Lovely people of the internet! My blog has moved. You can now find it at www.jadecypress.wordpress.com, but this site here still contains my writings about Fabaceae and Ericaceae, both written from a prairie gardener’s perspective. You can also follow me on Twitter (@cbcgardener) and you are welcome to e-mail me. (email@example.com) My first book will be published in spring of 2014.
Pieris- There are seven species of Pieris, all of which have been extensively hybridized with each other. Most are quite easy to grow, they are long lived, and they do well in containers. They are also quick to mature, gorgeous, and have no pest or disease issues. They are among the easiest plants in the Ericaceae family to grow.
Pieris is sometimes called lily of the valley bush, because the white flowers really do resemble those of lily of the valley. Most grow 6-9 ft. tall and wide, and all of them are evergreen. They make excellent hedges, and the flowers appear usually from late winter through spring. The new growth is often coral colored or red or pink, and this makes them especially showy. Pieris does not suit every climate, but where it does work, it is often used quite extensively. These shrubs want a cool, moist climate and cannot handle the intense heat of the tropics. They are often seen in Portland, San Francisco, Auckland, Sydney, and other coastal cities. They are resentful of a very windy site, and they can burn in very hot afternoon sun. A dappled light suits them best, or morning sun with afternoon shade. They are not fussy about soil (which is odd for this family) but they do like generous amounts of compost and good drainage. They are usually propagated from cuttings.
Pieris Formosa (previously P. japonica) is the most common species and hails from the Himalayas. It is a large shrub rarely exceeding 10 ft., with glossy, long leaves and white or pink tinted flowers. It is the parent of most of the hybrids. ‘Mountain Fire’ has brilliant fiery red new growth and flowers prolifically. ‘Purity’ is late blooming and popular, and the ‘Valley’ series (available in colors such as deep pink and nearly red) are also much sought after, though they are slower growing. ‘White Rim’ is a very handsome variegated form and ‘Forest Flame’ is a very profuse bloomer with new growth shaded heavily in red or pink.
Pieris makes a good shrub for a sunroom or a conservatory and is not a difficult plant to acquire; next time you go to Victoria be sure to look for it at your favorite garden center!
Phyllodoce- There are five species of Phyllodoce, all from the Arctic and a few high mountains in eastern Asia and North America. They have alternate, linear leaves and bell shaped flowers in spring and summer. A moist, acidic, peaty soil with cool temperatures suits them best. They can be propagated from seed (with great difficulty) but layering is much easier. They aren’t cultivated very often largely because they find most garden conditions too warm and windy for them. They are usually low growing shrubs or perennials and are generally wider than they are tall.
Phyllodoce aleutica is found in eastern Asia and Alaska. It has yellow-green, urn shaped flowers in late spring and is hardy to at least zone 2, but it is generally resentful of cultivation. P. caerulea is from high mountains in Japan and has showy purple flowers. Closer to home, P. empetriformis is fairly common in the Rockies and usually known as red mountain heather. It grows about 12” tall and is frequently found in subalpine and alpine meadows near the tree line. (I have seen it on a number of occasions while hiking in Kananaskis.) It has tiny, needle-like leaves and variable flower color. They can be nearly red through deep pink to magenta and are very beautiful. This species actually hybridizes with P. aleutica where their ranges overlap. The resulting plant (P. x intermedia) can be found in several places in Alaska and British Colombia and is quite showy. It grows about 10” tall and produces brilliant rosy-pink flowers. It is more tolerant of warm summers than either of its parents and is sometimes cultivated. ‘Drummond’ is a cultivar of it with dark purple rather than pink blossoms. I’ve heard that it puts on a great show at the Denver Botanic Garden but I wasn’t there at the right time of year to see it in flower. Special thanks today to Dr. Jody McMurray for letting me use several of her red mountain heather photos!
Oxycoccus- Previously placed in the genus Vaccinium, there are now three recognized species in this genus and most botanists agree that this is indeed a distinct group. Oxycoccus macrocarpus is much better known as the cranberry, and this is the cranberry of commerce. These plants should not be confused with Viburnum, a large genus of shrubs that also bear the name of cranberry but are unrelated, nor should they be confused with the lingonberry (Vaccinium vitis-idaea).
All of the true cranberries are evergreen, creeping shrubs that grow in bogs, muskegs, and marshy areas, although they can sometimes also be found in plains and rocky fields if moisture is adequate. These plants have tiny, thread-like roots that are easily disturbed and this makes their cultivation difficult. Wet, light soil or sphagnum is their preferred growing medium and they cannot tolerate any degree of drought. Cranberries are abundant from northern Manitoba all the way to Newfoundland and south into Arkansas and the Carolinas. They were much loved by our aboriginal peoples and in the 1770’s, British explorer Samuel Hearne and his party were drawn to what is now Churchill, Manitoba, in search of these plants. The Brits were quick to embrace this new world berry, and huge expeditions were mounted in the fall to gather the berries, pack them in water, and ship them back to England.
Cranberry is rather an unassuming little plant with tiny, oval leaves that are dark green above and pale beneath, and tiny pink or white flowers in July and August. These give way to berries that are remarkably large given the size of the plant. Berries ripen in October and November and are much sweetened by frost. They are a major food source for birds, small animals, and even bears. They are high in Vitamin C and anti-oxidants and are considered highly nutritious. Cranberries are rarely attempted as a crop, although wild stands are heavily “managed”. Water levels in the bogs where they grow are often strictly controlled, allowing them to be flooded when the berries are ripe. The berries float and are then easily harvested. Cape Cod in Massachusetts is famous for its cranberry bogs.
Although they are hardy enough, the cultivation of cranberries is rarely attempted by gardeners. Their need for constant moisture, very specific soil conditions, and general lack of availability from garden centers has made them a plant that everyone has heard of, but would seldom recognize. Assuming that growing a cranberry in your garden was easy, you still might not want one. Although attractive, they are not showy plants and would be easily overshadowed by pushier, more vibrant citizens of the garden.
Menziesia- There are seven species in this genus, all from east Asia and North America. They are rarely cultivated, but they make good understory shrubs and are quite tolerant of shade. They are good filler with other acid loving plants such as azaleas and camellias, and can be propagated from cuttings fairly easily. The best known species is probably Menziesia ferruginea, a very common shrub of the Rockies also called fool’s huckleberry. The foliage strongly resembles that of azalea or rhododendron, but is less glossy and has a strong, skunky odor when crushed. The pale salmon-pink blooms closely resemble those of huckleberry, and many hikers find a clump of these and return later in the season, hoping to find fruit! These shrubs do not produce fruit, and indeed they contain potent toxins and are poisonous if ingested. This shrub is difficult to grow in gardens as it favors high elevations and cool temperatures, but I’m thinking about experimenting with it. It grows 3-4 ft. tall and wide and will sometimes turn beautiful shades of orange or yellow in the fall; I saw it in Waterton in September doing just that, but the best color seems to be at the higher elevations. I took photos of it, none of which captured how gorgeous it really was, but I tried. Anyway, here’s a photo of it in bloom, but this I just got off the internet.
Ledum- There were originally three species in this genus, but recently DNA testing has proven that these plants are actually much more closely allied with Rhododendron than anyone realized, and they have all been reclassified as such. I’m not sure how I feel about this re-organization. I think I am rather opposed to it. I am still going to treat Ledum as its own genus, at least for now.
The best known species is L. groenlandicum, much better known as Labrador tea. Usually reaching about 3 ft. tall, this evergreen shrub can occasionally be as tall as 4 or 5 ft. It has dark green leaves with distinctly rolled margins, much paler beneath and the stems and branches are coated with a noticeable reddish fuzz. The flowers appear in June and July, in small clusters, and are pure white in color. On close inspection, they do look a lot like little Rhododendron blossoms. I have to admit that while there is definitely a family resemblance, that doesn’t necessarily mean they are the same thing. (Damn you, genetic testing, damn you!) They will often grow in large groups where conditions suit them, and they favor bogs in wooded areas and places along streams, usually where there are large quantities of peat. Although they rarely succeed as garden plants, a sandy, acidic soil seems to suit them under cultivation. They can be propagated by fresh seed or root division. (*I attempted to grow Labrador tea once many years ago after acquiring it from a native plant specialist. It did not even make it through its first summer, I have to admit.) The common name derives from their history as a tea substitute, and they do indeed brew a nice cup of tea! Our aboriginal people much utilized this plant to make a cold infusion to treat rheumatism and arthritis. Labrador tea can be found across Canada and throughout Alaska and northern Europe.
The other two species are trapper’s tea (L. glandulosum) and L. palustre. The first is found in western North America, and grows 3-5 ft. It is distinctly aromatic but does not make near as a good a tea as L. groenlandicum. It also has larger flower clusters. L. palustre is from North America and Europe, and grows 1-4 ft tall and can be a spreading or erect evergreen shrub. The young shoots are covered in distinct, red-brown hairs and the flowers appear in late spring or early summer.
Kalmia- Named for Dr. Peter Kalm, a keen gardener and amateur botanist who explored the east coast of North America in the 1770’s. There are seven species found in this genus, all of which are North American but for one found in Cuba. Mostly evergreen, these are shrubs that are often cultivated for both their smooth, opposite leaves and stunning flowers. They do well in containers and require a slightly acidic, peaty soil and consistent moisture. Dappled shade, shelter from wind, and good drainage are also required, which is probably why they are not more common than they are. Often called bog laurels, these beautiful plants are pollinated chiefly by bees and can be propagated fairly easily from cuttings, although seed is also possible. (*Though exceedingly difficult.) Before planting one, you should be aware that all of these plants contain extremely toxic alkaloids called andromedotoxins, and symptoms do not appear until anywhere from three to 14 hours after consumption. These symptoms include intense watering and/or bleeding of the mouth, nose, and eyes, as well as headache, vomiting, weakness, and paralysis. This is usually followed by death. Sheep, goats, cattle, horses, and humans are all documented as having been killed by eating these plants. They are among the most poisonous plants found in this family.
Sheep laurel (K. angustifolia) is so named because of its well known toxicity to sheep. It can be found from Ontario into the maritimes and throughout the northeastern United States. Flowers range from rosy red through pink and are very showy. It is occasionally cultivated, and tolerates dryer soil than other species. It is hardy to zone 2, but quite difficult to establish.
Often called calico bush or mountain laurel, K. latifolia is native from eastern Canada south all the way to Mexico. It is a dense evergreen shrub with dark green leaves and grows as tall as 10 ft. Many cultivars have been developed, and it is the most widely planted species. A few of the better ones include:
‘Bull’s Eye’- 3-6. Ft. tall with bronzy new growth and white flowers marked with purple. Best in partial shade.
‘Little Linda’- 3 x 3. Red buds and pink blooms.
‘Elf’-3 x 3. Very small leaves, very compact and tidy. Light pink blooms marked with white.
‘Minuet’- 3 ft. Pink buds open to dark purple, very large blooms.
‘Pristine’- 3-4 ft. tall and wide. Very pure white flowers.
‘Olympic Fire’- 5 ft. Red buds and reddish pink flowers. Profuse bloomer and very showy.
The western swamp laurel (K. microphylla) is a low growing evergreen found right across Canada including the northern territories. It favors cool bogs, stream banks, and lake shores in alpine and sub-alpine zones. It has leathery, dark green leaves that are grey-white beneath, often with rolled margins. Flower color is variable but usually ranges from pink through deep rose. It is known to be fatal to both humans and livestock if eaten. Western swamp laurel was always sort of a botanical unicorn for me; an almost mythical thing seen in field guides and read about on the internet but never seen in real life. This last summer, while hiking in Kananaskis with my friend Jody, I saw and photographed it for the first time. (*Though both of these photos of it were taken by Jody. She has camera skills I do not have.) Since then, I have seen it on two other occasions. Finding a plant in the wild that you have only read about is one of those thrilling things that happens sometimes! I was struck each time I saw it by how specific it is about the conditions in which it chooses to grow. I was also reminded how fragile ecosystems are and how we have to be so careful about protecting them!
Gaultheria- Named for the Canadian botanist Jean-Francois Gaultier, this is a widespread genus of about 170 species, found in the Americas, Europe, Asia, and the south Pacific.
The best known species is Gaultheria procumbens, better known as wintergreen. In some areas, it is also called checkerberry or teaberry. An evergreen groundcover growing 3-6” tall, this species has glossy leaves and small white or pink flowers, followed by scarlet or pinkish red berries. These berries are large for the size of the plant and although they are not tasty to eat, they are the commercial source of methyl salicylate- better known as oil of wintergreen. Wintergreen oil is used to scent or flavor toothpaste, chewing gum, cigarettes, cough lozenges, and everything in between. Although slow growing, wintergreen makes a good groundcover for moist, acidic soil and does well in partial shade. It is also an excellent container plant and is often sold throughout Autumn and around Christmas time for use in seasonal planters. ‘Red Baron’ is a more compact cultivar that produces a significantly larger quantity of fruit than the species. Hardy to zone 4, wintergreen has done well in microclimates in zones 2 and 3.
Almost as well known as wintergreen, salal (G. shallon) will be familiar to anyone who has ever spent time on North America’s west coast. This is an evergreen, broadleaf shrub growing anywhere from 2-6 ft. tall and forming dense thickets. In full sun, it tends to be low and creeping. In shade it tends to be tall and erect. The cut branches are often used by florists for greenery and it makes an excellent groundcover in partly shady areas where other shrubs do not want to grow. A moist, acidic soil suits it best but salal is very adaptable and grows in a variety of situations. It is remarkably drought tolerant once established. The pink flowers of salal appear early and are much loved by hummingbirds; these are followed by edible, dark blue or purple berries. Reports vary widely as to the tastiness of salal berries- many people regard them as totally inedible and other people consider them a delicacy. They make excellent jams and jellies and were highly prized by the aboriginal peoples of what is now Oregon. Not only was it an important food plant, the berries were also used to create a beautiful purple to black dye. Zone 4.
Another species from the west coast is G. ovatifolia. This little charmer is a mat forming shrub with small, glossy leaves and pink or white blooms followed by red berries. The flowers have the most charming little red calyxes! It makes a good groundcover for a moist, shady area but can be difficult to establish. The berries are edible, but not delicious.
G. depressa is from New Zealand, and very common throughout the country in rocky or boggy ground. It is a wiry, low shrub growing about 4” tall with reddish stems and white or pale pink blooms followed by white to deep pink berries. Very similar but from Tasmania and southeast Australia is G. hispida, often called waxberry. It has white flowers and white berries. Neither of these species is considered edible.
If you were to wander into South America, you may find G. mucronata growing in Argentina and Chile. Highly variable and growing from 1.5- 5 ft. tall, this species has small green leaves, reddish stems, and white or pale pink blooms. The flowers are followed by very large, showy fruit that can be white, red, purple, or pink. It is often used for landscaping and the fruit lasts a long time, although it is not edible. Zone 5.
Alpine wintergreen (G. humifusa) is native to alpine and sub-alpine zones in the Rockies. It forms large mats of dark green, leathery leaves and is fairly common in BC, Idaho, and Montana. The flowers are usually pinkish or greenish white and give way to pulpy, scarlet berries that are edible but can cause digestive upset if eaten in large quantities.
Erica- The genus for which the family is named (Ericaceae), this lot is comprised of well over 750 species. It is a very diverse group of small evergreen shrubs native primarily to South Africa, although there are also species native to Madagascar, Europe, and the middle east. Commonly known as heathers, these little shrubs are among the easiest plants in this family to grow. They like moist, acidic soil with good drainage and generally prefer cool areas with low humidity. Leaves are usually needle-like and flowers are bell shaped, coming in many colors. Pink through white is common, but they come in almost every shade except blue. Sun to partial shade with plenty of nutrients suits them best, and they are quite easily propagated from cuttings. They are extremely popular for landscape use and there are several hundred hybrids as well. They tend to be short lived, but they flower profusely over a long period and many of them bloom in the winter months. Although many of them lack the hardiness to survive on the prairies, a number of them make excellent container specimens, especially for Autumn displays.
Erica cinerea is hardy to about zone 6. It is fast growing with deep violet flowers, growing about 12” tall and up to 36” wide. ‘Atropurpurea’ and ‘CD Eason’ are good cultivars. E. vagans is one of the hardier species, surviving to zone 4. It is native to the UK, Ireland, France, and Spain and is prized for its long period of bloom. Flowers are usually brilliant pink. ‘Mrs. DF Maxwell’ is a particularly compact and much loved cultivar. The snow heath (E. carnea) is also very hardy, hailing from the Swiss Alps, northwest Italy, the Balkans, and parts of eastern Europe. It is a small, low spreading shrub with purple to pink blooms and flowers from winter through spring. It would be worth trying in a sheltered location.
As you can imagine with so many species, there are lots of hybrids to choose from. Most hybrid heathers are listed as Erica x darleyensis, and some forms are better than others. ‘Kramer’s Red’ (which is actually pink) is very popular, as is ‘Mediterranean Pink’ and ‘Silver Bells’. The hybrids tend to be more tolerant of ordinary garden conditions, and they are often more vigorous than the species and flower longer and more profusely.
The hardiest of all the heathers is E. tetralix, the Swedish yellow heather. It is hardy to zone 3 with pink flowers and yellow-green foliage. It is, however, difficulto to cultivate. In addition to needing moist, acidic soil it needs cool temperatures and low humidity to thrive. It also requires good snow cover to prevent winter browning and is prone to root rot in heavy soils. Still, it is worth trying and good success with it has been had in Edmonton.
In addition to being beautiful, heathers produce significant quantities of nectar and are very attractive to foraging bees. Heather honey is highly prized.
Epigaea- There are three species in this genus, only one of which is cultivated, and then only rarely. Epigaea repens is commonly called mayflower or trailing arbutus, and it can be found from eastern Saskatchewan right through into the maritimes. It is an evergreen, scrambling shrub with long, leathery leaves and white or occasionally light pink, fragrant flowers. Flowers can appear anytime from February through May (depending on which zone it is growing in) and it is often the first shrub to flower in spring, heralding that the long winter is over. Generally found in acidic, sandy or rocky soil in clearings in wooded areas or the edges of meadows, this plant has found some degree of fame as it is the provincial flower of Nova Scotia. This has also led many people to want to try growing it in their gardens, but it is prone to transplant shock and often difficult to establish. Once very common, this shrub has severely declined in recent years due to extreme sensitivity to environmental changes. It has little tolerance for pollution and cannot handle windy or exposed sites. Picking of the blossoms for spring bouquets has also decreased its numbers, and climate change is also believed to have played a role in its decline. I have to say that in all honesty, I have never seen this plant in real life. If anyone knows a place where it is growing, would you please notify me? I would most dearly love to photograph and admire it in person.