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Essentially, a weed is simply a plant growing where you don’t want it. In my all-native-plants garden, for instance, I consider squirrel-planted tulips and star of Bethlehem plants to be weeds. (I even refer to my hosta bed under a large maple tree in my front yard as my “weed garden”, and one day it will get “weeded” and native plants put in). 

Cultivars and Nativars 

Some other terms in native plant gardening also bring some confusion, especially to those just starting out. For instance, what’s the deal with cultivars and what is a nativar? The term cultivar is simply an abbreviation for the phrase “cultivated variety”. Nativar is a newer term that has come with the surging interest in native plant gardening and is simply a combination of two terms, native and cultivar.  

When many of us start to grow native plants in our gardens, we bring with us a history of growing non-natives. We, therefore, often look to the exotics for unusual colours or forms. I was no different in this regard – I was in in my 50s, with close to 40 years gardening experience, when I discovered native plant gardening.  When I saw a cardinal flower (Lobelia cardinalis) with a deep burgundy colour, a swamp milkweed (Asclepias incarnata) with a pure white flower, or a bloodroot (Sanguinaria canadensis) with a “double” flower, I was amazed and wanted it in my garden. Most often these plants are simply natural mutations that horticulturalists have latched onto and have cloned for resale. Some will breed true to the new form, but some are one-off freaks of nature whose seeds, if they even produce any, will revert to the original. Others are the result of selective breeding. And because the horticulture trade is, for the most part, driven by profit, some growers will select for unusual colours or forms to meet the demand for exotic plants.  

You can usually spot a plant in the garden center that is a cultivar because the tradition is to include the commercial name (either in quotation marks or not) after the scientific name, such as Aclepias incarnata “Ice Ballet” – note that the scientific name is in italics but the cultivar name is not. The use of var. (for variety, or in Latin, varietas) in the name, as in Cercis canadensis var. alba, is supposed to be used for naturally occurring varieties that have been selected for certain characteristics (in this case, a white version of redbud) rather than for plants that have been specifically bred for the trait. Unfortunately, there is not a lot of consistency in how these terms are used in the trade. (See article #4 in the reference list below for some more detailed explanations of these and other related terms.) 

Click on any image to view larger version.

But as intriguing as some of these unusual variations are, recent research is showing that not all cultivars/nativars are equally valuable to the insects that depend on them5. Nutritional values can vary because the genetics that produce a desirable feature may be connected to those that impact nutritional value (similar to the genetics that make a German shepherd dog look the way it does also makes it susceptible to hip dysplasia). For instance, many of the double flowered nativars either do not produce nectar or pollen – the extra petals in double flowered species is often a mutation where the stamens in a flower are replaced by petals – and are often sterile, while others may be unpalatable to the insects that need it to survive. As the interest in native gardening grows so, apparently, does our interest in nativars and ongoing research is needed to determine which varieties are just as good for the insects as the originals.  

Summary 

You should now be able to confidently explain that, no, Canada goldenrod is NOT invasive, but garlic mustard is (and why). You should also be able to explain to your neighbour why those tulips in your lawn are actually weeds, why the milkweed in your front garden isn’t, and what the difference is. And finally, when shopping for some new plants, if you see a non-Latin name pinned to the end of the scientific name on the plant tag, you’ll know this is (most likely) not a pure native species and, as such, may not have the same value to the insects and other critters that need it to survive.  

Happy native-plant gardening. 

  1. https://nyis.info/wp-content/uploads/2018/01/d8be1_Silphium.perforatum.NYS_.pdf  
  1. https://www.dec.ny.gov/docs/lands_forests_pdf/isprohibitedplants2.pdf  
  1. https://www.fbn.com/en-ca/community/blog/where-did-all-of-these-weeds-come-from 
  1. https://www.mapleleavesforever.ca/cultivar-variety-or-nativar-as-it-relates-to-our-native-maple-species/ 
  1. https://piedmontmastergardeners.org/article/native-species-or-cultivars-of-native-plants-does-it-matter/  

Monarda fistulosa and Friends

Without a doubt, the most active pollinator attracting plant in my garden (and with over 300 species of Ontario natives and a few near natives, that’s saying something) is Monarda fistulosa, aka Wild Bergamot.  While the flowers are blooming, there is constant activity with bees of all sizes – from tiny ones the size of a grain of rice to large bumblebees – and butterflies, moths, wasps, beetles and even the occasional hummingbird. These just started blooming in my southern Ontario garden in the first week of July and will keep going for a few more weeks. Though susceptible to powdery mildew, my resident bunny never touches it.

(Plant Description and In the Garden sections, below, courtesy of Shaun Booth from In Our Nature.) 

Common Name: Wild Bergamot 

Scientific Name: Monarda fistulosa 

Family: Lamiaceae (Mint Family) 

Alternate Common Names: Bee Balm, Wild Horsemint, Mint-leaf Beebalm, Purple Beebalm 

Plant description: Wild Bergamot features multiple, light green stems that are 4-angled and varyingly hairy. Opposite leaves are found along the stem, measuring up to 10cm long, 3.8cm wide and are borne on 1.5cm long leafstalks. Leaves are broadly lanceolate to ovate, coarsely toothed, hairless to finely hairy and have rounded bases with pointed tips. Branching stems are topped with 7.6cm wide clusters of tubular flowers. Each flower has a tubular upper lip, with protruding stamens and tufts of white hairs at its tips, and a curved lower lip. The outer surfaces of the lips have fine hairs. Flower heads are backed by green bracts that may have a pinkish tinge. Flowers turn into rounded seed heads that contain small, dry, oval seeds. 

In the Garden: Wild Bergamot blooms profusely with pastel purple flower-heads that resemble mini-firework displays. The leaves have a lovely minty-oregano fragrance when rubbed. The rigid stems and rounded seed heads stand strong through the winter months to extend seasonal interest. Herbivores tend to avoid this plant. 

Skill level:  beginner 

Lifespan: perennial 

Exposure: full sun to part shade 

Soil Type: thrives in a wide range of soils, from acid to lime to rich to poor to sand to clay 

Moisture: dry to moist 

Height: 60-120 cm 

Spread: 60-90 cm  

Bloom Period: Jul, Aug, Sep 

Colour: pink, lavender, rarely white 

Fragrant (Y/N): N (but foliage is aromatic) 

Showy Fruit (Y/N): 

Cut Flower (Y/N): 

Pests: powdery mildew can be a significant problem with the monardas, particularly in crowded gardens with poor air circulation; rust can also be a problem 

Natural Habitat: open wooded sites, prairie ditches, meadows, sunny hillsides & rocky slopes 

Wildlife value: Butterflies and many, many native bees are attracted to Wild Bergamot – it is one of the busiest flowers in my garden when in bloom. Hummingbirds may also visit occasionally. The aromatic foliage is unpalatable to most herbivores. 

Butterfly Larva Host Plant For: none 

USDA Hardiness Zone: 3-9 

Propagation: Wild Bergamot is very easy to start from seed, which should be surface sown because they need light to germinate, but they do not need to be cold stratified. Store seeds in a cool, dry environment for spring sowing. Colonizes by rhizomes so lift and divide every 3 years to control its spread, improve air circulation and for general plant health. Most sources recommend dividing in early spring before new growth starts, but I have successfully divided wild bergamot all summer long. Plants may also be propagated in the greenhouse from stem cuttings. 

Additional Info: Not a good choice in a boulevard garden as it has very low salt tolerance. Prefers drier soils than M. didyma. In most years in my garden, the Wild Bergamot becomes white with powdery mildew by the time the blossoms are nearly done, and I often get good regrowth and a second flush of flowers by cutting them back at this time to the lowest set of leaves. 

Native Range: 

Native Range of Monarda fistulosa

A couple more Monardas to consider: The plants below are gorgeous in the garden, but have a much more restricted range than M. fistulosaMonarda didyma is found mainly in southern Ontario, New York and Pennsylvania while M. punctata is native to the very southwestern tip of the province (Essex County and parts of Chatham-Kent) and to lower Michigan and parts of New York. Perhaps I will do a feature on these at a later date. 

Monarda didyma Bee Balm, Oswego Tea, Firecracker Plant, Wild Oregano (and several other common names, is a bright red cousin of Wild Bergamot that will grow to about 120 cm (4’) tall in well drained sand, clay or loam soils in full sun to part shade. Hummingbirds and swallowtail butterflies are especially attracted to the red flowers.  

Monarda punctata: With the least flashy flowers of the three Monardas, the gorgeous Spotted Bee Balm, aka Dotted Horsemint, makes up for it with leafy bracts that turn a glorious pink. It is also the most drought tolerant of the three. In my garden, if you want to see a great black digger wasp (Sphex pensylvanicus) just stand by the M. punctata for a few moments when it is blooming – they are almost always on the plant. 

2b or Not 2b – The Story Behind Plant Hardiness Zones

Most gardeners are familiar with the Plant Hardiness Zone (PHZ) maps that are found in many seed catalogues and garden centers, and with the paired numbering system (2a, 2b, 3a, 3b) etc. found on plant labels.  But what do these numbers really mean? How did they come about? And are they really relevant for native plant gardeners? 

The earliest PHZs were delineated in the 1920s by the Arnold Arboretum at Harvard University. In the 1960s, the US Department of Agriculture (USDA) devised their own set of PHZs using different criteria resulting in two different maps. However, the Arnold Arboretum map remained the standard until 1990, when the USDA, in conjunction with the US National Arboretum, and using data from thousands of weather stations, created the maps we now see. These maps are based on the average minimum winter temperatures. Each zone is marked at 10°F intervals, with the division between a and b at the 5° interval (e.g. zone 6a has an average winter minimum temperature of -10 to -5°F, 6b is -5 to 0°F). The logic behind this system is that plants have a cold threshold they won’t survive beyond.  

USDA PHZ: https://planthardiness.ars.usda.gov 

Unfortunately, these zones are a bit too simplified because plants are affected by more than just minimum winter temperatures, especially the further south you go. In snowbelt areas, for example, temperatures may drop well below freezing, but a deep blanket of snow can keep the plants safe. Basing the plant hardiness zone on minimum temperature doesn’t always work. Regardless of what minimum winter temperatures the plants will succumb to, some plants also tolerate heat much better than others. So the American Horticultural Society (AHS) devised their Plant Heat Zones based on the number of days the temperature went above 30°C (86°F), but their methodology created some problems as well. For instance, some plants can take lots of heat in the daytime but need cooler nights to recover and so just counting the number of days the temperature is above 30°C doesn’t really work. Also, plants like hostas love the heat, but they need cool winter temperature in order to go dormant so that they can start to grow again in the spring.  

AHS Heat Zone Map: https://ucanr.edu/blogs/dirt//blogfiles/37486_original.jpg 

If you’ve ever looked at the Canadian PHZ map, you’ve perhaps noticed that it doesn’t quite align with the USDA map. This is because the Canadian map is likely more properly called a Plant Suitability Map (though it still goes by the Plant Hardiness Zone moniker).  

Canadian PHZ: http://planthardiness.gc.ca/?m=1 

Originally developed in the 1960s, it uses a wide range of variables, not just minimum and or maximum temperature. The variables are: monthly mean of the daily minimum temperatures (°C) of the coldest month; mean frost free period above 0°C in days; amount of rainfall from June to November, inclusive; monthly mean of the daily maximum temperatures (°C) of the warmest month; winter factor expressed in terms of (0°C – X₁)Rjan where Rjan represents the rainfall in January expressed in mm; mean maximum snow depth; and maximum wind gust in (km/hr) in 30 years; and it incorporates them into a complex mathematical formula. You can read more about the formula and how it works here.

The original formula is the result of statistical analysis of the survival of 174 different trees and shrubs from 108 locations across the country (McKenney and Campbell, 2002, Getting into the Zone – what does Canada’s new plant hardiness zones map really mean? Frontline Technical Note #103 – see link to the paper at the end of this article). The newest version of the map was generated using computer models and interpolating climate data generated at more than 3400 locations across the country.  

Which is the best (i.e. most accurate and reliable) system? Being Canadian, I’m probably biased. But it would seem that the more thorough and complex Canadian system is likely the more accurate. The challenge is getting everyone to agree on one system. Most garden centers use the USDA system, probably because it has been around for a long time and the plant labels they purchase (likely from US sources even here in Canada) use that system.  

Surprisingly, even though the American and Canadian calculations are very different, in the southern Great Lakes region the results are close enough to be compatible for most of the plants – although some sources I’ve seen suggest that the Canadian and American systems may differ by as much as one complete zone in some locations. Also, both the US and Canada have been widely mapped using the USDA PHZ criteria, but I’ve not found any maps yet where the US has been mapped using the Canadian system. So, it doesn’t look like we’ll have a unified system any time soon. 

USDA Plant Hardiness Zone Map (North America): http://www.perennials.com/content/plant-hardiness-zone-maps/

But even with all the variables used in the Canadian maps, there are so many things that will affect the plant’s survivability that just cannot be easily mapped. Extreme weather events, microclimates caused by built structures, local topography, even mulching and watering, can have a significant impact on plant survival. 

When it comes to native plants, though, a lot of research is still needed to verify the zones they will survive. Accurate range maps overlaid on PHZ maps will go a long way to answer these questions, but native range of so many of our native plants have not been mapped with any level of detail.  

Then there is the question of whether we should even worry about what areas our native plants are capable of growing in – if the idea is to keep native plants in their native range, the more important issue is to figure out where the plants actually grew before we started putting them in our gardens everywhere. This way our native plant gardening efforts will better serve the insects and animals the plants evolved with, and not just our personal aesthetic.  

Until next time, happy native plant gardening. 

Rick 

Other Resources:

Blue Flag Iris

Beginning to bloom in my garden as I write this, is one of my favourites – Iris versicolor or blue flag iris. Its glorious royal purple blossoms are a real eye catcher. If you have sufficient moisture, it can be a garden show stopper in June before the bulk of the colourful summer and fall natives have started to bloom. (Plant Description and In the Garden sections, below, courtesy of Shaun Booth from In Our Nature.) 

Common Name: Blue Flag Iris 

Scientific Name: Iris versicolor 

Family: Iridaceae (Iris Family) 

Alternate Common Names: American Blue Flag, Dagger Flower, Flag Lily, Harlequin Blueflag, Large Blue Iris, Larger Blue Flag, Multi-coloured Blue Flag, Northern Blue Flag, Northern Iris, Poison Flag, Snake Lily, Water Flag 

Plant description: Blue Flag Iris features sword-like basal leaves that are usually erect but larger leaves may be slightly spreading. They are about 2.5cm wide at the base, taper gradually to a pointed tip and are often purple at the base. Smooth flowering stalks emerge from the base of the plant and are topped by 1 to a few flowers that each measure up to 10cm across. These flowers are a very familiar Iris shape with 3 sepals, 3 petals and 3 stamens. The sepals spread outwards from the center of the flower and each one has a patch of yellow and white at the base with purple veins fanning out from it. The upper lip of this sepal curves up like a shoehorn and forms an open tubular shape with the bottom lip. The petals are found in between the sepals, measure 2/3 the length of the sepals and are violet-blue with dark purple veins. Flowers are replaced by angular, oblong seed capsules that split open to release its seeds. 

In the Garden: Blue Flag Iris steals the show in early summer with its intricate, jewel-toned flowers and its bold, sword-like leaves. The flowers are relished by hummingbirds but deer and other herbivores rarely touch this plant. In addition, the angular seed pods add excellent winter interest. 

Skill level: beginner 

Lifespan: perennial 

Exposure: full sun to part shade 

Soil Type: prefers clay and mucky soils but will grow in most soils (I have seen them growing in the shoulder gravel of a road) 

Moisture: wet, moist – will tolerate short periods of drought 

Height: 60-90 cm 

Spread:  60-75 cm 

Bloom Period: May, Jun, Jul 

Colour: blue/purple 

Fragrant (Y/N):

Showy Fruit (Y/N):  N   

Cut Flower (Y/N):

Pests: susceptible to a number of insect pests including iris borer, iris thrips, and aphids and potential disease problems include various rots (rhizome rot, crown rot, bacterial soft rot) leaf spot, and leaf/blossom blight while aphids can spread mosaic virus 

Natural Habitat: marshes, swamps, shorelines, wet meadows, margins of ponds and creeks, sedge meadows and borders of wetland forests 

Wildlife value: attracts butterflies and native bees. Hummingbirds seek nectar from the flowers. 

Butterfly Larva Host Plant For: none 

USDA Hardiness Zone: 2-7 

Propagation: [C(120), M; D] Seeds should be sown when fresh or, if sowing later, stored in a cool, moist setting (most sources say they do not tolerate drying out – though Cullina claims they do just fine stored dry). They require at least 4 months cold, moist stratification to germinate and will take 2 years till they produce flowers. To propagate vegetatively, the roots can be divided in early summer and potted or planted along the water’s edge. 

Additional Info: In smaller water features, consider growing this in large pots submerged to the rim. 

Native Range:

Iris versicolor is a northern native, growing along streambanks, lakes and ponds, and in open wetlands.
Book Review:  The Northeast Native Plant Primer: 235 Plants for an Earth-Friendly Garden

Book Review: The Northeast Native Plant Primer: 235 Plants for an Earth-Friendly Garden

The Northeast Native Plant Primer: 235 Plants for an Earth-Friendly Garden

By Uli Lorimer

  • Publisher: ‎Timber Press, 2022
  • Paperback‏:‎ 252 pages
  • ISBN-10: ‏ 1643260464
  • Dimensions: 8” X 9”
  • Price: $31.94 (Amazon.ca); $22.46 (Amazon.com)

A beautiful but brief synopsis of native trees, shrubs, vines, wildflowers, ferns, grasses, sedges and rushes suitable for gardens in the northeastern US and southeastern Canada (from the Maritimes through southern Quebec and into southern Ontario).

I’ll start by saying that the quality of the book and the images is fabulous – just what I’d expect from Timber Press. I love just looking at the pictures. Unfortunately, at least from a serious native plant gardener perspective, that’s about where it ends. Like its predecessor – The Midwest Native Plant Primer: 225 Plants for an Earth Friendly Garden by Alan Branhagen – it falls short in so many ways from becoming a truly useful book. The one MAJOR improvement over the Midwest Primer is that in this book, at least, the plants are listed in alphabetic order by scientific name. For one thing, this keeps all the similar plants (e.g. milkweeds, oak trees, etc.) together in the book. And for another, it overcomes the issue of the huge variability in common names found throughout the region.

The book starts, as this genre usually does, with an introduction covering a variety of related topics. These include such things as: the definition of a native plant, expecting and living with change as your garden evolves, straight species vs cultivars (Lorimer believes, as I do, that the straight species is always the better option), preparing the new garden bed, soils, moisture and light, etc. The intro also includes a fairly lengthy section listing the plants in the book that are hosts for various moths and butterflies and which moths and butterflies those are. Finally, the book also includes some simple icons with each plant indicating if the species is valuable for birds, pollinators, butterflies, caterpillars and/or mammals, reptiles and amphibians.

That’s what I liked about the book. Now for where I felt it let me down and could have been more useful.

It states in the intro that each profile includes information on current scientific name, common name, native habitat, height at maturity, light requirements, wildlife value and a description of the plant. It does. Sort of. The level of information is so brief, however, that I came away feeling like I needed more information. One short paragraph covers all of this info. There is little or no information on propagation, on WHERE in the northeast the plants are native to/can be grown, and even though the author talks about plant hardiness zones in the intro and even provides a chart at the back explaining how it works, none of the plant descriptions indicate the hardiness zone. Why was it brought up in the first place if you’re not going to include the information for each plant. But to me, the biggest flaw is that the book does not tell me if a plant is native to where I live or not. The Northeast covers a lot of real estate, climate zones, geological variability, soil types, etc. and there is no indication in the book as to where the plants are actually native to. It is my belief that native plant gardeners, more so than any other type, want to know if a plant is actually native to where they live. There are few other minor things (like only listing one common name for each plant) that do not really detract from the book.

All in all, it’s a beautiful book to look at, and can give you some ideas for plants you can try growing. It’s nice enough that even after my disappointment, I will be keeping in on my shelf as a handy, quick reference. But it really is just the starting point. Once you find a plant in it that you like, you’ve got a fair bit of work ahead of you before you will know if you should try growing it or not.

© The Native Plant Gardener 2022

Can I have continuous bloom in my native plant garden? Part 2

In my previous article, I discussed continuous blooms for the shady garden as a response to someone’s query, so in this piece I will look at plants for the “average” garden – moist to dry soils, full sun to part shade. (Unless noted otherwise, all images are from my southwestern Ontario garden.)

Part 2 – The Less Shady Yard

When I started growing native plants in my garden, I was disappointed that for much of the early part of the growing season there wasn’t much colour in my garden. Once the spring ephemerals like trilliums and bloodroot were finished in the shade garden, nothing much happened till July. It seemed to me that Mother Nature only offered native colour in the summer and fall. So that’s when I started to dig deeper into the native plant literature. It didn’t take me long to start finding the missing pieces. In this article, I will offer up some native plant choices that will help you provide colour in your garden, and food for the local pollinators, from spring right through till the snow comes.

April/May/June – May is when some of my favourite native plants start to bloom. Geum triflorum (prairie smoke) starts to blossom in early May and continues well into June. It has an unusual pink blossom, but it’s the wispy pink seed heads that give this plant its name and is the real attraction in the garden. I have seen fields of prairie smoke in Manitoba, and it does look like smoke laying close to the ground. Planted in swaths as a foreground plant, it can provide quite a show. Another interesting foreground/rock garden plant is Antennaria neglecta (field pussytoes), with its white tufts of flowers that give it its common name. Note that Antennaria is a host plant for the American Lady butterfly.

We have a couple of very low-growing buttercups that bloom very early in the spring, too. Ranunculus rhomboideus (prairie buttercup) produces yellow flowers in late April – often one of the very first flowers to blossom in my garden – and R. fascicularis (early buttercup) starts to flower about 2-3 weeks later. Prairie buttercup keeps flowering for several weeks, too.

Zizia aurea (golden Alexander) blooms from early/mid May for about a month with wild-carrot like foliage and bright yellow flowers. This is a host pant for the black swallowtail butterfly. The first time I grew one of these, I found 7 black swallowtail caterpillars on the single plant. (I have since planted many more!). I find they do self seed quite a bit, but the heavy seeds do not seem to land far from the parent plant.

The hummingbirds love my Aquilegia canadensis (wild columbine). In my southern Ontario garden, it usually starts blossoming in early to mid-May and provides that first splash of reds/oranges for the season. This tough little perennial loves to self seed, and I let it pop up anywhere it wants in my yard – from full sun to full shade, in bone dry soil to consistently moist soil. Around the same time, my Capnoides sempervirens (pale corydalis or rock harlequin) starts to flower. This delicate little flower is an annual (sometimes biennial) that blooms right through till late fall. It, too, is a prolific self seeder, and though it doesn’t tolerate as much shade as wild columbine, it doesn’t seem too fussy about moisture. Often found in shallow soils on alvars, this plant is another with a two-tone blossom – pink and yellow.

Coreopsis lanceolata (lanceleaf coreopsis) starts to bloom in late May/early June in my garden and is another long-lasting splash of yellow – staying in continuous bloom well into mid-summer. And if you have the right soil (sandy, well drained), Lupinus perennis (wild blue lupine) flowers around the same time, and is host for the endangered Karner blue butterfly.

Phlox also starts to bloom in May – Phlox divaricata (wild blue phlox) and P. subulata (moss phlox) are Ontario natives, P. stolonifera (creeping phlox) is native just south of the Great Lakes. These range from blue, to white, to hot pink. (P. subulata is very common in garden centers – look for the true species rather than cultivars – which are denoted with a name in quotation marks, such as ‘Candystripe’ or ‘Ice Mountain’.) Be warned, though, that phlox seems to be a favourite on the menu for your local rabbits.

There are lots more late-spring/early-summer natives, like Geranium maculatum (wild geranium), Tradescantia ohioensis (Ohio spiderwort), Oenothera pilosella (prairie sundrops), and even Packera paupercula (balsam groundsel), but this list will give you a good start.

July/August – this is when all the showier native plants come into their own. I personally like the yellows of Coreopsis lanceolata superimposed with the oranges of Asclepias tuberosa (butterfly milkweed) – a combination I discovered by accident when my milkweed self seeded into another garden bed. Our lilies (Lilium canadense and L. michiganense) give great shows in mid to late summer, as do many of our sunflowers, coneflowers, mountain mints, Monardas (didyma, fistulosa and punctata), and all of our Asclepias (milkweeds). Our Allium cernuum (nodding wild onion) looks lovely in part shade.  See the table (below) for a list of several more late summer bloomers.

September to snowfall – fall is the time for goldenrods and asters. (And, no, goldenrods do not give you hayfever – it’s the wind-borne pollen of ragweed that blooms at the same time that is the culprit.) Some goldenrods are very aggressive, and should only be planted in appropriately large spaces – like Solidago canadensis (Canada goldenrod), S. juncea (early goldenrod) and Euthamia graminifolia (grass-leaved goldenrod). But many are very well behaved, and even have interesting foliage and flowers. These include S. rigida (stiff goldenrod), S. speciosa (showy goldenrod) and the more unusual white goldenrods – S. ptarmicoides (upland white goldenrod) and S. bicolor (silverrod).

As for asters – take your pick. There are so many, and they range from blues to pinks to whites, from short to tall, from full sun to part shade, from dry soils to wet. A few of my favourites are Symphiotrichum oolentangiense (sky blue aster) – a full sun, medium height plant that will be covered with gloriously blue blossoms; S. novae-angliae (New England aster) – a tall, pink to purple aster that handles being cut back in early summer by 1/3 to produce a shorter, thicker plant with a profusion of flowers; S. ericoides (white heath aster) – a smaller white aster with a lacy foliage and a profusion of tiny white blossoms in full sun; and the very tall (up to 6’ or more) Doellingeria umbellata (flat-topped white aster) which loves full sun and moister soil than many of the others.

Helianthus tuberosus (Jerusalem artichoke) flowers well into the fall – but be careful where you plant it as it will spread by its underground tubers. I planted mine in a plastic 45 gal barrel, cut in half and sunk into the ground. This way I get great tasting tubers in the fall and don’t have to worry about the plant taking over my yard. (This technique works well for other spreading plants, like common milkweed, the aggressive goldenrods, and others.) Helenium autumnale (sneezeweed) is another late bloomer, as is Coreopsis tripteris (tall tickseed) and Heliopsis helianthoides (false sunflower). And many of the earlier bloomers will still be blossoming well into the fall – plants like Monarda didyma (bee balm), Rudbeckia hirta (black eyed Susan), Rudbeckia laciniata (green headed coneflower), Silphium perfoliatum (cup plant), Silphium laciniatum (compass plant), and Vernonia missurica (Missouri ironweed).

Happy COLOURFUL gardening, all season long.