How to Harden Off Plants

Learn about the importance of “hardening off” your plants, what it is and how to do it.

When you start seedlings indoors, they need a gradual adjustment period before you can kick them out of the house or greenhouse and plant them outdoors.

The environment in your home in comparison to the environment outdoors is greatly different.

Inside is climate controlled. Outside, there’s wind, sun and temperature fluctuations.

So to keep your plants from being shocked, stunted or possibly even dying, hardening off is a way to make it an easier transition.

How to Harden Off the Plants

There are a few ways you can do it.

The “Toughen them up” Method

One way is to withhold water until they begin to wilt, then watering again. It’s sort of a “toughening them up” method. It is a fine balance though, between wilted and dead.

The Cold Frame Method

Another is to transition them out into a cold frame. Great if you have cold frames set up.

The Gradual Transition Method

My preferred method is a gradual move.

About 10-14 days before you plan to plant them in the garden, begin setting the plants outside in a sheltered area for a few hours at a time, about 3-4 hours to begin with. I find that my covered back porch works great for this.

Avoid direct sunlight. Don’t put the baby plants in direct sunlight right away, or their little leaves may get scorched. (I’ve learned this lesson the hard way.)

You also want to make sure that their soil doesn’t dry out. They will need a little more water than they did in the house, simply because the quantity of soil they have is so small, and they are now being exposed to more elements.

I also place the plants up on a table so that the dogs and other critters (insects, slugs) don’t have easy access to the plants.

Each day leave the plants outside for a little longer, until eventually you are leaving them out all day and night. Then your plants are ready to go!

Learn about when to plant in your area.

Happy gardening!