Soil must be well prepared in a sunny, open site. Sow seeds into peat pots/modules from March to July and transplanted when plants are 10-15cm tall, at 30cm square spacing. Alternatively seeds can be sown directly into very finely prepared soil, in rows about 13mm deep allowing 30cm between rows. Cover the seeds lightly with soil. Thin to 30cm apart in the row. Can also be sown more thickly as ‘salad leaves’ from March to August.
Water after sowing directly or transplanting and keep plants moist at all times.
Harvesting of mature hearts can commence after about 80 days from sowing. To reduce the bitter flavour the plants should be blanched in succession. Once blanched the hearts will deteriorate in quality, so blanching should be carried out to fit in with harvesting requirements. Blanching is achieved by tying up the lower leaves to cover the plants or by placing a 25cm size pot over the plants and blocking the drainage hole to exclude light.
March, April, May, June, July, August