Hardening Off Seedlings

If you’ve grown some vegetables from seed, you will need to slowly introduce them to the weather outside a couple of weeks before time to plant so they can get used to the wind, rain, and weather outside.

You may have raised your seedlings indoors under lights, in a sunny window, or in a greenhouse, and they need time to get used to heat, wind, and weather before planting in their permanent location.


Timing is important when growing vegetables from seeds.  Plant them out too early and they may have root systems too underdeveloped to survive.  Plant them too late and their roots may have become too clogged in the pot.  This is why it’s important to keep a record of when you planted each variety and when they were ready to plant out.  This way, you can plant your seeds at the optimum time to have a plant ready to go into the garden when the weather is the most favorable.  It may take a few tries to get this right.

Introducing the Outdoors

When seedlings are about two weeks away from being ready to plant out in your garden, pick a mild day with a light breeze and move your seedlings into a shady spot outdoors.  Only leave out a couple of hours the first day, gradually increasing the time over two weeks until they can stay out all day, then overnight when threat of frost is gone.  If you have a cold frame or greenhouse that you can open to the elements, these are great places to put your seedlings for gradual exposure.

Garden Center Plants

 Garden center plants have usually been outdoors for a while and shouldn’t need to be hardened off.  They may also have been in the pots a long time and may have roots curling around the root ball.  When getting ready to plant them, be sure to pull some of the roots away from the ball so they can begin spreading their roots outward. Plant with the top of the soil in the pot level with the garden soil.