A website from UGA Cooperative Extension

Well summer officially starts on the 20th of this month, but it already feels like the middle of August.  We had several days in the 90’s last week and it looks like we will remain in the upper 80’s to 90’s for a while.  Couple this with a severe lack of rain and you have conditions that are only favorable to a cactus.  We may have the opportunity to start getting some afternoon showers if this tropical system can bring moisture this far north. 

One question that I should start getting from gardeners soon is, “why are my vegetables not producing?”  The simple answer is the weather, but there are a few different reasons for the poor production.

To begin with we must realize that pollen is a living thing.  It is not just a small particle that covers your vehicle or makes your eyes watery and causes sneezing.  It is basically the male reproductive cell of a plant.  Just as we don’t last out in the heat too long, pollen doesn’t either.   Different pollen can survive different temperatures, but the majority does not perform well or live long at the type of temperatures we have been experiencing.

For example, we know that crops like tomatoes do not set fruit when nighttime temperatures exceed 75.  Most of our legume crops react the same way.  Things like snap beans and butter beans do not like high temperatures either.  They will flower all summer long, but when temperatures are too high the flowers fail to pollinate and fall off. For more information on pollination click Here.

Another problem related to the heat and drought is blossom end rot.  As I have stated in past articles this is the result of a calcium deficiency that is usually brought on by drought stress.  The result of this deficiency is black sunken areas on the blossom end of many of our vegetables like tomato, pepper, and most cucurbits (i.e. watermelon and squash). 

To reduce this watering should be done fairly consistently to ensure a steady supply of calcium from the soil.  Calcium sprays can help a little, but the best approach is to have plenty of calcium in the soil and if needed add gypsum to supply extra calcium during the growing season.

With the temperatures and drought that we are experiencing irrigation is required not only to produce some vegetables, but just to help our plants survive until cooler temperatures and rainfall come to the rescue.  Maybe these much-needed showers and clouds will give everyone’s wells a break and give your veggies a much needed boost. If you have questions or comments contact your County Agent.

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