New for 2021: Prairie Crocus

Beaux Arbres has a few bright, lovely Pasque Flowers plants in our rock garden. We grew this beloved European spring flower from seeds from the Ontario Rock Garden and Hardy Plant Society Seed Exchange, and offered some of our surplus for sale. However, we long wanted to get a good supply of the North American species, the true Prairie Crocus, Manitoba’s floral emblem. We tried several times and our germination was poor for this wild North American. Last winter, we acquired some high-quality, fresh, wild-collected seed from southern Manitoba and, voilà, a fine flourish of Prairie Crocus seedlings.

The wild Prairie Crocus is paler, shorter, and even fuzzier than Pasque Flower. Wildflower enthusiasts in Manitoba start scanning south-facing, well-drained, sandy slopes in April, wanting to be the first to spot a Prairie Crocus in bloom. They often report their first up to three weeks before we get a Pasque Flower in bloom at Beaux Arbres. This gives us a clue to just how early this flower can be in a sheltered, sunny spot. Because of the subtlety of its silvery lavender colouring, Prairie Crocus is most effective grown in groups. On those dry south slopes on the Prairies, Prairie Crocus some years escapes the summer drought by going dormant, but we haven’t seen this phenomenon in our plants in the Ottawa Valley. It is good to know just how drought-tolerant Prairie Crocus can be, if you are planning a xeriscaping garden.

Prairie Crocus’s seeds are tricky to germinate, but once you are past that stage, they seem to be tough and enduring little plants, with one caveat: they are susceptible to slug predation. That suggest that, in the east, they need a dry, warm, gritty site, with perhaps a gravel mulch, certainly not any organic mulch. They are great little plants for a south-facing rock garden and perhaps for a large hypertufa trough. On the prairies, they grow in thin grassland.

Prairie Crocus grows all across the Canadian Prairies, into the northern tier of US plains states and up into Yukon and Alaska. Its range extends into north-western Ontario, but it has no claim to be native to the Ottawa Valley. We are enthusiastic about it because it extends the selection of early spring flowers for feeding newly emerged pollinators, and to cheer winter-weary gardeners, without risking the invasiveness of so many of the early spring bulbs on sale at the garden centre. (“Good for naturalizing” on the packet of Chionodoxa bulbs should be a red flag that they will escape into wild areas.)

We also have a hankering to grow all the Canadian floral emblems that we can. The Pacific Dogwood, emblem of BC, is beyond our scope, and Yukon’s Fireweed is something we hesitate to bring into the garden, although it is all over the utility corridor along the Sixth Line near our farm. Nunavut’s gorgeous Purple Saxifrage is finicky this far south, although we are game to try, if we can acquire some seed. If we are willing to accept the local Prickly Rose as a stand-in for Alberta’s Prairie Rose (possible, but too rampant in the east), the other emblems are doable, in fact we are already growing many of them.

Prairie Crocus is not, strictly, new at Beaux Arbres for Spring 2021 — sharp-eyed customers spotted the first offerings of this species last summer. We expect to have a good supply for sale this spring. Watch the website for the Availability Lists in the spring.

Pasque Flower in the Rock Garden. Not native, but very charming.
Prairie Crocus

New for 2021: Early Buttercup

This cheery little flower is an under-appreciated Ottawa Valley native. Along with its early-blooming companions in the wild, such as Early Saxifrage, Prairie Smoke and Hooked-spur Violet, Early Buttercup (Ranunculus fascicularis) is a great choice to provide floral resources for newly emerged pollinators. Early Buttercup is a true spring ephemeral — the plant withers into dormancy shortly after the seeds ripen in late spring. The leaves re-emerge from the somewhat tuberous root almost as soon as the snow is gone the next spring.

Early Buttercup grows wild on only one alvar in the Ottawa Valley. It is more common on the alvars of central Ontario. Beaux Arbres’ stock of Early Buttercup was grown from seed collected in the Ottawa Valley, i.e. it is local genotype.

Early Buttercup occurs in the wild only on alvars and similar open, calcareous habitats. This gives us a clue to what it likes in the garden: full sun, sweet soil, and not being crowded by larger neighbours. Like other alvar inhabitants, it is tough, adapted to heat and cold and spring wet, and its summer dormancy allows it to endure the droughts of summer.

I am making an assumption, on this snowy day in January, that I will have Early Buttercup available in the spring of 2021. We went into the winter with a good supply of seedlings. However, I have had unexpected winter losses in the past, and I am never totally sure plants are available until I see them start to grow in the spring. I will be posting Availability Lists in the spring, as growth resumes.

Native Vines

Native vines, and where to get them, have been much discussed this summer on some native plant Facebook pages I follow. Beaux Arbres has a fine selection of native vines for the Ottawa region.

One of my favourite vines is the Glaucous Honeysuckle. Unfortunately, I forgot to collect seed from this species last year. To have some Glaucous Honeysuckle available, I layered some stems of the plants in my garden. I have only a couple of these starts left. I do have a good supply of Hairy Honeysuckle, grown from seed. Hairy Honeysuckle is similar to Glaucous, but the flowers are yellow rather than red and it flowers a little later.

chèvrefeuille dioïque
Glaucous Honeysuckle

Canada Moonseed (featured image) is not well known but it is a good vine for shade. The flowers are tiny and hidden in the leaves. If the plant is female, and there is a male nearby, the flowers will be followed by dark blue fruit. Leave these for the birds – the seeds should not be eaten by people. Canada Moonseed has attractive lobed leaves.

Virgin’s Bower seeds.

There are two native Clematis in the Ottawa area. Virgin’s Bower is a large vigorous vine, adorned with a froth of small white flowers in late summer. It flowers best in a sunny locations. Much less common and much less known, Purple Clematis has large nodding blue-violet flowers in spring. It is found in the wild in woods, but it flowers more abundantly in gardens if it has at least half-day sun. Both vines have attractive seeds heads after their flowers. Now that I have a few Purple Clematis established in the garden at Beaux Arbres, I have easy access to a supply of seeds of this elusive species, and I now have a good supply of young Purple Clematis available.

Purple Clematis on a trellis at Beaux Arbres.

American Bittersweet is, like Canada Moonseed, dioecious, that is, it has male and female flowers on different plants. Some years ago, I grew some American Bittersweet from locally collected seed, and I still have a few pots left. This plant will not flower when dwarfed by being kept in a pot, and there is no way to tell if it male or female until it flowers. Most folks, quite understandably, want a known female, since it is the bright orange fall fruit which is the decorative feature of this vine. The oldest and largest specimen in the garden at Beaux Arbres is a female and it has produced a couple of suckers. Drop me a line if you are seeking a female American Bittersweet, and I can pot up a sucker off our known female.

We grow two herbaceous vines, the dainty biennial Allegheny Fringe, and new this year, the intriguing American Groundnut. We were generously given some garden divisions of Groundnut by a loyal customer and I am propagating it from the roots. For centuries, American Groundnut has been vegetatively propagated by Indigenous people in eastern Canada for its edible roots, so this is one species where I needn’t worry too much about maintaining genetic diversity through propagating by seeds. The tubers of American Groundnut are delicious roasted.

There is one more native vine which I would very much like to be able to offer: Carrion Flower. I have tried several times to start this handsome herbaceous vine from seed but have never been successful. I would love to hear if anyone has been successful in germinating Carrion Flower.

Plant Availability, May 24

New plant availabilty List to download in PDF or Xcel formats:


Bowman’s Root plants in the nursery.

Not yet in bloom but looking very good: Bowman’s Root (Gillenia trifoliata) and its close relative American Ipecac (G. stipulata). both have starry white flowers and pretty fall foliage colour. American Ipecac ‘s range is further south and west so I expect it to be more drought-tolerant than Bowman’s Root.

A great companion for Bowman’s root is the lovely Wild Geranium.

Mountain Pussytoes are starting in to bloom. This is a very low Pussytoes with grey-pink flowers, very nice for rock gardens.

Mountain Pussytoes in the Rock Garden.

The two smaller wild Irises are budding nicely, little Dwarf Arctic Iris and mid-size Beach-head Iris.

I am a big fan of Spikenard, an imposing plant for shade with a great fruit display in the fall. They were slow to get going this spring, but are now making up for lost time.

Psst, wanna buy a clematis?

We could meet in a parking lot, wearing masks. Not necessarily at dusk, and I don’t know if I could hide the clematis under my overcoat, but the new retail normal is … odd.

I have one pot of the native Purple Clematis (Clematis occidentalis) still available of the plants from my original seed collecting. I now have this species established in my garden, but it will be a few years till I have mature plants available for sale again. This is a woodland clematis with large (for a wild clematis) purple flowers in the spring. Native to the Ottawa Valley but not at all common. It is much more restrained in growth than the abundant white-flowered Virgin’s Bower (C. virginiana). The individual plant I have for sale is 4 years old and has abundant flower buds.

I also have two pots of Fremont’s Leather Flower I am willing to sell. I raised 5 plants from seed from the Ontario Rock Garden Society seed exchange. Now, I do like to keep at least 5 plants of unusual species that I hope to collect seed from, but Fremont’s Leather Flower is one of the limestone-loving Clematis. A realistic assessment of the space I might someday have in my yet-to-be-built limestone garden (realistic assessment is a hard task for plant lovers) suggests I am never going to have the space for 5 Fremont’s Leather Flowers. So I am keeping only three.

Fremont’s Leather Flower is a non-vining Clematis from the south-eastern US. it has dangling white or lavender urn-shaped flowers in June on a clumping herbaceous plant about a foot and a half high. In the wild it is found on dolomitic glades and limestone prairies

I Purple Clematis and 2 Fremont’s Leather Flower

Rescued Marsh Marigolds

I noticed some Marsh Marigolds growing in the ditch of the dirt road that runs down the side of the farm. I also knew that the road, which was in rough shape where it slopes down to the creek, was due for some grading from the municipality. So I dug up the clump that was furthest into the road, divided it into four, and potted it up. I should have taken more. Re-visiting after the road work, I notice some of the clumps in the ditch had been uprooted, dragged, and partially covered with gravel. I rescued the roots and potted them.

In the feature photo you can see the original four, in large pots at the back, blooming beautifully. I plan to keep these to collect seeds. The plants in front are in rough shape. A few may recover in time for this year’s sales. Most won’t be salable till next year, if they recover at all.

Seed list for Seedy Saturday, March, 2020

Update March 17: We have run out of White Turtlehead, Fringed Gentian, Compass Plant, Prairie Smoke, and Nodding Prairie Onion.

To whet your appetite for wildflowers, I have posted the list of seed species Beaux Arbres will be bringing to Seedy Saturday in March. This year we have over 80 species available in seeds. New species include: Lead Plant, Compass Plant, Purple Clematis, White Camas, Dwarf Mountain Fleabane, and Bottle Gentian (featured image).

Print off the list (PDF) to help plan your Seedy Saturday shopping.

Some of the seeds I have in very small quantities, perhaps because that was all I was able to harvest, or sometimes because I think the plant is a bit specialized and will be attractive to only a few gardeners. Tall Coreopsis (Coreopsis triptera) is one such. It is a nice, easy, tall yellow daisy, but the number of gardeners who need a 7 foot plant which runs is limited. However, if you have an expanse of Big Bluestem Grass (Andropogon gerardii) and want to add colour and diversity to your fledgling tall-grass prairie, Tall Coreopsis would be just the thing. If you want a tall yellow daisy which very much stays put, I have seeds, new this year, of Compass Plant (Silphium laciniatum), tap-rooted, with elegant leaves.

Another species I have only a couple of seed packs for is Fen Grass-of-Parnassus (Parnassia glauca). Everybody loves this little charmer when they see it in bloom, but I have to warn you it is both fussy to site and very, very slow from seed – a species only patient and experienced gardeners should attempt from seed.

Fen Grass-of-Parnassus (Parnassia glauca)

Lead Plant (Amorpha canescens) is a lovely summer-blooming little shrub in the Pea family. It is slow to mature but otherwise not difficult to grow in a dry, sunny spot. Each pod has only one seed, and the hard, tightly-wrapped pods must be removed for the seeds to germinate. I suspect that folks who have had difficulty germinating this species were not using hulled seeds. I go at a small heap of the pods with a heavy marble rolling pin and some elbow grease. Some of the seeds get crushed in the process but I do manage to release many seeds. I have had great germination success with seeds I have prepared this way and now offer for sale. Lead Plant is so slow and tap-rooted, it almost never appears in the nursery trade, which is a shame.

Lead Plant (Amorpha canescens)

Dwarf Mountain Fleabane (Erigeron compositus) is a charming species, easy to geminate and easy to grow. I think anyone with a rock garden might like to have this little mat-forming daisy in quantity. It grows in the Canadian Rockies and also across the north to the Atlantic. It seems to be tolerant of the hot, humid summers of the Ottawa Valley.

vergerette à feuilles segmentées
Dwarf Mountain Fleabane in the Alpine Garden, Montreal Botanical Garden
Dwarf Mountain Fleabane in the Rock Garden at Beaux Arbres.
zigadène glauque
  • White Camas in front of orange Butterfly Milkweed.

A few species want such a long period of cold-moist stratification I have put them in little bags with moist vermiculite and they are already (December) in my fridge: White Turtlehead, Dwarf Arctic Iris, and Beach-head Iris. If you take any of these home from Seedy Saturday in March, you can place them back in the fridge until you are ready to sow them, probably when it starts getting warm about the beginning of May. Alternatively, you can sow them and place their pot outdoors to experience natural winter temperature fluctuations.

Dwarf Arctic Iris with Dwarf Hairy Beardtongue in the Rock Garden at Beaux Arbres.

Plant Now for Spring Flowers

In addition to some lovely fall bloomers — Smooth Aster, Tall Sunflower, Obedient Plant, among others –Beaux Arbres will be bringing some spring -bloomers to the Ottawa Westboro Farmers’ Market this Saturday, September 14th. Experienced gardeners know they can get a much better show next spring by planting now, rather than by waiting until next spring to plant.

Wild Columbine, Prairie Smoke, Foxglove Beardtongue are great additions to your flower garden. For the early spring rock garden, add some tiny Common Bluets, Arctic Roseroot, or Early Saxifrage. An especially lovely little plant for rock gardens is the diminutive Dwarf Arctic Iris, a wild iris very much like the Quebec floral emblem Blue Flag Iris, but only about 8″ tall.

Common Bluets or Quaker Ladies
Prairie Smoke in the garden at Beaux Arbres.

Some Wildflowers of Late Summer

Silverrod (Solidago bicolor) has delighted me this year with its abundance of cream-coloured bloom. Like many wildflowers, Silverrod is often a wispy little thing in the wild, struggling to compete. Give it its own place in a garden, and the picture above shows what it can do. The blooms are constantly abuzz with native pollinators.

Some other nice flowers from the past week:

Bottle Gentian (Gentiana andrewsii)
Clustered Prairie Mallow (Callirhoe)
Standing Cypress (Ipomopsis rubra)
Kankakee Mallow (Iliamna remota)
Great Blue Lobelia (Lobelia siphilitica)