Chamaecyparis lawsoniana Seeds | Lawson’s Cypress
LATIN NAME: Chamaecyparis lawsoniana
COMMON NAME: Lawson’s Cypress, Port Orford Cedar
Plant Profile
Lawson cypress is a tall evergreen conifer from a very small native range: a narrow strip of coastal forest in southern Oregon and northern California, where it grows in moist valleys with high rainfall. In the wild it reaches sixty metres, with a straight trunk and a narrow crown; in gardens it is more often seen as a hedge or a specimen five to fifteen metres tall.
The foliage is flattened, fern-like and strongly resinous when crushed, and the small round cones sit on the underside of the sprays. Hundreds of named cultivars offer gold, blue, silver and green foliage, which is why the species is so widely planted despite its size.
Science & Biotechnology
The species is important in forestry and in plant pathology. Its timber is strong, straight-grained and resistant to decay, and it was heavily logged in the twentieth century, which led to the establishment of reserves and seed stands.
A root disease caused by Phytophthora lateralis has killed trees across the native range and in planted forests in Europe, and research has focused on identifying resistant families and on hygiene to slow the spread. The species is also a parent of many garden cultivars, selected for foliage colour and habit, and some of those are more widely grown than the wild tree.
Uses & Benefits
In the garden it is used for hedges, screens and specimen planting, and the coloured cultivars are among the most useful evergreens for structure. The timber is prized for boat building, fencing, joinery and arrow shafts, and the wood’s resistance to rot makes it valuable for outdoor use.
In Japan the related hinoki is used for bath tubs and shrines, and the oil is distilled for its calming scent. Lawson cypress is one of the most widely planted conifers in temperate gardens, and old hedges of it are a familiar sight in British and New Zealand suburbs.
The wood is also used for crates and for the frames of greenhouses, where its lightness matters.
Growing from Seed
Sow in spring after four weeks of cold stratification, barely covering the seed, at 15-18C. Germination is usually good. Seedlings are slow at first and should be potted on into deep containers, since the roots resent disturbance.
Plant out in autumn or spring in moist but well-drained soil, in sun or light shade. Avoid sites that flood, and do not move established plants; the species also needs shelter from drying wind in exposed positions. Clip hedges in late summer, when the cuts heal quickly. A windbreak of other trees on the exposed side prevents the browning that follows salt spray. Young trees should be watered in their first two summers.
Our Take
Lawson cypress is the best hedge conifer for many sites, and one of the worst trees to plant where it will outgrow its space. Choose a cultivar, not the species, for a small garden.
Related Reading
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