In a few weeks it will be time to start getting those seedlings you started indoors a couple months ago used to living outside. This process is called “hardening off.” The conditions inside your house are much milder and have much less fluctuation than conditions outside. If you suddenly put your plants (who have lived their whole lives in your window) outside, they will die very quickly from the intense sunlight, cold nights, wind and dry air.

So, to harden off your sweet little seedlings, here is what you do:

  1. It is important to be gradual with your hardening off. Begin the process at least one week before you plan to plant the seedlings in the garden.
  2. On a day when the weather outside isn’t extreme (not really windy, cold, or super hot), put your seedlings outside in a sheltered area for a few hours and then bring them back in.
  3. Over the next few days, increase the time they spend outside by a couple hours or so each day, still protecting them from extreme weather.
  4. After about a week or so, your plants can probably be outside all day if it isn’t super windy or if there isn’t a sudden cold snap, etc.
  5. Once the night time temperature is consistently in the 50’s or above (some plants can be ok in the 40’s such as lettuce, onions and brassicas), you can leave your seedlings out overnight (but watch the forecast! You don’t want a sudden frost to kill all your hard work!)

If you tried a seedling exchange this year, you are probably almost ready to bring your seedlings back together and exchange plants. It would be a good idea to give everyone who participated information about how to harden off their seedlings, especially if you have any novice gardeners in the group. It can be discouraging for a beginner to grow their seedlings, only to have them all die from exposure because they didn’t know about hardening off.


If you are saying to yourself, “Yes, nice idea, but I work 5 days a week and can’t be home to schlep plants in and out of the house!” There are ways to work this out. You could begin on a Friday evening, putting your plants out for the last few hours of sunshine. Then Saturday, put them out for 3 hours or so in the morning. Sunday, put them out for about 5 hours. Then Monday when you go back to work, put them outside, up against the East side of the house, so they will get 6 hours or so of light, but after noon, when the sun has moved to the West side of the house, they are no longer getting direct light. Then Tuesday, put them on the East side of the house again, but a few feet away from the wall, so they will get direct sunlight a little more than the day before. Then continue this, each day moving the plants farther from the East wall than the day before so the plants are getting more hours of direct light each day. Once again, pay attention to the weather and don’t put them out at all if it will be windy, rainy, or cold.

Now is also the time to be thinking about how you can make your garden more beneficent! What can you do with the things you plant and the way you plant them that will bring extra benefit to not only yourself and your family, but your community and the planet?