Harvesting and Aftercare of Seakale
The blanched shoots are ready for harvesting when they are 18-23 cm (7-9”) long. Scrape theaway from around the crown and then cut the shoots cleanly with a sharp knife, so that about 1-3 cm (¼-1”) of woody crown is cut off, together with the new young growth.
If you like, you need not cut off all the shoots on one plant at the same time. Instead you can remove the large, older, outer shoots first and then remove the younger shoots when they have grown a little bigger.
Forced roots are useless once they have produced a crop of blanched shoots and should be thrown away. Outdoor roots, however, can be left to give you another crop the next year. With care and attention they are quite able to produce a crop for six or seven successive years. After harvesting, open them up to the light, and remove any protecting covering such as leafmould. Then fork around the plants and add a dressing of rotted manure or garden.
When the weather becomes warm in the spring, remove any small shoots remaining and rub out all but the three strongest buds. The plants can then be left to grow on naturally.
As the plants become older the central part of the crown of each gradually loses its vigour, though new shoots continue to be produced at the edge. In this way a bed should continue to produce a good crop indefinitely. If you wish to abandon an old bed, however, be careful to remove all roots and pieces of root from the ground. Any bits left in the ground will grow up like.