While it is spring here, it certainly hasn’t felt like spring in the last few weeks. The temperatures have been very wintery, yet the seedlings under the lights in my basement continue to grow. I started them weeks ago, long before I knew it was going to be a very cold spring. If you have a cool spring or even simply the cooler weather of a normal Northern spring, what can you do to give your vegetable seedlings an easier transition to the outdoors?
Why Harden Off Vegetable Seedlings Before You Transplant Them?
Hardening off is the term used when you transition seedlings from a warm, light, and sheltered indoor environment to the big, wide world of the garden. The environment is different in the garden, and vegetable seedlings can have a hard time adjusting. There is more wind in the garden, and there is rain instead of a mister. There are also wide temperature variations, much wider than vegetable seedlings would find indoors. For all of these reasons, it is important to give vegetable seedlings some time to get used to the great outdoors.
How to Harden Off Vegetable Seedlings
A few weeks before you want to plant your seedlings in the garden, begin to transition them outdoors. Make the transition to the outdoors a gradual one, if possible. If you have a sheltered area like a deck or even an unheated garage, this is the perfect place for the vegetable seedlings to get adjusted. Bring them to this sheltered location for a few hours a day, preferably at a time in the early evening when it is not too hot and not too cold.
Adapt The Hardening Off Process Based on the Seedlings
Gauge the plants’ reaction to the new temperature and moisture levels. If they seem to have problems, leave them indoors for a few more days. Gradually shift to longer and longer times outdoors, and place the seedlings in an area that is more exposed to the elements such as wind and rain. In a few weeks, the seedlings that have survived will be vigorous and used to the new place where they will live.
When the vegetables are ready, remove the seedlings from their containers and place them in moist ground. Take care to support the seedlings with support structures if required. Look in on the newly-planted seedlings to ensure that they survive. If they do not, learn from the experience and change your hardening off process next time.