Sunday, July 8, 2012
I must admit to great relief to have the power back on after the storm a week ago Friday (5 days no AC), so I can get out of the sweltering heat. Unfortunately, my plants are not so lucky. We are expecting one more day of very high heat (over 100 degrees) in this heat wave, then a cool down that will give my plants some time to recover. One thing you might have noticed are brown, squishy patches on some of your fruit, and this is called sun scald. I mostly get this on peppers and tomatoes (yes, both are botanical fruits that we treat as culinary vegetables) and have have also gotten some on eggplant. Above are two photos of peppers suffering from sun scald: the top is a smaller patch of damage and the bottom photo shows a larger patch. Sun scald can happen at lower temps, but the hotter it is, the more likely it will occur. It occurs when plants have insufficient leaves to provide shade for the more delicate fruits. Promoting stocky growth through early pruning helps produce more leaves to shade the fruits. In tomatoes, allowing two main stems to develop (don't pinch back the bottom most sucker) also promotes development of leaves that provide shade. You can also try to shade individual fruits that have the most sun exposure with a white or light-colored rag or scrap of fabric (though I cannot attest to this method as I have not tried it). One more tip: if you plant against a light colored surface (a fence or wall), the reflected light may also cause sun scald, so avoid that spot next summer.
Just like you can get too much sun, your plants can too!