How to Grow and Care for Grey Willow

The grey willow, known botanically as Salix cinerea, is a fast-growing, deciduous shrub or small tree. It is often found in wet habitats and is recognized for its soft, fluffy catkins that emerge in the early spring, a feature that leads to its common name of “pussy willow”. This species can grow as a large, multi-stemmed bush or occasionally as a small tree, reaching heights between 10 and 33 feet. It is native to Europe and Western Asia.

Identifying the Grey Willow

A distinct feature for identifying the grey willow is its leaves. Unlike the long, slender leaves of many other willows, those of Salix cinerea are broadly oval or obovate, meaning they are wider above the middle. The leaves measure between two and four inches long, with a dull green upper surface and a pale, felted underside covered in soft, grey hairs.

Before the leaves appear in spring, the tree produces its catkins. Grey willow is dioecious, which means male and female flowers grow on separate plants. Male catkins are stout, oval, and silvery-grey at first, turning a yellow as they become ripe with pollen. The female catkins are longer, narrower, and greener in color.

The bark of a mature grey willow is grey-brown and develops diamond-shaped fissures and grooves as it ages. Younger twigs are often hairy and can show a red-yellow hue in the sun. Peeling back the bark on a two-year-old branch reveals a unique characteristic; the wood underneath will have prominent ridges or striations, which helps distinguish it from similar species like the goat willow.

Natural Habitat and Growing Conditions

The grey willow is native across a wide swath of Europe and Western Asia. Its natural habitats include fens, marshes, swamps, the edges of rivers and lakes, and damp woodlands. The species is highly tolerant of these conditions and can even grow partially submerged in water.

Grey willow performs best in locations that receive full sun to partial shade. While it is adaptable to a range of soil types, from acidic to slightly alkaline, consistent water availability is the determining factor for its successful growth.

This adaptability has allowed it to naturalize in various regions outside its native range. The plant’s preference for sunny, waterlogged locations means it quickly colonizes disturbed wetlands and riparian zones.

Role in the Ecosystem

In its native environment, the grey willow contributes to the local ecosystem. Its early-blooming catkins are a primary source of pollen and nectar for bees and other pollinators emerging in late winter and early spring. This makes the plant a food resource for supporting pollinator populations when few other flowers are available.

The foliage of the grey willow serves as a food source for the caterpillars of several moth species, including the sallow kitten and lunar hornet clearwing. It is also a food plant for the purple emperor butterfly. The dense, thicket-forming habit of the shrub provides shelter and nesting sites for various birds, such as chiffchaffs and long-tailed tits, as well as small mammals.

The grey willow’s extensive root system stabilizes the soil on riverbanks and floodplains, which helps to reduce erosion. The plant’s ability to absorb excess nutrients from the soil can also assist in filtering water. Its presence near water makes it a hub for aquatic insects and amphibians.

Potential Issues and Considerations

A primary issue with the grey willow is its status as an invasive species in many regions outside its native range. In countries like New Zealand, Australia, and parts of North America, it is classified as a noxious weed. The plant was often introduced for erosion control, but it has since escaped cultivation and threatens native wetland and riparian environments. It grows into dense, impenetrable thickets that outcompete and displace native vegetation.

These thickets can also alter the hydrology of waterways. By forming dense stands, they can block water flow, which may contribute to flooding and changes in river channel structure. Grey willow readily hybridizes with native willow species, posing a threat to their genetic integrity. Its prolific seed production and ability to resprout from fragments contribute to its rapid spread in invaded habitats.

From a structural standpoint, like many willows, its wood is somewhat brittle and can be susceptible to damage from high winds or heavy snow. It is also affected by common pests and diseases such as aphids, canker, and rust fungi.