It is extra-ordinarily difficult to capture in a photo the charm of Water Plantain (Alisma trivale). The small, white, three-petalled flowers are widely spaced on a tall but insubstantial inflorescence, which, in a photo, is mostly just not there. In life, however, the transparent scrim of little stalks and buds and flowers, held high above the water, has delicate appeal. The leaves are relatively small on long petioles, glossy and pointed, and arranged in a rosette at the base of the stalk.
Water Plantain delights in mucky soil and shallow standing water. Unlike some other desirable wetland natives, Water Plantain actually likes stagnant water, so it is a good choice for hard-to-plant, out-of-the-way corners of constructed ponds. It also tolerates a bit of drying out by late summer, so it also thrives in natural wetlands and pond edges.
Water Plantain requires full sun, or nearly full sun, to promote flowering.
This charming little wildflower deserves to be much better known and more often cultivated. Grassy foliage, glossy and attractive, grows about 20 cm tall and spreads by rhizomes to fill in an area. In mid summer, the flower stalks rise above the foliage. The initially pink buds open to white flowers. After flowering, the vivid orange-red seed capsules are as showy as the flowers were. Pretty, short, and two-seasons of interest; why is this plant not more widely grown?
The answer probably lies in the rather specialized habitats in which it grows in the wild: fens, fen-ish prairies, and calcareous shorelines. Although it will put up with less than ideal conditions in cultivation, if you want it to thrive, you should give it moist, sweet soil, lots of sun, and not too much competition. This setting is not easy to supply in many urban gardens.
It occurs to me though, that in the Ottawa exurbs, there are many residential areas on the limestone bedrock, from Almonte to Dunrobin and beyond, where gardeners, trying to grow more traditional flowers, are frustrated by the shallowness of the soil. If you have a pocket of soil on limestone which remains moist for a long time after rain, you may have just the site for some unusual wildflowers such as Sticky False Asphodel.
I think there might also be a call, in more urban areas, for not-too-tall plants for rain gardens. Larger rain gardens and drainage swales are good places for tall, lush wetland plants such as Swamp Milkweed, Blue Vervain, and Purple-stemmed Aster. Great plants, fabulous for pollinators, but quite possibly overwhelming for small-scale gardens. Plants that can endure occasional inundation but do not grow too tall would be most valuable for smaller rain gardens. In sun, you could combine Sticky False Asphodel, Bottle Gentian, Upland White Aster, and, if you can source it, Van Brunt’s Jacob’s Ladder.
It is also possible that keen native plant enthusiast and wildlife gardeners might contemplate creating a pond or water feature that is particularly conducive to growing some our fabulous native wetland plants. The stunningly beautiful Fen Grass-of-Parnassus is worth creating a fen garden to enjoy, and Sticky False Asphodel would be one of its companions in this setting.
For my webinar on Alvars for the West Carlton Garden Club earlier this month, I played with re-imaging some very modernistic gardens, pictured in gardening magazines, redesigning them as Alvar Gardens. The picture below, of an installation for the Chelsea Garden Show a few years back, shows an Alvar and Fen garden waiting to happen – slabs of limestone and shallow pools. Imagine this planted up with Sticky False Asphodel, Fen Grass-of Parnassus, and a pocket of Lizard’s Tail in one of the pools. My point is that native wildflowers can be used to create many styles of gardens, including the sleekest contemporary styles. Exploring the range of native plants beyond the well-known meadow species offers extra-ordinary possibilities for innovative gardens.
(If you missed my Alvar talk, my list of Alvar species for Ottawa gardens is downloadable here.)
Soft, silvery, foliage is a desirable decorative feature in gardens. To augment the bright silver of native Pearly Everlasting and subtle silvery-grey of Parlin’s (Plantain-leaved) Pussytoes, I now offer the silky silver of Fringed Sage. It is much more hardy than the popular but notoriously finicky and short-lived Silver Mound, the standard garden centre offering. Compared to the neat rounded shape of Silver Mound, Fringed Sage (Artemisia frigida) is informal. Indeed, it can look a bit unkempt during flowering. If you want a low, neat effect, trim the flowering stalks as they form in mid-summer to promote attractive silvery bushiness for the autumn garden.
Fringed Sage requires dry, infertile soil and full sun; it does not survive in seasonally wet sites. It prefers an acidic soil. Fringed Sage is technically a sub-shrub, that is, it has a woody base. The woody structure can be pruned lightly to help shape an individual plant. If you have the space, consider growing Fringed Sage in a mass planting, to emphasizes the lovely soft silvery effect. The little bushes are rhizomatous and will, in time, form a ground-covering mat, easily limited by shade from taller neighbours.,
Fringed Sage has a large range in western Canada, extending north into North West Territories and Yukon. It does not occur naturally in the Ottawa Valley. There are a large number of Sage or Sagebrush species native to western Canada but only one native to eastern Canada, Field Sagewort (Artemisia campestris) and it is biennial and not especially decorative.
The flowers of Fringed Sage are wind-pollinated so it is of no interest to pollinators. The aromatic foliage is not eaten by deer or other mammals. On their native prairies, Sages have several specialized insect herbivores. In our area, Field Sagewort is eaten by certain insects, and they may also eat Fringed Sage.
I have not yet tried it, but I read that leaves of Fringed Sage can be burnt on campfires to repel mosquitoes.
This is an oddity for sure. A lanky plant, 30 to 60 cm tall, with undistinguished leaves and small cream or pale green flowers, it is an unlikely candidate for inclusion in our gardens. Ditch Stonecrop’s only ornamental asset is its colourful seedpods. In late summer, the capsules turn pink — grown in sufficient sun, they turn a bright pink.
Ditch Stonecrop (Penthorum sedoides) grows in damp ditches, often in some shade. However, at least half day sun is better to bring a bright colour to the seed capsules. It tolerates shallow standing water so it could be grown in the shallow shelf area of preformed ponds. It thrives in mucky soil. Ditch Stonecrop spreads by rhizomes.
I appreciate late colour in our garden, and interesting shapes to contrast with the ubiquitous daisy shape are especially valuable. A few customers saw the colourful pods last summer and were intrigued. Is this a plant for everyone? Hardly, but if you have a damp ditch, or a natural pond edge, and would like some late season pink, then Ditch Stonecrop might be the right plant for you.
The very first flower at Beaux Arbres is almost always a little non-native rock garden Iris, Iris reticulata. Although I discourage the use of many of the little bulbs from the garden centre, because they readily leap from garden to woodlands, I have never seen nor read of any problem with the little Irises. At the same time, Payson’s Whitlow-grass, a little yellow Draba from the northern Rocky Mountains, blooms in a small pocket of soil in the south facing rock garden. Within a week or so, these early pioneers are joined by several more ground-hugging sun-loving stalwarts of the early spring garden.
The little spring flowers of the deciduous forest – Trout Lillies and Bloodroot and others — are recognized by most fans of wildflowers. Early spring flowers for open sunny places deserve to be better known.
(Pulsatilla nuttalliana) The great spring wildflower challenge in Manitoba is to be the first to spot a Prairie Crocus blooming on a south-facing slope. The native range of Manitoba’s much loved floral emblem extends, just, into western Ontario. We can grow this lovely wildflower in our Ottawa Valley gardens to enjoy their lovely, fuzzy, and very early blooms.
(Ranunculus fascicularis) This cute, low-growing native buttercup carpets the ground on alvars (limestone pavements) in Central Ontario. In the Ottawa Valley, it grows on only one area but it is abundant there. As the photo shows, it can grow where the soil is very shallow. It escapes the searing heat on the rock surface in the summer by going dormant after ripening its seeds in June. Early Buttercup persist on alvars that are grazed because it is avoided by herbivores, and that includes deer.
(Micranthes virginiensis) The flower buds of Early Saxifrage can be seen in late winter, nestled deep in the centre of the rosette of fleshy, evergreen leaves. The flowers stalk lengthen and the little white flowers open with warming temperatures. The basal rosettes often turn an attractive red with cooling temperatures in the fall. This adaptable little native can grow in almost no soil.
(Viola adunca) This is a small violet of infertile, sunny places. It is sometimes called Early Violet and it does bloom very early in the spring. In the Ottawa area, it grows on sandy hills and on open alvars. Like other violets, it is a host plant for Fritillary butterflies. It is too small to compete with lawn grasses – this is not one of the native violets which grows in lawns. Hooked-spur Violet is a lovely native addition to sunny rock gardens.
(Geum triflorum) The nodding pink flowers of Prairie Smoke emerge very early. The most noticeable part of the flowers, the crazy pink jesters’ caps, are sepals; the actual flower is a cream or pale pink flask, within the jester’s cap, that never opens. Bumblebees force themselves into the centre of the flower to pollinate it. As the flowers fade, they turn and face upwards, and the ripening seeds extend a mist of smoky purple-grey. Hence the name. The leaves of Prairie Smoke persist into the fall and green up early in the spring. Prairie Smoke will slowly fill in but it does not run about. Its low, tidy habit and two seasons of interest make this a very popular choice for the front of a border.
The very glossy, evergreen leaves of low-growing Goldthread (Coptis trifolia) are most attractive, but before you start thinking this may be the ideal shade-loving ground cover for your shady garden, be aware that this little cutie demands a cool, acidic organic soil, and is not suited for warm urban conditions. It grows in damp moss under conifers and it sometime covers very old, decaying stumps, to lovely effect. When I lived in Toronto, I became accustomed to seeing Goldthread in only the coldest and most organic spots. So I was delighted, and a bit surprised, to see Goldthread in a woods near Beaux Arbres, romping along the side of an old logging track, in partial sun no less, forming an extensive low ground cover, even weaving in and out among the grasses and hawkweeds and other weeds in the trackway, finding the ordinary leaf litter and needle duff sufficiently organic for it to thrive. It is worth remembering that, compared to almost any spot in southern Ontario, this old track has cool and acidic soil. Still, it showed what is possible in the Ottawa area, if the right conditions for Goldthread are present.
Goldthread blooms in early spring. The pretty white flowers, with a boss of white stamens, are very briefly open. The white petal-like parts are actually sepals, and the true petals are modified into yellow nectar cups. If you can catch its very brief flowering, it is worth giving the flowers of Goldthread a close look. I have not been able to find out much about Goldthread’s pollinators but those little cups, brimming with nectar, suggest it is an important food source for somebody.
The plant spreads by thin rhizomes, which are bright yellow, and give the plant its common name. An older botanical name is Coptis groenlandica, the reference to Greenland giving us a clue to its preference for cold places.
Goldthread is one of the little woodlanders I will have in small quantities this spring. Although indisputably native to the Ottawa area, it is so little adaptable to urban conditions, I find it difficult to guess what the demand for it may be. Away from the downtown heat island, in a very well shaded garden, it might be worth trying Goldthread in, say, a wooden trough filled with a specially prepared soil mix (lots of well-rotted needle duff), with other charming miniatures, such as Common Wood Sorrel, Creeping Snowberry, and Bunchberry.
The tiny white seeds of Starflower (Trientalis borealis) are easy enough to collect but I did not have great success germinating them. So I have only a handful of plant available for Spring 2021. I have no idea how popular this quiet but charming little woodlander will be. I can imagine folks who love the north woods might like it. It seems quite adaptable to a variety of shady situations, under conifers and deciduous trees.
Starflowers grows scattered throughout the woods at Beaux Arbres, in sites both moist and dry. (The soil at Beaux Arbres is mostly sandy and moderately acidic.) Their stems of whorled leaves resemble another woodland plant, Indian Cucumber Root (Medeola virginiana) but Indian Cucumber Root is much less common in our area, and occurs almost exclusively in relatively rich, moist bottomlands. In our woods, Starflower never masses to make a notable floral display. I don’t know if it is possible to coax it to do so in a garden situation. Worth trying, for the little starry blossoms have a lovely simplicity. They are also botanically interesting, for they are one of the very few flowers which have seven petals.
The indispensable William Cullina, who is only garden writer I know of who has taken Starflower seriously, has this to say about it:
[I]t adds a note of diversity and authenticity to naturalized plantings and woodlands, and I think it looks lovely growing among mosses, wintergreen, partridgeberry, and others.
The New England Wildflower Society Guide to Growing and Propagating Wildflowers of the United States and Canada, 2000.
Starflower has recently been put into the genus Lysimachia, with the yellow-flowered native Loosestrifes, such as the very pretty native Swamp Candles (Lysimachia terrestris). Thus Starflower should be properly called Lysimachia borealis, but most books and websites will have it listed as Trientalis borealis.
Partridgeberry is one of the low evergreen vines that cover the forest floor in northern woods. It can easily be distinguished from Twinflower, Trailing Arbutus, and Wintergreen by the distinct pale midrib down the centre of each leaf. Although Partridgeberry comes into its own in damp conifer woods, it is also found in mixed forests, which suggests it is not quite as dependent on strongly acidic soils as the others.
Beaux Arbres expects to have Partridgeberry plants available in the spring. Last summer, when walking through the woods of our good friend on the next concession, I came across an enormous, dense patch of Partridgeberry, forming a thick and extensive ground cover. I had never seen such a lush display of this plant and it required that I re-evaluate my opinion of Partridgeberry’s potential value in the garden. Margaret generously allowed me to take cuttings from this patch (which didn’t make the slightest dent in its abundance) and as soon as they are well rooted, I will offer them for sale.
I prefer to grow from seeds, which creates genetic diversity, but for a few of the sprawling woodlanders, which are slow from seed but easy from cuttings, it is just more practical to propagate from cuttings. Creeping Snowberry is another little evergreen that is much easier from cuttings. If I can ever offer the handsome Pipsissewa (Chimaphila umbellata) — a long-term goal, not imminent — it will have been propagated from rooted offsets, as this glossy evergreen ground cover plant is impossible to grow from seeds in cultivation.
Although only a mile away from us, the headwater wetland in the woods behind Margaret’s farm is wetter and more acidic than almost anywhere on our farm. Some beautiful little plants, such as Bunchberry and Trailing Arbutus, flourish there, but the cold, organic, acidic conditions gives us clues as to why these lovely plants can be challenging to establish in urban gardens.
Feature photo, of Partridgeberry, above: Ryan Hodnett, via Wikimedia Commons
This lovely and little-known wildflower from the western prairies also grows in prairie remnants in south-western Ontario. Although it is not at all related to the florist’s Baby’s Breath (which is considered a noxious weed in the prairie provinces), Prairie Baby’s Breath (Euphorbia corollata) contributes an airy filler effect to a meadow or flower border, in a manner similar to the way florist’s Baby’s Breath fills in a bouquet. Its wispy nature is unlikely to overwhelm border companions and it is great at finding suitable space for itself in an informal meadow planting. And, yes, you can use it as a cut flower in a bouquet — what looks like petals are actually white bracts (the flowers are the tiny things in the centre) and that gives it a longer vase-life.
Prairie Baby’s Breath, aka Flowering Spurge, wants lots of sun and lean, well-drained soil. Good companions might include mid-height prairie species such as Smooth Aster, Little Bluestem Grass, Grey Goldenrod, and Butterfly Milkweed. Prairie Baby’s Breath blooms from mid-to late summer and is usually knee high, although it can become longer and floppy in moist, rich soils. It is highly deer-resistant.
The nodding flowers in mid to late spring are modest to our eyes but extraordinarily attractive to all manner of forest pollinators. Although usually pale lavender in colour, the flowers of Virginia Waterleaf in the wild can be pure white, a nice mid-range purple, or pale pink. The distinctively lobed leaves emerge in the spring spotted with silver. It is the silvery spots which give the plant the name Waterleaf. Alas, the pretty spots fade as the leaves mature.
Virginia Waterleaf spread by rhizomes and by seeds so, where it is well suited, it can easily form a robust ground cover. It prefers dappled deciduous shade and it is tolerant of heavy clay soils. Thus it is an excellent choice for shady city gardens with compacted soils. If summer droughts have left the foliage looking tattered, the plants can be cut down and they will produce a crop of fresh leaves for autumn.