How to Grow Lawson Cypress
Chamaecyparis lawsoniana
Lawson cypress is a versatile, dense evergreen conifer ideal as a specimen tree, hedge, or screen. Plant in well-drained soil in full sun to partial shade, sheltered from cold drying winds. Water regularly for the first two seasons then reduce; established trees are reasonably drought-tolerant. Mulch annually. Clip hedges in late spring and again in late summer — always into green growth only, never into old bare wood. Hardy to about -15°C once established.
Yearly Lifecycle
Care Essentials
Feed young trees with a balanced slow-release fertiliser in spring for the first two to three years. Established Lawson cypress rarely needs supplemental feeding; an annual mulch of composted bark over the root zone is usually sufficient.
Watch For
- Phytophthora root rot — avoid waterlogged soil; most common cause of decline
- Cypress aphid (Cinara cupressivora) causing brown patches on foliage
- Keithia blight (Didymascella thujina) on hedges and young trees
- Wind scorch on exposed sites, especially during dry cold spells
Companions
Rhododendrons, Ferns, Hostas, Heathers
Care Requirements
Light
Full sun to partial shade
Tolerates a wider range of light conditions than most conifers. Full sun produces the densest, most compact growth. Partial shade is acceptable but may result in slightly looser foliage. Avoid deep shade.
Watering
Moderate; regular for first two seasons
Water deeply once or twice a week during the first two growing seasons. Established trees are moderately drought-tolerant but do best with consistent moisture. Waterlogging must be avoided at all times as it encourages Phytophthora root rot.
Fertilizing
Light spring feed for young trees only
Apply a balanced slow-release granular fertiliser in early spring for the first two to three years. Established trees need no feeding beyond an annual mulch of composted bark over the root zone.
Pruning
Light clip only; never into bare wood
Trim into green growth in late spring and late summer only. Never cut back into old bare wood as the tree will not regenerate from leafless stems. Remove dead or diseased wood at any time.
Spacing
5-6 m as specimen; 45-60 cm for hedging
Specimen trees need at least 5-6 m from buildings, boundaries, and underground services. For hedging, plant 45-60 cm apart. Always check the mature size of your specific cultivar, as sizes range enormously.
Growing Tips
Good drainage is non-negotiable
Lawson cypress is highly susceptible to Phytophthora root rot in waterlogged soil. Always plant in free-draining ground and avoid low-lying spots where water pools after rain.
Never cut into bare wood
Unlike many conifers, Lawson cypress will not regenerate from old leafless stems. Always clip with green foliage on the side you are cutting into, or the brown patch will be permanent.
Timing hedge cuts
Trim once in late spring when new growth has hardened, and again in late summer. Avoid cutting in very hot or very cold weather as fresh cuts scorch easily.
Water in the first two years
Once established, Lawson cypress tolerates moderate drought. The critical window is the first two summers — keep the root zone consistently moist to allow the roots to extend into the surrounding soil.
Annual mulch pays dividends
A 5-8 cm layer of composted bark or wood chip over the root zone in spring retains moisture, suppresses weeds, and feeds the soil fungi that conifers rely on. Keep mulch off the trunk to prevent rot.
