Horticultural aide memoire Harden off
By now the glasshouse is full to overflowing with delicate green shoots. Soon they will adorn the garden, but first they must be hardened off or the low night temperatures will reduce them to purple mush. Transfer everything bodily to the cold frames and leave the lights securely in place. In the second week, prop the lights open a few inches, closing them if frost threatens, and covering with matting if need be. In the third week, give as much air as possible, keeping an eye on conditions. At the beginning of June everything can, as a rule, safely be planted out.