Monday, August 1, 2016

Transpiration-Vegetables Wilting in the Sun by Joyce D'Agostino

Photo by Carol King

Have you ever hurried home after work, looking forward to some quality gardening time only to find some of your pumpkins and squash look like they have died?
If the wilt is not caused by insects, then chances are what you are observing is called Transpiration. This process is normal and your plants will likely bounce back later to their former healthy appearance once the temperatures cool down. 
Transpiration is the loss of water vapor through the stomata of the leaves. The stomata is the outer layer of the leaf’s outer “skin” layer. 
Plants that often show dramatic transpiration are ones like pumpkins, squash and gourds which may develop very large leaves. Transpiration actually is a very effective process for the plant to move minerals up from the root, to help cool the plant and for the “turgor pressure” which helps non-woody plants have their form and shape. 
Help your plants handle their transpiration efficiently by keeping them well hydrated, watering in the cool time of the morning. Once your hot day cools down, you can recheck your plant and the soil area. Chances are that your plant has sprung back up to its normal shape and will continue on with healthy growth and production. If your area seems especially hot and dry, using some light shade cloth may help protect your plant from sunburn as well.
For more information on transpiration and other related processes, refer to this GardenNotes publication: