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Hardening Off Plants

What is cutin and why is it important when hardening off plants and preventing sunscald?

The outside layer of plant leaves is protected by a layer of epidermis, which functions similarly to human skin. In this epidermis, there is a layer of cutin, which is a waxy substance that protects the leaf from dehydration.

The cutin slowly increases as a plant receives more and more sunlight.

Young seedlings that haven’t been exposed to sun need to be exposed in small increments rather than just popping them out in a full day’s sun all at once.  This will allow the cutin protection to build up, and will protect your plants from dehydrating.

Cutin also protects tomatoes from getting sunscald.  I found this out the hard way last summer, when I pruned my tomato plants dramatically, and ruined half of my crop of tomatoes.

To harden off plants:

On a mild day, start with 2-3 hours of sun in a sheltered location.  Protect seedlings from strong sun, wind, hard rain and cool temperatures.

Increase exposure to sunlight and the elements a few additional hours at a time.  This way the cutin will build up and you will have healthy happy thriving plants.

A child’s wagon can be used to make the transport process easier.  Simply put plants in the wagon and wheel them to their acclimatization area for the hardening period, and wheel them back to the protected area when done.