leylandii

Leylandii, or Leyland cypress, is a fast-growing evergreen conifer used for hedges and screens. It is a hybrid between Monterey cypress (Cupressus macrocarpa) and Nootka cypress (Chamaecyparis nootkatensis). In cultivation it is often listed as Cupressocyparis leylandii.

It forms dense, dark-green foliage on upright, columnar branches and has a very rapid growth rate in favorable conditions. Left unpruned, a hedge can reach several meters in height within a few years, and an unpruned tree can eventually grow tens of meters tall.

Cultivation: It prefers full sun and well-drained soil and tolerates a range of soils and climates. Once established it is relatively drought-tolerant but vulnerable to waterlogging. It benefits from regular pruning to maintain shape and size, with light yearly trimming or periodic trim to keep the hedge dense. Heavy pruning should be avoided in a single season.

Problems: Leylandii can be affected by canker diseases such as Seiridium cardinale, which causes dieback, and by other pathogens, pests, and root rot in wet soils. The rapid growth and tall form can make hedges susceptible to wind damage if not properly maintained.

Uses and considerations: Widely planted for privacy screens, windbreaks, and formal hedges. Very tall hedges can shade smaller plants and may raise visibility or wind-loading concerns, leading some local rules or planning guidelines to limit height.