Never reaching more 2,000 m, the Appalachians extend from the Mississippi floodplain to the Gaspé Peninsula. In Quebec, the harsh climate has allowed alpine plants to flourish at certain levels on mid-range peaks like the Chic-Chocs, rising to 1,268 m. There one finds mostly Arctic-alpine plants, named for their boreal or mountain origins.
Plant life in the Rockies, where the peaks top 4,400 m, depends on both altitude and latitude. Alpine plants that grow above 3,300 m in Colorado are found at 1,200 m in the Yukon, with its colder climate. Glaciers carried many plants from the Arctic to this region: the Rockies are an important migratory route with very few endemic species. Mountain avens, lewisias and townsendias are some of the loveliest plants in these mountains, growing alongside a number of species from the Andean cordillera, including Acaena magellanica.
Extending across the far north of Europe, Asia and North America, the Arctic tundra covers a vast region that includes many islands. In this harsh climate, circumboreal plants grow at sea level and low altitudes, in conditions identical to those found high in the mountains in temperate zones. Fleeing the cold during the Ice Age, some Arctic plants spread southward and took root in the mountains. For instance, alpine meadowrue, a common boreal plant, is also found in the Alps at altitudes above 2,000 m.
Stretching for more than 1,000 km from the Mediterranean in France to the Danube in Austria, the Alps include the highest peaks in Europe, among them Mont Blanc, at 4,810 m. The first studies of mountain plants were conducted there in the mid-16th century, and they were again the focus of interest when alpine botany became popular two hundred years later.
The Alps are the kingdom of gentians, pinks and sea hollies, and edelweiss is their king. In the centre of its starry crown of woolly, white leaves rest the tiny flowers. Who would imagine that these miniature blossoms are the stuff of legend!
The Pyrenees, which form a mountainous barrier between France and Spain, are home to a vast number of alpine species, including roof houseleek, dragon mouth and stemless gentian. With their tiny fleshy, downy, waxy or spiny leaves held tightly together in a rosette or cushion, alpine plants have developed a variety of features that protect them from the cold and from dehydration. They often form dense moisture-retaining carpets, hugging the ground to shelter themselves from the wind.
The Carpathians and the Balkans
Like other mountains around the globe, the Carpathians and Balkans offer alpine plants a growing season lasting no more than three months. This has forced the plants to adapt in order to complete their reproductive cycle: small pasque flower forms floral buds in fall that over-winter underground. Under the snowy mantle, lifelong saxifrage, like many other species, continues to grow: it accumulates large quantities of soluble sugars through photosynthesis; they act like antifreeze and prompt the plant to produce masses of vividly coloured blooms in early spring.
From the Black Sea to the Caspian Sea, the Caucasus is ablaze in spring with the blooms of alpine plants growing at altitudes over 3,000 m. As soon as the days turn warm, the alpine meadows are filled with multicoloured, sweet-smelling and nectar-bearing flowers, attracting hoards of flying insects in search of mates: butterflies, honeybees, bumblebees and other nectar-loving winged creatures are all welcome. Sea holly, with its umbels bursting with nectar, is particularly appealing to bees. And fritillary lasts only long enough to flower, disappearing in summer as soon as its bloom fades.
Spread out under the “roof of the world,” with peaks rising to 8,848 m, Asia encompasses the largest alpine region on the planet. From the Caucasus to Japan, the Asian mountains are home to a wide range of habitats. Whether they prefer limestone or siliceous soil, sunny or shaded mountain slopes, Asian alpine plants are remarkable for their incredible diversity. While drumstick primula and spotted bellflower prefer alpine meadows, mukdénia grows on moist cliffs and sarmentous rock jasmine forms colonies on scree, thanks to its deep roots that spread widely near the surface and stabilize the soil.
Ground covers are low-growing perennials that for a sufficiently dense cover to hold earth on a bank or prevent the rapid growth of grass and weeds. They fill a wide variety of needs in the garden. They can be substituted for lawns where grasses will not thrive because of steep slopes, poor soil, or dense shade. They are used to accent, blend, and unify the other elements of the home garden. Hence, ground covers are chosen according to the site and ornamental value. Herbaceous plants such as rock cress and thyme are suitable on sunny, gentle slopes of small extent; goutweed and bugle are suitable for similar sites in shade.
Ground covers are usually hardy and resistant to diseases and insects. Choosing the right plant for a given use is generally the most important problem.
Growing plants in troughs started in England in the 20th century, when gardeners discovered old barnyard livestock troughs and thought of using these stone containers as planters.
Forming miniature gardens within a garden, troughs have become very popular. They come in various sizes and shapes and may be manufactured, made at home or assembled from natural or carved stones. Slow-growing, low-maintenance alpine plants are ideal for growing in troughs.
The Crevice Gardens
Crevice gardens recreate the natural habitat of eroded cliffs, providing excellent drainage and a wide range of growing conditions and making it possible to grow alpine plants that are better adapted to cool mountain air in a climate with often very hot summers. Although such gardens originated in England, they were popularized by Czech explorers and botanists, first in Europe and then in North America.
The first Crevice Garden was created in April 2002 under the direction of Josef Halda, a renowned botanist from the Czech Republic, in co-operation with the Quebec Alpine and Rock Garden Society. This garden is situated to the right of the entrance to the Alpine Garden in front of the pine trees.
Rocky peaks and eroded cliffs are recreated on a small scale, making it possible to grow here in Montréal high-altitude species that had never before been part of the Alpine Garden. According to Mr. Halda’s design, the rocks are arranged in a series of sloping layers, forming crevices in which the plants’ roots are able to anchor deeply and find the cool temperatures and moisture they need. The crevices also ensure optimal drainage. This Crevice Garden, created at the Montréal Botanical Garden in 2002, was the first of its kind in a public garden in Quebec at the time. This makes it a testing ground for new species and cultivars.
In the fall of 2004, the Montréal Botanical Garden welcomed a second specialist from the Czech Republic, Zdenek Zvolanek, designer of the Vertical Crevice Garden. The visitor is greeted by this second type of crevice garden upon entering the Alpine Garden. The designer intended to imitate cliffs with stratified rock faces upthrust by movements in the earth’s crust. The deep cracks ensure excellent drainage and keep the soil temperature and moisture constant for the alpine plants’ roots. The east-west orientation of the rocks and the uneven surfaces create pockets of shade and keep the plants as cool as possible.
This vertical crevice garden is the first of its kind in Canada and one of the world’s largest. It contains alpine plants from North America, Europe and Asia, including a number of saxifrage cultivars created by the late H. Lincoln Foster, a renowned American hybridizer to whom the garden is dedicated.