Hardening off your transplants

An important part of growing your own seedlings is hardening off your transplants. Don’t skip this step or you risk loosing your transplants completely!

Hardening off your transplants

This post contains affiliate links, clicking on them with not cost you any thing extra, but does allow Stoney Acres to make a small commission on your purchase through the Amazon Affiliate Program!

You have dutifully cared for your new seedlings indoors for 6 weeks and you have a tray full of beautiful plants that look ready to head out to the garden. What now?

There is one more step on the seed starting process that you shouldn’t skip.

Seed Starting Banner $20 300x250

Hardening off your transplants

Hardening off your transplants is the important final step before planting your seedlings in the garden. For the last 6 to 8 weeks your seedlings have been growing in near perfect growing conditions. If you have done your job right your seedlings have been receiving plenty of water, light and nutrition. They have also been growing indoors with very moderate temperatures and no wind. All of this leads to very healthy starts but they are also a little pampered and tender.

The process of hardening off your transplants, slowly prepares your new plants for the harsher conditions out in the garden. Skip this step and you risk causing a shock to your plants from which they may never really recover. Hardening off your seedlings is accomplished by slowly exposing your seedlings to the conditions out in the garden.

When to start hardening off your transplants

Start hardening off your transplants at least a week to ten days before you intend to plant them in the garden. For the first 2 or 3 days bring your seedlings out side for only a few hours, at the most 4 hours. If you are hardening off your seedlings in the cool spring then these first few days could be directly in the garden. If you are hardening off your seedlings in the hot summer or fall you may want to make those first few days under a shady tree so the plants can first get use to the heat with protection.

As the days go on continue hardening off your seedlings by increasing The amount of time they spend outside each day by a couple of hours per day. If you are hardening off your seedlings in the early spring be sure that some of the time spent outside also includes time at night so your plants can adjust to the cold night time temperatures as well.

How long should you harden your transplants

I usually shoot for at least a week to ten days of hardening off time. Be sure to include hardening time in you overall calculations of time for your seedlings. You want most seedlings to only spend about 6 to 8 weeks in pots, any more time than that risks your seedlings becoming root bound in the pots. That 6 to 8 weeks must include the hardening off time so start setting your plants out at the 5 to 7 week mark.

Seed Starting Banner $20 300x250

While you are hardening off your seedlings you need to continue watering and fertilizing as you normally would. In fact be extra sensitive to the water needs of your seedlings while they are hardening. Those small pots don’t hold a lot of moisture and can dry out quickly on a hot or windy day. So be sure you check the condition of your plants often while they are outside. Once your seedlings have been hardened off get them out of those restrictive pots and into the garden!

Remember hardening off your transplants is a process you don’t want to skip. Doing it creates stronger and healthier plants for your garden. In fact I recommend hardening off store bought seedlings for at least a week as well!


Subscribe Button

Facebook Like Button

Hardening off your transplantsFB



  1. Nancy Davis May 16, 2017 8:34 pm Reply

    Hardening off seedlings if hard for me. Makes me nervous! LOL I am wondering though about how you harden off plants bought from the nursery. How do I treat them? I don’t harden them off but try to protect them from too much cold, wind or sun. Nancy

    • Mr. Stoney May 17, 2017 9:03 am Reply

      You harden store bought the same way you would your own. Give them at least a week of increasing exposure to your garden conditions. Those store bought starts have been living under the same conditions any you have been growing on your own. They are pampered and need to be hardened. It would make me nervous to put starts out in my garden without hardening them first 🙂

Leave a Reply