transplanting seedlings outdoors

How to Harden Off Plants

Preparing Seedlings for Being Planted Outdoors

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Young, pampered seedlings that were grown either indoors or in a greenhouse will need an adjustment period to acclimate to outdoor conditions prior to being planted in the garden. This transition period is called “hardening off.”  

Hardening off seedlings gradually exposes the tender plants to the wind, sun, and rain. toughening them up by thickening the cuticle on the leaves so they lose less water when exposed to the elements. This helps prevent transplant shock, the term used for seedlings that languish, become stunted, or die from sudden changes in temperature.

The length of time a seedling requires to harden off depends on the type of plants being grown and the temperature. Be flexible when hardening off your seedlings and prepare to whisk them indoors or cover them if there is a late freeze or snow.

There are three approaches to hardening off plants:

Learn here about the three approaches to hardening off, methods for making your seedlings adjust and acclimate to outdoor conditions.