Growing Hints 2: Widdringtonia cedarbergensis

• The Clanwilliam cedar is propagated from seed sown in autumn, in well-drained, sandy soil.
• Use either coarse river sand or a 1:1 mixture of well-rotted compost or washed peat and river sand. Keep the medium moist, but not too wet. Sow in plugs which will help with drainage.
• Germination takes 3-4 weeks and seedlings can be transplanted as soon as they are large enough to handle. The seed germinates relatively well, and will benefit from treatment with Instant Smoke Plus Seed Primer.
• Initial growth is good, and saplings are best grown on in semi-shade.
• The Clanwilliam cedar is susceptible to the root fungus Phytophthora cinnamomi, so sterile soil should be used, and root disturbance kept to a minimum. Fungal infection is quite a problem so we recommend dusting the seed with a pre-emergence damping off fungicide like Apron XL which is available from Syngenta in the South Africa. (https://www.syngenta-us.com/seed-treatment/apron-xl) 
• Do not allow the saplings to dry out. Adult trees may be drought-tolerant but young trees in containers will not survive a total drought.

The above is the sowing recommendations for the Mediterranean areas of the South Western Cape. In other areas the seed can be sown at the beginning of the growing season.

SANBI Red List: http://redlist.sanbi.org/species.php?species=208-1.