Weeping Pussy Willow (Salix caprea)

Goat willow (Salix caprea) is a small deciduous tree or large shrub also known as pussy willow. Goat willow is native to Europe and western and central Asia. This species is not considered a good source of timber, as its wood is brittle. Salix caprea means “goat.” This species is susceptible to disease mediated by insects and microbes.

I. Appearance and Characteristics

Salix caprea, known as goat willow, pussy willow or great sallow, is a common species of willow native to Europe and western and central Asia.

The Latin specific epithet caprea means “goat”. This, and the common name goat willow, probably derive from the first known illustration of the species in Hieronymus Bock’s 1546 Herbal, where the plant is shown being browsed by a goat. The species was historically also widely used as a browse for goats, to which Bock’s illustration may refer.

It is a deciduous shrub or small tree, reaching a height of 8–10 m (26–33 ft), rarely to 13 m.

The leaves are 3–12 cm long and from 2–8 cm wide, broader than most other willows.

The flowers are soft silky, and silvery 3-7-cm-long catkins are produced in early spring before the new leaves appear; the male and female catkins are on different plants (dioecious). The male catkins mature yellow at pollen release, the female catkins mature pale green.

The fruit is a small capsule 5–10 mm long containing numerous minute seeds embedded in fine, cottony hairs. The seeds are very small (about 0.2 mm) with the fine hairs aiding dispersal; they require bare soil to germinate.

The two varieties are:

• S. c. var. caprea – lowland regions throughout the range, leaves thinly hairy above, densely hairy below, 5–12 cm long, stipules persistent until autumn
• S. c. var. sphacelata (Sm.) Wahlenb. (syn. S. caprea var. coaetanea Hartm.; S. coaetanea (Hartm.) Floderus) – high altitudes in the mountains of central and northern Europe (Alps, Carpathians, Scotland, Scandinavia), leaves densely silky-hairy on both sides, 3–7 cm long, stipules early deciduous. In western Norway there are trees of S. c. var ‘Sphacelata’ that are 18–20 meters tall and have mostly single trunks.

II. How to Grow and Care

Sunlight

The goat willow likes light; full sun is conducive to the photosynthesis of its leaves. The best foliage color appears when there is plenty of light, so plant it in an open spot in the garden that ensures at least 6 hours of sunlight per day. However, it will also grow well in partial shade.

Temperature

The goat willow grows better in a temperate environment, but can tolerate both high and low temperatures. It prefers damp areas, but does have both flooding and drought tolerance. It grows best in a temperate range of 15 to 25 ℃, but can withstand low temperature conditions of about -46 ℃.

The goat willow mostly grows in wetlands beside the banks of rivers. Short-term flooding will not lead to its death. The goat willow is also often planted in water tanks or vases indoors, but it needs to be regularly provided with appropriate amounts of nutrient solution to meet the necessary nutrient requirements for growth. At the same time, any impurities should be limited as much as possible, and the pH of the water should be alkalescent to avoid the plant blackening and spoiling.

Watering

Goat willow thrives in moist environments, echoing its native habitat’s high humidity levels. This species exhibits a preference for consistent moisture but is also known for its moderate drought tolerance once established. Watering should be done once every three weeks to maintain its hydration needs without over-saturating the soil. As goat willow is predominantly an outdoor plant, it’s important to consider how natural rainfall contributes to its watering schedule, especially since it can influence the dormancy period and overall water uptake of this deciduous species.

Soil

The goat willow is a highly adaptable plant with low soil requirements. Although it prefers moisture-retentive soils, it will grow well in a variety of soil types, and isn’t fussy about pH. Good drainage is important in clay soil, otherwise the roots may rot, so pay attention to this during the plant’s growth period.

Fertilizing

For optimal health, goat willow benefits from balanced nutrition fertilizers to support robust growth. Apply a balanced NPK formulation in early spring, just as growth resumes, and optionally, again in late summer to prep for dormancy, using dosages as per package instructions. Fertilization enriches soil nutrients, encouraging vigorous growth and prolific catkin production. Seasonal changes determine fertilizing frequency; less is needed during dormant periods. Use fertilizer sparingly to avoid root burn. Practical tip: Water goat willow thoroughly post-fertilization to aid in nutrient absorption.

Pruning

Goat willow can be coppiced (trimmed off at ground level) without any problem. Cutting them right back to the ground every few years can stimulate good regrowth and usually results in larger catkins and longer stems developing. This tolerance for frequent hard pruning makes goat willow a viable plant for hedges. If you plan to trim the tree, make sure you do this immediately after the blooming season. The catkins form on the previous season’s wood, and you don’t want to risk diminishing next year’s display by pruning too late.

Propagation

While most species of willows are extremely easy to propagate simply by planting a branch cutting directly in the soil, goat willow is slightly more temperamental as regards this method, and therefore is more often propagated by seeds (see below).

Rooting stem cuttings can be successful, but you may need to plant several cuttings to ensure success with at least one. Here’s how:

• During active growth in spring, cut a new, reasonably thick branch that has at least a couple of buds higher up on the cutting.
• Dip the cutting in rooting hormone, and plant it about 6 inches deep in the desired garden location.
• Keep the cutting well watered. Within a few weeks, the cutting may develop rots and begin producing new growth.
• You can use the same technique to start cuttings in containers filled with potting mix.

How to Grow From Seed

Goat willow is a dioecious plant, with plants having either male or female catkins, but not both. Therefore, if you want fertile seeds, you’ll need to have a female plant as well as a male plant somewhere in the near vicinity.

In mid-spring when the catkins have a cottony appearance, harvest some catkins from a female plant (these catkins will have a greenish color) and break them apart to separate the seeds. Immediately sow the seeds on the surface of small containers or a seedling flat filled with standard potting mix, with the silky seed hairs still attached. Keep the seeds likely moist until they germinate and sprout. The seedlings grow very quickly, so they can be transplanted into their permanent garden locations within a few weeks.

Do not attempt to store goat willow seeds, as they will quickly lose their viability if not planted immediately.

Potting and Repotting

Goat willow grows fast and gets large rather quickly, so it’s not often grown in containers, except for starting stem cuttings. The weeping variety (Salix caprea ‘Pendula’) is a somewhat smaller plant, however, so it is sometimes grown in large, deep, heavy pots that can resist tipping. A potted goat willow will need an extremely moisture-retentive potting mix, such as a mixture of commercial potting mix blended with compost. Be prepared to water potted willows very frequently. A potted goat willow may also benefit from a fertilizer applied annually in the spring.

Overwintering

Goat willows grown as garden specimens generally don’t require any special winter treatment. If you are growing one as a potted plant, however, it will need some protection against the cold. Moving it to an unheated garage or porch is a good method. Or, the pot can be moved to a sheltered location and wrapped with insulation or heaped with compost for the winter.

Pests and Diseases

Common Pests and Plant Diseases

Although the tree is hardy, goat willow is susceptible to several diseases, including powdery mildew, twig and leaf blight, and leaf spot. Willow anthracnose is a more serious fungal disease that can cause complete defoliation of the plant after initially causing black spots and distorted growth. It is a hard disease to cure, but removing affected branches and cleaning up leaf debris can keep anthracnose from spreading to the entire plant.

Aphids and caterpillars are drawn to the leaves of this plant. Hard water spray will dislodge these pests; or, you can spray the plant with horticultural oil.

Common Problems

Goat willow is very easy to grow, but the wood is brittle and subject to breakage from heavy snows or ice storms. Fortunately, damaged branches are easily cut out, and heavy pruning only stimulates new growth.

In its eagerness to reach moisture, the roots of goat willow have been known to damage underground water pipes or sewer lines and can clog drain lines. It is best planted many feet away from such utilities.

III. Uses and Benefits

• Ornamental uses

The silky, grey-colored catkins that are produced in the spring by goat willow have long been admired, with this tree planted for ornamental purposes in parks, woodland areas, and wildlife gardens. This tree will flourish in moist ground, tolerating saturated soil, so planting alongside ponds and streams is not an issue. It is prized for being low maintenance and is excellent as a windbreaker or screen.

• Cosmetic uses

A small number of cultivars have been selected for garden use. The most common is S. caprea ‘Kilmarnock’, discovered by James Smith, with stiffly pendulous shoots forming a mop-head; it is a male clone. A similar female clone is S. caprea ‘Weeping Sally’. As they do not form a leader, they are grafted on erect stems of other willows; the height of these cultivars is determined by the height at which the graft is made. Plants can also be grown from greenwood cuttings, which make attractive creeping mounds. Hardwood cuttings are often difficult to root.

Both tannin and salicin can be extracted from goat willow bark. The tree is not considered a good source of timber, as its wood is both brittle and known to crackle violently if burned.

As with the closely related Salix discolor (American pussy willow), it is also often grown for cut flowers.

In Scandinavia it has been fairly common to make willow flutes from goat willow cuttings.

In Germany, Hungary, north of Slovakia, Poland and Ukraine, the just-opened catkins are used like the olive branches on Palm Sunday.