Ask a gardening friend about willows and he or she will likely recall the large weeping types and all their charming if often dubious qualities. Though unquestionably graceful and picturesque at the edges of ponds and streams, these trees can grow over 70 feet tall and are notoriously weak-wooded and messy. The reputation of their moisture-seeking roots for breaching pipes and the foundations of houses is also, unfortunately, too true.
Look beyond these giants, however, and you'll find another world of smaller, more manageable willows with brightly colored stems and leaves, unique forms and textures, and stunning catkins (the "pussies" of pussy willows).
If you've ever bought cut pussy willow stems from a florist to brighten the house in winter, you might enjoy growing your own for cutting at will. The catkins appear in late winter or very early spring and are easily forced into earlier bloom if brought into a warm house. And the color range is surprising: the catkins range from typical silver gray to soft pink. Some are even ebony black.
My own introduction to willows was born of laziness. I figured it would be a lot easier to choose plants that would thrive in the low, damp areas of my property than to raise or drain those areas. And because my garden is just 1/3 acre, I wanted plantings that would mature no larger than large shrubs or small trees. While I was thinking of willows primarily as a solution to planting in wet soil, I discovered many small tree and shrub forms that deserve a place of honor in the garden.
Willow flowers are tiny and come clustered in catkins. All willows are dioecious, meaning individual plants have either all-male or all-female catkins. The male catkins are usually finer-textured, and with their colorful stamens, are also much more ornamental.
Florist's pussy willow (Salix caprea), also known as French, goat, or pink willow; USDA Hardiness Zones 4 through 8. The large gray catkins gradually yellow as they mature. Their appearance in late winter before the leaves is a cheering sight. Without pruning, these willows grow to 20 feet or more. They tolerate dry soil. 'Weeping Sally' is a graceful, pendulous form with arching branches, usually grafted to reach 6 to 8 feet in height; it looks lovely beside a small pond.
Japanese pussy willow (S. chaenomeloides), also called quince-leafed pussy willow; zones 5 through 8. This recent introduction is one of the best for winter cutting. Ray Prag, owner of Forestfarm nursery in Oregon, who grows more than 70 kinds of willows, says this one has the biggest catkins, up to 2-1/2 inches long. They're silvery gray and take on a pink cast as they age. Equally significant, their bare winter stems are a rich mahogany red.
This willow was brought here from Korea in the 1980s by plant explorer Barry Yinger. It grows fast, to 20 feet in three years if left unpruned. Plant it where it has room and prune heavily in late winter before leaves emerge. Even when cut back annually, it often produces up to 9-foot stems!
Black pussy willow (S. gracilistyla melanostachys); zones 5 through 8. The anthers on the nearly black catkins turn yellow, producing a striking show that goes on for weeks. It is very finely branched, usually all the way to the ground, and never throws long simple stems like most pussy willows. This makes it impossible to display them in the same way. Instead, use fewer, shorter stems, perhaps mixed with other plants. Or use short, 8-inch sections in small vases. Leaves turn yellow before dropping, very late. Girth equals height, usually 6 to 10 feet. Considering its bronze-purple winter stems, this plant has little "down time." Maintain black pussy willow with aggressive annual pruning as soon as catkins begin to drop and leaves are emerging.
Corkscrew willow (S. matsudana 'Tortuosa'), also called dragon's claw willow; zones 5 through 7. The branches of this 20- to 30-foot tree twist and turn every which way, and its catkins are prominent. Overall, this is one of the best for indoor decoration.
Fantail willow (S. udensis 'Sekka'; formerly S. sachalinensis 'Sekka'); zones 5 through 7. Its unusual twisted stems are broad and flattened at their ends, a genetic condition botanists know as fasciation. Look for a plant with a lot of these branches, as some plants are more heavily fasciated than others. The small, silvery catkins mature to a soft yellow, and are very numerous. I counted 50 clustered along 30 inches of branch. The long, dark green leaves turn yellow in fall, and the supple branches sway in every breeze.
The best time to cut branches for forcing is when the catkin buds are just beginning to swell. It will take 2 to 4 weeks from bringing the branches indoors before the catkins emerge.
With a sharp knife, scrape off 2 inches of bark above where the branch was cut and lightly crush the scraped area. This helps the branch take up water. Arrange the branches in an attractive deep container of room-temperature water and place in bright light.
Willows are not fussy plants. All prefer full sun, but most tolerate some shade. They uniformly prefer wet, even soggy soils, but most adapt just fine to dry soils, though supplemental irrigation may be required. Some, such as S. caprea, thrive in relatively barren soil and also tolerate salty seaside conditions. All willows are fast growing and short-lived, and their wood is notably weak and prone to breaking.
Occasionally, aphids, scale, and Japanese beetles are a problem, and powdery mildew and rust diseases also sometimes appear. In every case but the Japanese beetles, pruning to the ground in spring after flowering reduces or eliminates the pest. Even normal pruning will usually rejuvenate the plant. "Willows are so vigorous that these [pests and diseases] will rarely kill the plant," says Ray Prag.
Most willows need pruning for two reasons: to maintain a convenient size and to stimulate growth of long stems for cutting. Heavy pruning (all the way to the ground) also stimulates more vigorous growth, which results in larger catkins. However desirable for the above reasons, heavy annual pruning may also produce a somewhat rangy-looking plant. If your willow is positioned in a prominent location, so that appearance is important, prune out a third of the oldest wood each year. Older wood is more susceptible to disease and pest problems. Prune just before the leaves come out, in late winter or early spring.
It's easy to propagate willows by cuttings. Start with an 8-inch leafless section of stem in spring. Plant it in a 4-inch pot filled with moist potting soil, then place it in a cool, shaded location. As soon as roots emerge from the pot's drainage hole, plant it in a permanent location or transplant to a larger container. Alternatively, you can plant willow cuttings directly in the ground in spring.
Patricia Acton writes and gardens by the Chesapeake Bay in Maryland.
Photography by Kate Jerome
Article published on June 23, 2008.