Willows are among the easiest trees in Britain to recognise and among the hardest to choose between. Most people picture the golden weeping willow leaning over a lake — lovely, but a 15–20 m tree with a spread to match and roots that go searching for water. The genus Salix runs from that giant down to the dwarf willow of Scottish hilltops, which barely clears your boot. Somewhere in between sit dozens of garden-worthy shrubs and small trees, several of which will behave themselves in an ordinary plot.
The big weepers: drama for a large garden
Two willows dominate the weeping market. Salix × sepulcralis 'Chrysocoma', the golden weeping willow, has yellow-green young shoots and fine, cascading foliage. Salix alba 'Tristis', the weeping white willow, is a little more upright, with silvered leaves, and is just as large.
Both want an open site — a pond edge, a field boundary, a big lawn. Moisture helps, though neither insists on boggy ground. What they do insist on is distance. Give them at least eight to ten metres from a house, garage, drain or soakaway, and more if you garden on heavy clay that shrinks in dry summers. A weeping willow planted three metres from a patio will cause trouble within a decade.
Dwarf and compact willows for small gardens
This is where willows earn their place on a modern plot. Height, habit and soil needs vary considerably, so pick for your conditions rather than for looks alone.
- Salix caprea 'Kilmarnock' — a grafted standard, roughly 1.5–2.5 m, with a stiff weeping head and fat grey catkins in early spring. Superb in a pot or at the front of a border. It needs cutting back each year after flowering, or the head reverts to bushy growth.
- Salix purpurea 'Nana' — a rounded dwarf purple willow, about 1–1.5 m, with blue-grey leaves and silvery catkins. Tolerates most soils, including drier ones, and makes a useful low hedge. Coppice it every few years to keep it dense.
- Salix repens — creeping willow, a British native of dunes and heaths. It spreads to form a low mat of 30–50 cm, with silvery catkins in spring. Ideal for sandy, free-draining ground and gravel gardens; it sulks in wet clay.
- Salix lanata — woolly willow, with soft silver-grey rounded leaves on a shrub of about a metre. It needs sharp drainage and full sun, so treat it as a rock-garden plant. Wet, heavy soil will finish it off in a season.
- Salix boydii — tiny, slow and neat, best in a trough or on a scree bed with lime-rich, gritty soil. Not a plant for an ordinary border.
- Salix herbacea — the dwarf willow, only a few centimetres high. It needs cool, moist, peaty ground and is realistically a plant for upland gardens or a specialist trough.
Contorted willows: twisted stems for winter interest
These are grown for their shape as much as their leaves. Salix babylonica var. pekinensis 'Tortuosa' — still widely sold as Salix matsudana 'Tortuosa' — is the corkscrew willow, with curled leaves and a tangle of twisted branches. Left alone it will reach around 8 m, but most gardeners coppice it every year or two and use the cut stems in arrangements.
Salix × sepulcralis 'Erythroflexuosa', the curly golden willow, is more compact and arguably the better garden plant. The young stems glow orange-red through winter, and it can be grown as a shrub, cut hard to the ground each spring. It is vigorous, so give it room to throw up its whips.
Soil, site and root considerations
Willows are thirsty, fast-growing and unfussy about fertility. Most will grow in clay, loam or sand, in acid or alkaline ground, as long as they are not sitting in stagnant water. Match the exceptions carefully:
- Damp or periodically flooded ground: weeping willows, Salix alba forms, Salix fragilis.
- Ordinary border soil: Salix purpurea 'Nana', 'Kilmarnock', most contorted forms.
- Dry, sandy or gravelly ground: Salix repens.
- Alpine or trough conditions with sharp drainage: Salix lanata, Salix boydii, Salix herbacea.
The root question matters more than the soil question. Willow roots travel widely and are drawn to water, which means drains, sewer pipes, soakaways and foundations are all potential targets. Plant well clear, and if you have a drainage problem, a boundary dispute or any concern about subsidence, take advice from a qualified arboriculturist or chartered surveyor before you dig.
Keeping a willow in bounds
Almost every willow tolerates hard pruning, and most look better for it. Two techniques do the work:
- Coppicing — cutting all stems back to 15–30 cm in late winter. Do this every one to three years for coloured stems, compact growth and a supply of cuttings.
- Pollarding — cutting back to a permanent trunk at 1.5–2 m. Useful where the tree must stay small but you still want height, for instance beside a path.
Prune in February or early March, just before growth starts. Cutting in autumn leaves wounds open through the wettest months and invites dieback. 'Kilmarnock' is the exception: trim its head after the catkins finish in spring, cutting back to the grafted stem.
Getting the choice right
Work backwards from the space. If you have a large, damp plot and want a statement tree, choose 'Chrysocoma' or Salix alba 'Tristis' and plant it far from buildings. If you have a small garden, take 'Kilmarnock' for a pot or a corner, or Salix purpurea 'Nana' for a low hedge you can cut every winter. For winter structure and cut stems, grow Salix × sepulcralis 'Erythroflexuosa' as a coppiced shrub.
Bare-root willows planted between November and March establish fastest. Soak the roots before planting, set the tree at the same depth it grew before, firm it in and water generously through the first two summers. Willow cuttings root so readily that you can push thumb-thick stems into damp ground in winter and expect most of them to take. That is the other advantage of coppicing: every prune gives you free plants for the boggy corner at the bottom of the garden.
Photo: Elena Elizarova / Pexels
