What specific requirements are needed to germinate Gaultheria procumbens in soilless media?
Any tips on seed stratification, cultural advice, etc., etc.?
The information below comes from the website of Plants for a Future:
“The seed requires a period of cold stratification. Pre-chill for 4-10 weeks and then surface sow in a lime-free compost in a shady part of the greenhouse and keep the compost moist. The seed usually germinates well, usually within 1- 2 months at 20 c, but the seedlings are liable to damp off. It is important to water them with care and to ensure that they get plenty of ventilation. Watering them with a garlic infusion can also help to prevent damping off. Prick out the seedlings into individual pots when they are about 25mm tall, and grow them in light shade in the greenhouse for at least their first winter. Plant them out in late spring or early summer. The seedlings are susceptible to spring frosts so might need some protection for their first few years outdoors. The leaves remain very small for the first few years. If you want to grow from cuttings, use half-ripe wood 3-6cm long, and in July/August place in a frame in a shady position. They form roots in late summer or spring. A good percentage usually take. Division can be carried out at almost any time of the year, but works best in the spring just before new growth begins. Very easy, larger clumps can be replanted directly into their permanent positions, though it is best to pot up smaller clumps and grow them in a cold frame until they are rooting well. Plant them out in the spring.”
I consulted the book, Seeds of Woody Plants in North America by James A. Young (Dioscorides Press, 1992, rev.ed.), and the general information on Gaultheria states that cold dry storage will help maintain seed viability. G. procumbens has 6800 seeds per gram. Seeds are initially dormant and prechilling is needed for germination (from 30-120 days with a variety of substrata). Salal (G. shallon) seeds appear to require light for germination. This resource says that G. procumbens seeds should be sown in the fall.