Many thanks!
I grow this plant in a clay pot which is plunged in a sand bed within a sunny well-ventilated alpine house. The compost is a very mineral mix of 50% pumice: 20% gritty silica sand: 20% perlite: 10% sphagnum peat. Even in Scotland some shade is required on hot sunny days. Last year the plant set a small amount of seed which was sown in October; the seeds germinated about 6 weeks ago. Any advice on managing the seedlings would be most welcome.