So you decided to get a jump start on the growing season and now you’re ready to plant outside. Your tomatoes or peppers grew inside for a month away from the heat (or perhaps away from the cold), and you’re ready to get them started outside. You grab your shovel and a little plant and.. hold up! Did you just skip hardening off your plants??
“Hardening off plants, what’s that?” you might ask.
Hardening off your plants is basically a time of transition while your plants adjust to the temperature change so that it doesn’t come as quite a shock.
Hardening off your plants can take a week or two, depending on the weather you’re experiencing. The first few days I recommend keeping your plants in the shade – either on your porch or under some other covering. This will help them adjust to the sun. If it’s raining out, I also suggest keeping your plants under something so they don’t get saturated. A light rain is fine, but a downpour might snap your little seedling’s branches.
I also recommend securing your plants so that they don’t fall over in the wind. Peat pots are very lightweight. Set a couple bricks or other heavy outdoor objects around your pots so that they don’t fall over.
If it’s raining or overcast when you harden your plants, keep in mind that your plants haven’t adjusted yet to sunny weather. This is when you might want to prolong your hardening off period to two weeks. You’ll want your plants to get some sun exposure before you transplant.
Here’s a recommended transition time for you to keep your plants outside. This is for daylight hours, with the final day a full 24 hours where your plants are also left out at night.
Hardening off your plants schedule
- 1st Day: 2 hours (with shade)
- 2nd Day: 4 hours (with shade)
- 3rd Day: 6 hours (with shade)
- 4th Day: 8 hours (without shade)
- 5th Day: 10 hours (without shade)
- 6th Day: 12 hours (without shade)
- 7th Day: All day – 24 hours (without shade)
- 8th Day: Transplant
If you work during the day and you don’t have anyone to bring in your plants for you while you’re gone. If you have a typical 8-5 job, I recommend starting on a Friday evening when you get home.
Hardening off your plants schedule (for busy schedules)
- Friday Day 1: 3 hours after work (with shade)
- Saturday Day 2: 5 hours (with shade)
- Sunday Day 3: 7 hours (with shade)
- Monday Day 4: 9 hours (with shade – you won’t be home to check on your plants, so I recommend keeping your plants in the shade a bit longer)
- Tuesday Day 5: 11 hours (with shade)
- Wednesday Day 6: 12 hours (without shade)
- Thursday Day 7: 12 hours (without shade)
- Friday Day 8: All day – 24 hours (without shade)
- Saturday Day 9: Transplant
Make the transition time as gradual as possible, but make it around YOUR schedule. Your garden should be all about YOUR lifestyle.
When you’re hardening off your plants you’ll want to water them when you set them out at the beginning. And then If you’re able to I recommend checking on them after an hour to see if they need more water. You’ll know this if the soil is dry, but not if the leaves are wilted.
A word of advice – when I first hardened off my plants I started to panic. Even though I only left them out for 2 hours on a warm sunny day under the protection of shade and kept watering them.. they started to wilt.
This will happen because of the temperature change. And it’s OK as long as you’re slowly increasing your plants’ exposure. When you bring your plants back inside, make sure the soil is damp. After a few hours, your plants will perk up again.
Even after I transplant I notice my plants wilting the first couple weeks in the ground before the roots really start to take off. One thing that does help with this is using a garden cover. It keeps your plants cooler during warm seasons. Feel free to read more about it here: Beat the Heat: Using Shade Cloths in the Garden
If you don’t start your seeds indoors and are interested in learning more, check out How to Start Seeds Indoors.
Happy Gardening! 🙂