The Process of Acclimating Seedlings to Outdoor Conditions is Called Hardening Off
You can extend your growing season by starting seeds indoors. Once seedlings have grown into young plants, take them outside garadually to provide them sun and wind exposure before you plant them in the garden or patio container.
Seedlings Begun Indoors
Transplants that have been raised indoors are soft, and must get used to sun, wind and rain. It is best to let them “harden off” gradually for several days before planting in the garden.
Move the trays of transplants outdoors to a sheltered, shady place out of the wind. Keep them well-watered. (If they wilt anyway, bring them back inside until they perk up again.) Bring back indoors each evening.
After two days, leaves and stems should be stronger. Move transplants to a half-sun location for 2 more days. When they are tough enough to go through the day without wilting, it’s time to plant them in the garden or container.
Plants Received in the Mail
Young plants ordered through the mail do not need hardening off in the classic sense, but they definitely appreciate time to rehydrate, rest, and acclimatize to your growing zone before being popped in the ground.
When your mail-order plants arrive, remove them from the shipping box immediately. As you unpack them, carefully remove all packing materials, including any mulch-like matter around the base of potted plants.
If you are receiving bareroots, fill a bucket with water and unwrap the bareroots gently, placing them into the water up to the top of the roots. Let them soak in the water for several hours or even a whole day before removing them and planting them in your garden. This treatment just wakes up the roots!
If you are receiving potted plants, place the pots in a shaded, secure location, away from drying winds and curious pets. Water them thoroughly, so that the water runs out the bottom of the pot. Unless you are expecting harsh weather, leave them in this protected area overnight.
Next morning, look at the plants. If they seem refreshed and ready to go, you can probably plant them today, although another day of recovery might be advisable. Re-water them, not quite so thoroughly (unless they look dry), and then either let them rest for another day and night or plant them.
When it’s time to plant, try to do so either early in the morning or toward evening. A cloudy day is ideal, but Nature doesn’t always cooperate, and most plants adapt just fine. If rough weather or strong winds are expected, pop a Kozy Coat around the new plant or set up other protection. And remember to water the plant thoroughly at planting time and again a few days later, as it finds its feet in its new home.