Starting your flowers and vegetables from seeds is easy and fun. It allows you to grow lots of varieties you can’t always find as starter plants, and because seeds are relatively inexpensive, it’s an economical way to garden. Use a seed starting kit, or fill clean, empty containers with seed starting mix. Keep your seeds near a bright window, and watch for them to germinate.
But it’s not always easy for seedlings to make the transition from the growing conditions in your home to the harsh world outside. That’s why it’s important to harden the sprouts off before moving them into your garden. Hardening off is the process of gradually exposing them to sun, wind, and rain. This “toughening up” helps prevent transplant shock, which can cause seedlings to become stunted or die. Hardening off might seem like an extra step, but it’s not. It could mean the difference between success and–well, having to start over.
How to harden off seedlings:
- First, look at your seed packets to see when it’s safe to plant outside in your region. Start hardening off the seedlings 7 to 10 days before that date.
- On the first day, put your seedlings outside in a sheltered spot, like on a covered porch or under a tree. Leave them there for 3 or 4 hours before bringing them back in. Do this every day, adding 2 or 3 hours a day to their time outdoors. Bring them in every night.
- After 2 or 3 days, put the seedlings in a spot that gets morning sun. As the sun gets hotter in the afternoon, move them into some shade. Again, bring them in at night.
- After 7 days, the seedlings should be able to stay outside in the sun all day. Check them often and don’t let them dry out. Leave them out all night as long as the temperatures don’t dip below 50 degrees Fahrenheit.
- The seedlings are ready to transplant after 7 to 10 days. Try to plant on a cloudy day, and water thoroughly and regularly, if there’s no rain.
Using a Cold Frame to Harden Seedlings:
If you have a cold frame, use it to harden off your seedlings. Again, start 7 to 10 days before you want to transplant the seedlings into your garden. Put them in the cold frame and open the cover for 3 to 4 hours on the first day. Leave it open an additional 2 or 3 hours each day. If the temperatures drop into the 40s, close the cover at night and plug in your heating cables, if you have them. Transplant on a cloudy day, if possible. Keep your seedlings well watered, and watch them grow.
Check out these Garden Club stories about Seed Starting:
- Start Seeds in Peat Pots for a Jump on Spring
- Mind These Do’s and Don’ts When Starting Seeds
- Starting Vegetables from Seeds