Give Them Tough Love: Hardening Off Your Herb Transplants

Spring is in the air, and most gardeners are feeling the need to get the gardening going! Whether you start your own seeds indoors at home, or buy your herb transplants from a garden center, it’s important that you give the plants some time to get used to their new world.

When plants are started indoors under lights or in a greenhouse, they live a protected life. They need to be introduced to the outside world gradually – a world occasionally wrought with strong winds, heavy rains, scorching sun, or chilly cold. If your transplants move from full protection to no protection too quickly, you’re likely to lose many of them. If you make that transition gradually – a process known as “hardening off” – your transplants are more likely to survive the change and continue to grow in their new home.

The general steps to hardening off your transplants:

1. Determine when you would like to plant the transplants into your garden.

2. About 7-10 days before you want to plant out, place your transplants in shady area outdoors, which is sheltered from the wind. On the first day, give your transplants only a quick taste – leave them out for only an hour or two, then bring them back inside.

3. Each subsequent day, lengthen the amount of time the plants are left outdoors by another hour or two.

4. After 2-3 days, move the plants into the sun for part of their time outdoors, then return them to the shade or partial shade.

5. Leave them in the sun for longer periods each day, but continue to bring the plants in at night.

6. After 6-7 days, your plants should be able to stay in the sun during the entire day, and can also begin to stay out during the night (if the night temperatures stay above about 50 degrees F).

7. After 7-10 days, the plants should be hardened off and ready to be planted into your garden.

8. Ideally, do your transplanting into the garden on an overcast day. After you transplant, be sure to water the plants well.

If you are taking young plants directly from inside your home under lights or directly from a greenhouse, it’s important that you give them the full 7-10 days to harden off. On the other hand, if you purchased your plants at a garden center or plant sale, they will have likely been hardened off at least to some degree. We try our best to at least get the hardening off process started with the plants we sell at our plant sale. In these cases, so you can probably speed up the hardening off process a bit – but be careful! Keep a close eye on the plants, and back up a few steps if you see signs of stress or wilting.

While it does take some time and effort, the hardening off process isn’t hard – and a little tough love will go a long way toward healthier, happier transplants in your garden!