Up until now, our seedlings have had a pretty easy life. They’ve been thriving in a temperature-controlled environment, sheltered from extreme temperatures, rain, and wind. We want to put them outside in a few weeks, after it looks like the chance of frost has passed. If we just moved them outside from their little comfort zone, without any preparation, they would likely do very poorly.
Seedlings have to be hardened off before they can be planted in their beds. This process gradually exposes them to the elements.
You can do a little preparation inside to strengthen your seedlings. On warm and slightly windy days, open some windows to let a cross-breeze flow across the path of your seedlings for an hour or so. This will expose them to the wind; their stalks will become stronger. Alternately, you can use a fan; place it some distance away and keep it on low.
Start 7-10 days before transplant.
- Start on a mild day. That is, don’t pick a day that’s too hot or one that’s rainy. If it’s cold, wait.
- For ease of transport, consider putting your seedlings on a tray that you can easily carry in and out of the house.
- For 2-3 days in a row (provided the weather is not inclement), move your plants outside for a few hours. Place them in a sheltered, shady spot, such as against a building or under a tree. Do not place them high up on a table or deck where they’ll get the full brunt of the wind and sun. Each day, increase the amount of time they’re out by an hour or so, so that the first day, they are outside for 1-2 hours, then the next day they are out for 2-3 hours, and so on. Gradually reduce the amount of water they receive, but don’t let them wilt.
- For the next 7 days, place them out in the morning sun for a few hours, then move them back into the shade for the bulk of the day. Gradually increase the amount of time they spend in the sun, so that, again, they spend 1-2 hours in the sun one day, then 2-3 the next, and so on. Ensure that they don’t get too hot; if they begin to wilt, move them into the shade, and water them.
- After a week, your plants should be able to tolerate the wind and sun for the day. So long as the forecast still looks favourable, you can plant them.
- Plant them on an overcast day so that they don’t get too hot, and water them well. Apply an organic fertilizer to give them a boost and to minimize transplant shock. Keep them watered as they adjust to their new life outdoors.
Uh-oh, the forecast changed!
In the event that the forecast changes, and strong winds, heavy rain, or cold temperatures are forecast, your plants may still be okay. Temporaily cover them with row covers, plastic containers, plastic sheets, or anything that will shield them from the elements without damaging them or eliminating their exposure to the sun. If you’re using some sort of sheet, just make sure to place something under it to prop it up so that it doesn’t flatten your plants.