Willowy: abounding with willows; resembling a willow; pliant, flexible, gracefully tall and slender (Merriam-Webster)
How many plants have so infiltrated our collective mind that they describe not only the plant, but also characteristics of people? Oaks come to mind, as in, strong as an…but few others. Willows have been used by people for eons, in craft, furniture and medicine, so its presence in our language is understandable.
Below are descriptions of just a smattering of the 200-plus species of Willows in cultivation, types that are reliably found at Portland Nursery each spring. Many more exist and may make their way into our rotation if we are lucky. Several species native to the Pacific Northwest, Western Willow (Salix hookeriana) and Sitka Willow (Salix sitchensis) are often part of our Native Trees selection.
'Golden Curls' - S. alba 'Tristis' x S. matsudana 'Tortuosa) – Gold twisting branches & curly green leaves that turn gold before falling off in autumn. Grows as a large multi-stemmed shrub or is trained into a tree form. Portland Nursery carries the tree form. Grows 30' x 15', Sun, Z5 (-20f)
'Red Curls' - S. matsudana 'Tortuosa' x S. alba 'Britzensis' – Curly mahogany red stems and twisting green leaves. Grows as a large multi-stemmed shrub or is trained into a tree form. Portland Nursery carries the multi-stemmed form.
Grows 30' x 15-20', Sun, Z5 (-20f).
Golden Weeping Willow or Niobe Willow- Salix alba 'Tristis' – One of the hardiest and largest Weeping Willows. Its trunk and main branches grow upright, while gold-barked side branches weep straight to the ground. Stem color is most prominent during winter. Leaves are bright green, narrow & lance-shaped. Flowers occur in catkins.
Grows 50-70' tall, 30-50' wide, Sun, Z4 (-30f)
Babylon Weeping Willow - Salix babylonica – Weeping Willow with stout upright branching structure and side-branches that hang to the ground. Bark is reddish-brown when young and leaves are bright green on top and milky green beneath, turning gold before falling in autumn. Flowers occur in fuzzy catkins that are obscured by foliage.
Grows 30-40' x 30-40', Sun, Z6 (-10f)
French Pussy Willow or Goat Willow - Salix caprea – Late in winter, fuzzy gray catkins push through bronze buds to hale the coming of spring. Round simple green leaves to 4" long have fuzzy backing & turn gold to brown before falling in autumn. Pussy Willows usually grow as a multi-stemmed small tree or large shrub. They can be cut low to the ground after bloom to maintain a smaller size.
Grows 15-30' tall x 12-15' wide if unpruned, Sun, Z4 (-30f)
Weeping Pussy Willow - Salix caprea 'Pendula' – This Pussy Willow has the same flowering and leaf characteristics as the species, S. caprea. Instead of growing upright though, it stays low, growing along the ground like a groundcover. When grafted to a trunk, the Weeping Pussy Willow forms a small mounded canopy and weeps to the ground. Best with regular water in summer.
Full size is 8-10' tall x 6-8' wide, Sun, Z4 (-30f)
Creeping Alpine Willow - Salix yezo-alpina – White fuzzy catkins 2" long come at the same time as leaves in late March. Leaves are green, leathery and covered in a thick white pelt of fuzz. The Alpine Willow creeps slowly along the ground, mounding here and there, but mostly spreading out. Best with regular moisture in summer months. Very nice for use in rockery or in a container where it can spill over the side. Grows 6-8 inches tall x 3-4 feet wide, Sun-part shade, Z5 (-20f)
Dappled Willow - Salix integra 'Hakuro Nishiki'
This Willow is grown mostly for its leaves. In early spring leaves are subdued, barely showing a hint of what is to come, with a bit of white speckling amongst the light green color. The next thing you know, leaves so white and pink they look like flowers have covered the plant. This stage lasts until the heat of summer arrives and fades foliage to 'dappled' green and white. New branches grown during spring maintain a bright coral pink color year round. Older bark tends to fade to light brown.
White and pink leaves have less chlorophyll than green leaves, so they burn in hot sun. They have the best color when planted in a spot with a few hours of morning sun and shade for the remainder of the day.
Dappled Willow can be cut low to the ground in early spring to keep the plant bushy and promote good leaf and stem color, or it can be allowed to grow into a more open & large shape.
Grows 3-4' x 3-4' if pruned low in spring, 5-6' x 6-8' unpruned.
Part Shade – Shade, Z5(-20f)
Dwarf Arctic Willow, Dwarf Purple Osier - Salix purpurea 'Nana' – Slender blue-green leaves turn gold in autumn, dark purple stems sway in the breeze. Like many willows, the Arctic Willow can be either pruned close the ground to keep it smaller, or allowed to grow larger and develop a more open branching structure.
Grows 3-4' if pruned low to the ground, 5-7' unpruned. Sun, part shade, Z3 (-40f)
Genus: Salix (SAY-licks) based in Celtic, sel means 'near' and lis means 'water'.
Origin: Salix is found all over the world, except in Australia.
Characteristics: There are around 250-300 species of willow shrubs and trees. Almost all lose their leaves in winter, and most bloom before or with the first leaf set in spring. Flowers are set in tight clusters called catkins, some of which are covered in fuzz (Pussy Willows).
Many have yellow, red or purple bark during the cold of winter. Typically willows develop a dense fibrous root system that searches out water, so they should be planted well away from the foundation of a house, and away from water lines.
Size: Willows range from 6" x 24" shrubby groundcovers to 70' x 50' trees depending on species.
Light: Most prefer full sun to part shade. Willows with white or pink leaves (Dappled Willow) should be shaded during the heat of the afternoon.
Culture: Willows generally grow quickly, both in the root system and above ground. They have a natural affinity for water and in nature are found growing along stream banks, lakes and rivers. They like moist soil but can adapt to drier areas once their roots are established. Because of their dense root system, it can be difficult to grow plants around or underneath willows.
Pruning: Willows tend to accept pruning very well and grow back quickly. Many willows have branches that are used for decoration, basket weaving, twig furniture and wattle fencing.
- • Shrubby willows (Dappled, Arctic & Pussy Willows) can be pruned low to the ground (coppiced) to keep them smaller and to promote better stem & foliage color.
- • Pruning can happen at any time during the year, but keep in mind that when branches are cut, new growth is stimulated.
- • Willow trees will accept pruning, but should be planted in an area where they have enough room so the minimal pruning is needed. Trees that are over-pruned are more susceptible to diseases like Crown Gall.
Hardiness: varies by species – some as cold tolerant as Zone 2 (-50f). Many species are suited to Portland.
Problems: Willows are prone to many pests and diseases.
Fungal & bacterial diseases - Twig blight, leaf blight, canker, crown gall, anthracnose, scab, mildew, rust… follow this link for disease photos & solutions.
- • Insects - aphids, willow leaf beetle, borers, lace bug, sawfly, thrips – aphids are the most common in our climate and are among the easier insects to treat.
- • Breakage - Because they grow so quickly, willow branches are weak and break easily, especially under snow or ice and during wind storms. This is another good reason to plant willow trees at least 20' from the house.