If your seedlings are to live through the shock of being transplanted outdoors, you need to gradually expose them to the sun, wind and spring temperatures. Just like people, plants can become sunburned, windburned or chilled if they aren't toughened before they're exposed. This process is called "hardening off."

Cole crops are hardier than many of the vegetables you transplant into the garden, but their yield will be much better if you give them time to harden completely.

1. Withhold water for a few days before moving the plants outdoors.
2. Move the plants outdoors for a few hours, placing them in a sheltered spot protected from wind and direct sun.
3. Gradually increase the length of time outdoors and amount of exposure until the plants are outdoors 8 to 12 hours at a time.
4. After five to six days of daytime hardening, leave the plants out overnight for two to three days. Bring them indoors if there's a danger of frost.
5. After 7 to 10 days of hardening off, your seedlings should be strong and ready for transplanting.