Hardening off

Credit: Carolyn Herriot

Unsettled weather in spring makes it important to harden seedlings off when they are moved out of a protected environment.

Allowing time for a gradual adjustment to change in temperature prevents seedlings from going into shock. Harden young plants off, for a period of a week to 10 days, by moving them outside in the daytime and back inside (or cover) at night.

Trays of cool-weather seedlings can been moved outside in early spring, in preparation for transplanting into the garden. They start outdoors life below an overhang, so that they are still protected from frost at night. Their next move is onto open tables, after which they can safely be transplanted into the garden.

Cool-weather seedlings include: peas, lettuce, chard, spinach, chicory, raddichio, arugula, nasturtiums, brassicas (cabbage, cauliflower, kale, broccoli, Brussels sprouts). The onions and leek seedlings are still too small to harden off.

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