Asarums As Companion Plants
North Vancouver, British Columbia Canada
Asarums, commonly known as the "wild ginger," are beautiful, low-growing perennial plants usually achieving a height no higher than 15 cm (6 in.) and often less. The plants spread by rhizomes forming an elegant and bold ground cover. There are about 10 species of asarums grown in gardens. They come from North America, Asia, and Europe. Botanists feel that there are more to be discovered in Asia.
The leaves of asarums are dark green, usually glabrous and leathery, often shiny with marbled markings. The flowers of asarums, although interesting, are insignificant to the overall beauty of the plant. Their colour is a dull green, brown, or a sort of purple-brown. The flowers are bell-shaped with three tail-like petals. These unusually shaped flowers grow at ground level and are hidden among the leaves. The fruit is a fleshy capsule which splits when ripe exposing numerous seeds.
I grew two asarums in my garden in Dartmouth, Nova Scotia, Asarum europaeum and Asarum hartwegii , and continue to grow them here on the West Coast. I grow both for their very handsome foliage. The leaves of A. hartwegii are heart-shaped, green and brushed with silver markings. At a quick glance one could mistake the leaves for those of a cyclamen. Some forms of A. hartwegii are better than others, and these superior plants should be propagated vegetatively. The leaves of A. europaeum are a very dark, glossy green with prominent veining patterns. The shape is blunt, and it has perhaps less substance than A. hartwegii . However, because the leaves are glossy, A. europaeum provides a light-reflecting, attractive pattern on the floor of a garden which A. hartwegii does not.
Drawing by Rosemary Read
The leaves of both plants stay green throughout the year in my garden. On the East Coast, in late March to early April, the old leaves would gradually wither away as the new leaves emerged. The plants bloomed in May and in very early June. Here on the West Coast, because of the earlier spring, the plants will begin moving somewhat earlier.
Two species of asarums that I have always planned on growing are A. canadense , an East Coast native, and A. caudatum , a West Coast native. I don't think either one measures up to A. hartwegii or A. europaeum , but they are still definitely worth a place in the garden. I have often wished that some of the Asian species were available to us, as I am sure there would be many beautiful garden plants among them.
Asarum canadense is hardy to Zone 2, A. europaeum and A. caudatum to Zone 4 and A. hartwegii to Zone 6. In the wild asarums grow in woodland soils making them a wonderful natural underplanting for rhododendrons. Although they spread by rhizomes, they are not rampant growers so there is not much worry about their becoming entangled with rhododendron roots. They are easy growers, only needing water in dry weather and a top dressing of fertilizer in the spring, much the same care one would give rhododendrons.
Asarums are easy to propagate from seed. In fact, self-sown seedlings are common, and I often transplant the seedlings to a nursery bed for future use. If you wish to collect the seeds, harvest them as soon as they are ripe. I discovered that the ants love the seeds and will carry them off as soon as the seed capsule splits open. It will take a couple of years for the seedlings to achieve a size suitable for planting in a rhododendron garden. Look to various plant societies as a source of seeds.
Large plants can be divided quite easily in late spring just after the new growth begins. Simply put a spade or two forks through the plant in the same manner one does to divide most perennials. I gave away many pieces from my original plants by doing this. Occasionally one can find a nursery that sells asarums.
Both the leaves and the rhizomes of asarums have a scent and a taste reminiscent of ginger, the reason for its common name. I have read that the early pioneers dried the root for use as a substitute for the true ginger.
Asarums are a beautiful companion plant for the rhododendron garden.
Carol Dancer, a member of the Vancouver Chapter, lived and gardened in Nova Scotia for over 12 years. She has lived in British Columbia for the past two years.