The Gardener's Almanac

Hardening off

Gradually increase the ventilation around the seedlings by moving them into either a cold frame or a cool room.

During daylight hours (if conditions allow) lift the lids of the cold frame, or if they are being kept in a cool room move them outdoors remembering to take them in each evening.

Plants at varying stages;

Finally leave them out in the open (if conditions allow) for approximately a week prior to planting out into the beds.