Living garden structures - such as arbours and tunnels - using willow are easy and fun to create.
Willow stem harvesting begins in autumn and may continue through to early spring; projects are carried out during these months. Some specialist growers supply instructions along with suitable plant material. Store live stems with the bases immersed in water until needed.
Choose a part of the garden that is naturally moist and sunny, avoiding areas with open drains. Ideally clear grass away from the base of the structure before planting. The staves (willow stems) can be pushed 30cm (12in) or more into the ground making a hole first for thicker stems. Arbours, tunnels, wigwams and living fences can be created, incorporating simple or complicated weaving designs.
Any point where stems cross may pressure graft together. Encourage this by tying joins together with tarred string or thin pieces of willow.
Shoots will sprout from the staves inserted into the ground. If cut back the stems should thicken; useful if thinner one-year-old shoots have been used to construct your feature. Trimming can be carried out in the summer or left until winter.
New growth can also be woven in to fill gaps in the design or strengthen the structure. Use a basic weave to take the new shoots under and over the framework branches, but diagonally above the horizontal. Weaving is best left to the winter, as the shoots are very brittle in the summer and liable to snap.
To keep down weeds apply a deep mulch of bark chippings or composted bark around the staves, or plant through a weed control membrane. Water the site thoroughly in dry spells.
Although willow will grow in most soils, a moisture-retentive soil and sunny site will encourage more vigorous growth. If structures are intended to hold soil, line the weaving on the inside with plastic or fabric before filling with soil to make the woven stems last longer.
Alternatives to willow for living bowers and arches include lime (Tilia spp), whitebeam (Sorbus aria) and laburnum. These are best planted as young trees and initially trained over a framework. New shoots are tied in as they grow and, if a clear stem is required, lower laterals are progressively removed. Once the plants are established, any training supports can be removed. The leading shoot can be headed back and outward growing shoots trimmed on an annual basis.