This hypertufa trough, planted only weeks ago, is doing remarkably well. I used a technique I read about in the North American Rock Garden Society quarterly, and sandwiched a thick clay mud between vertical slabs. One would think that the little Erigeron pinnatisectus or Feather-leaf Fleabane, perched at the top, would not have had a hope of surviving, but this is a plant of steep slopes and high ledges, and it seems to be thriving. Let’s see how this little garden survives the winter.
The long, blistering-hot dry period we just went through proved the garden value of a pretty, hardy succulent from the American mid-west. Rock Pink (Talinum calycinum) is a member of a genus which includes some summer-rain-intolerant species from the Rockies, collectively called Fame Flowers.
We are growing Rock Pink for the first time this year. It produces lovely vivid purple pink flowers on long wiry stalks, above the succulent green foliage. The flowers do not open until noon, last only one day, but are continuously replaced by new blooms.
Rock Pink’s home range is Texas to Illinois. William Cullina of the New England Wildflower Society, who is usually a pretty reliable authority, says the plant is hardy in Zone 4 if given excellent winter drainage. A south-facing rock garden would be an ideal home for this plant, in the north. We have recently planted several in groups of five and seven or more in our newly expanded rock garden. With the flowers a bit on the wispy side, they seem to call out for planting in groups. We need some vivid colour and we can certainly use a plant which loves heat in our summer garden. It is visited by bees.
Beaux Arbres has this plant for sale in the nursery, if you would like to give it a try. I cannot absolutely guarantee it will be winter-hardy but it is both charming and easy to raise from seed. It might even spread a bit by volunteer seedlings.
I am almost too busy getting the plants ready for the sale to blog about them but there are a few new species that are too interesting to ignore.
Seeded earlier this year and already big enough to plant now, the lovely biennial Swamp Thistle (Cirsium muticum). I know, Swamp and Thistle. Don’t let your experience with weedy non-native thistles, neither the stately but dangerous Bull Thistle nor the absolutely appalling Russian Thistle, put you off this great native for damp spots. It is so unlikely to seed into gardens that I suggest you collect some seeds in the fall to ensure you don’t lose it. I received my seeds as a generous gift from Lis Allison, whose Pine Ridge Studio, near Carp, is a great source for locally grown native ferns. Native thistles are great nectar sources for butterflies and the nutritious seeds feed many birds.
Also new this year: Dwarf Arctic Iris (Iris setosa var. arctica), a miniature wild iris and seriously cute. We have some in bud. Seriously cute. Shop early.
We are bringing a few pots of Rock Whitlow-grass (Draba arabisans). Perhaps not the most exciting of Drabas — the really tiny, exciting ones are all denizens of either the high Arctic or Alpine peaks and dislike hot weather — but we just this past Sunday saw this species used very effectively in the Natives area of the Alpine Garden of the Montreal Botanical Garden (featured image). This Draba species is an easy plant for rock gardens, small enough for troughs.
And speaking of rock gardens, yes, we will have lots of Common Bluets, still happily blooming.
We will not be bringing many shrubs to the sale this year — three species of roses, some Shrubby Cinquefoil, a few others. Plan to come out to the nursery for more shrubs.
The Fletcher Sale is the only time we bring the mid to late summer meadow flowers into Ottawa. They won’t be in bloom now, of course, but take the opportunity to add some great heat-loving natives, for flowers throughout the summer. Many of the prairie and meadow flowers are important nectar and pollen food sources for diverse pollinators: Boneset, Great Blue Lobelia, Cardinal Flower, Swamp Milkweed, diverse yellow daisies and many others. New this year: Rattlesnake Master and Tall Coreopsis.
The hypertufa troughs I made last fall weathered over the winter (to wash out alkali from the cement) and now comes the fun part: Planting them!
This trough, which broke along one side when unmoulded, was especially fun to do. I call it “Strata Garden.” It is modelled on the popular Crevice Garden style but with horizontal strata. The plants are all native to local alvars and include:
by Trish Murphy
This article was originally published in OHS News, April, 2018, the newsletter of the Ottawa Horticultural Society.
One of the things we think we know about violets is that they grow in shade, shyly, among mossy rocks. The other thing we think we know about violets is that they invade lawns.
Many species of native violets do grow in moist shady places A couple of species of native violets, notable the Common Violet, will invade lawns, a tendency which you might think charming or a nuisance. What is less well known is that there are violets for dry sunny places, charming little plants that are ideal candidates for sunny rock gardens.
We grow two of the sun-loving violets in the rock garden at Beaux Arbres. The locally native Hooked-spur or Early Violet (Viola adunca) is one of the earliest native flowers to bloom. It is a small plant, only about 2” tall, covered in small violet blooms in early May. The plant is very well behaved – the stem emerge from a central crown each year. It might seed gently in the rock garden – and volunteers are always welcome with us – but the plant is too small to compete with lawn grass.
The second sun-loving violet we grow, Bird’s Foot Violet (Viola pedata) (featured image) is a very special flower from Carolinian Ontario, where it grows in Turkey Point Provincial Park and a very few other locations. It is more widely distributed in the US but it is threatened by habitat loss throughout its range. Bird’s Foot Violet has finely divided foliage, quite unlike that of a typical violet. The flowers, with a prominent yellow central boss, are relatively large for a wild violet. The plant is in bloom for a long period in the spring and will often re-bloom in late summer. Last year, the cool wet weather encouraged Bird’s Foot Violet to be in bloom almost continuously, which is an amazing feat for a native wildflower. This lovely little flower will certainly not invade lawns and is quite shy about offering volunteer seedlings even when we encourage it to do so.
Both of these these violets like full sun in the spring and lean, sandy soil. They can tolerate a bit of shade as the summer progresses, but not too much.
One of the best reasons for growing sun-loving violets, apart from their charming bloom, is to attract and provide food for Fritillary Butterflies. There are several species of fritillary in the Ottawa area and, as caterpillars, they all eat violets, diverse violets but only violets. The smallest species, the Meadow Fritillary seems to seek out violets wherever they are. We often see them laying eggs on or near the Common Violets in the damp end of our lawn. I have had to stop the mower, sometimes giving up on the idea of mowing that day, while the Meadow Fritillaries are intent on egg-laying.
The largest and most glamorous fritillary is called the Great Spangled Fritillary, a very beautiful butterfly, almost as large as a Monarch. Great Spangle Fritillaries are creatures of warm, sun-lit spaces and they don’t seem willing to venture into the shade to find violets. They are so well adapted to dry, sunny environment that they have the ability to discern violets, even if the violet foliage has shrivelled in a dry summer and all that remains are the roots below ground. The mama butterfly will lay her eggs on the ground, in anticipation of the violet’s leaves emerging with damper fall weather.
Great Spangled Fritillaries are quite common at Beaux Arbres, probably because we have so many Hooked-spur Violets growing, not just in the rock garden but abundantly on the dry hills behind the barn.
If you are interested in providing host plants for butterflies, be sure to include some of the lovely little sun-loving violets in your garden plans.
It was wet. We expect the swale garden and the lawn below it to be wet in April and well into May, from snow melt running down from the hills which surround us. This year it was continuously and unrelentingly wet until late July. The swale was continuously full of water, which would be lovely if that is what we had planned, or if that is what we could count on. Some of our wildflowers, selected to be able to cope with a few weeks of standing water in the spring, drowned when subjected to several months of standing water. Even the rock garden (featured photo), planned as a summer-dry garden, was under water for several hours after some of the heaviest downpours.
We had hoped to burn part of our tall-grass prairie bank in early spring but it was too continuously rainy. Even without the benefits of a spring burn, the bank was showing a nice amount of colour by the beginning of August, in time for the Pontiac Gardens and Gifts Tour.
Some of the swale plants flourished:
With all the rain, the tall yellow daisies of late summer were HUGE.
My proudest moment was when the seed-grown Wood Lilies in the rock garden flowered for the first time. They were grown from seed collected in Bristol Township.
New endeavour: hypertufa troughs to show off tiny alvar and arctic gems.
I have started propagating some fen and alvar species such as this lovely Grass-of-Parnassus. Their seedlings are tiny – it may be a few seasons before i can offer them for sale.
New in the nursery for 2018: forest floor plants, started from cuttings. I know city gardeners want more native options for shade.
Other new species:
We added a hoop house, so we can have more plants in bud for the Rare and Unusual Plant Sale in May. This isn’t intended to be an all-season nor a heated green house. We just want to be about 7 – 10 days ahead of the season for Mothers’ Day.
I potted up well over than two thousand plants during the summer and tucked them all in for the winter, so we are in good shape to bring lots of native diversity to the spring sales.
Charming and diminutive plants from Ottawa Valley’s natural rock gardens
Species from slide show, in order shown
Early Saxifrage (Micranthes virginiensis)
Early Buttercup (Ranunculus fascicularis)
Common Bluets (Houstonia carulia)
Long-leaved Bluets (Houstonia longifolia)
Hairy Beardtongue (Penstemon hirsutus)
Dwarf Hairy Beardtongue (P. hirsutus var. pygmaeus)
Field Pussytoes (Antennaria neglecta)
Hooked-spur or Early Violet (Viola adunca)
Bird’sfoot Violet (Viola pedata)
Eastern Wild Columbine (Aquilegia canadensis)
Harebell (Campanula rotundifolia)
Wood Lily (Lilium philadelphicum)
White Camas (Ziggy) (Zigadenus glauca or Anticlea elegans ssp. glaucus)
Upland White Aster (Solidago ptarmicoides)
Three-toothed Cinquefoil (Sibbaldiopsis tridentata)
Bearberry (Arctostaphylos uva-ursi)
Grass-of-Parnassus (Parnassus glauca)
Sticky False Asphodel (Tofieldia glutinosa)
Carnivorous Plants: Pitcher Plant, Sundew, Bladderwort
Dwarf Canadian Primrose (Primula mistassinica)
Dutchman’s Breeches (Dicentra cucullaria)
Spring Ephemerals: Spring Beauty /Trout Lily /Toothwort
Wild Ginger (Asarum canadensis)
Foam Flower (Tiarella cordifolia)
Mitrewort (Mitella diphylla)
Broad-leaved Sedge (Carex platyphylla)
Trailing Arbutus (Epigea repens)
Twinflower (Linnaea borealis)
Creeping Snowberry (Gaultheria hispidula)
Common Wood Sorrel (Oxalis montana)
Gaywings (Polygala paucifolia)
Tall Sunflower (Helianthus giganteus)
Why Use Native Plants
Bringing Nature Home: How You Can Sustain Wildlife with Native Plants by Doug Tallamy
Doug Tallamy – Earth Optimism Summit 2017 https://www.youtube.com/watch?v=Ky5e4lPmA0U