The female catkins have longer green catkins. These flowering branches, among the first that appear in spring, are often harvested for decorative use. S. caprea is one of two species commonly known as pussy willow, and it is easily confused with the native North American species, Salix discolor. Goat willow is extremely easy to grow and tolerant of heavy pruning, and it is extremely attractive to many species of butterflies and bees. Goat willow is generally planted from nursery-grown potted plants in the early spring. It is a fast-growing but relatively short-lived shrub or tree, typically living 15 to 30 years. This tree has long, deep and creeping roots that seek moisture. You’ll need to be mindful about where you plant it, as it is often known to disrupt water and sewer lines.
Light
This tree prefers to receive plenty of sun (six-plus hours each day), although it can tolerate a partial shade position.
Soil
Goat willow will grow in most soil types but has a preference for damp soil. It is one of those few species that actually prefers dense, poorly drained soil. It can tolerate dry and sandy conditions too, although mulching around the base of the tree can be beneficial in these situations.
Water
Goat willow is a water lover, thriving in areas that have moist, even wet conditions. It does well in wetlands and bogs and is a great choice for gardens that have poor drainage. Goat willow is also relatively tolerant of short droughts, though growth can be stunted under these conditions
Temperature and Humidity
Hardy in USDA zones 4 to 8, this plant prefers a temperate, mild summer and can handle cold winters with ease. Extreme and prolonged freezing conditions can cause branches to weaken and crack, but the damage is easily pruned out and doesn’t cause lasting damage to the plant. In very hot regions, the growth rate of goat willow is usually considerably slower. Humid conditions may make goat willow somewhat more prone to fungal diseases.
Fertilizer
Unless you’re growing goat willow in a container, you won’t need to fertilize the plant. Its spreading roots help it to find the nourishment it needs. One exception is if you want to grow the plant for the purpose of harvesting the young stems in the spring when they are covered with catkins. If this is your goal, it’s best to cut the plant down to ground level and fertilize heavily each spring.
Types of Goat Willow
Salix caprea is often sold in its pure species form, but there is one cultivar, ‘Pendula’, which has a weeping form and smaller stature that makes it good for container culture. There is also a pair of male and female clones with a weeping habit, marketed as ‘Kilmarnack’ and ‘Weeping Sally’, respectively. These are grafted plants. Salix caprea also hybridizes very easily, and many naturalized plants growing in the wild are hybrids, such as crosses between Salix caprea and Salix discolor, the native North American pussy willow.
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.
Propagating Goat Willow
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: You can use the same technique to start cuttings in containers filled with potting mix.
How to Grow Goat Willow 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
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.
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.
How to Get Goat Willow to Bloom
There’s generally no problem getting goat willow to bloom in early spring before the leaves appear, provided it is growing in a sunny spot and getting plenty of moisture. But if you want the attractive yellow color of the catkins, you’ll need to grow a male specimen, as it is the pollen that produces the yellow hue that is in such demand for decorative uses. Female plants have greenish catkins that are considered less attractive.
Common Problems With Goat Willow
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.
Goat willow is also a good plant for those who want to attract butterflies and bees.
