Common garden problems show up annually in summer

Published on Wednesday, 10 July 2013 22:45 - Written by By Keith Hansen Keeping It Green

I was amused at a recent comment on a gardening Facebook page. She was saying how much different is to grow plants in Texas than where she came from (up north somewhere). Something to the effect that you could just spit on the ground and plants would grow. Well, welcome to Texas. Even though our area of Texas is one of the best for gardening (in my opinion), we still have our share of challenges. Here are some common questions we get during the summertime.

VEGETABLE GARDEN

Q. My yellow summer squash is not yellow — it’s green!

A. Your squash plants are infected with a virus that is transmitted by aphids. All it takes is one feeding by an aphid carrying the virus and the disease is transmitted to the plant. Besides turning the squash warty and spotted with green, it can decrease the general health of plant, thus reducing yields. The fruit, however, is still okay to eat. One thing is for sure, the squash has not cross-pollinated with cucumbers, watermelons or cantaloupes, as is often believed and blamed for the green squash.

Q. My tomatoes are not ripening.

A. This problem is due to heat stress. As the temperature gets in to the 90s, the plant’s internal biochemical reactions needed to produce the pigments that give tomatoes their color are greatly reduced, slowing down the ripening process. If you see any hint of color on the shoulders (area where they are attached), you can pick them and ripen them indoors in the dark. They will turn red more quickly, and should be just as tasty. Do not put them in the refrigerator because that will decrease their flavor. They do not need light to turn red.

Q. My tomatoes and green beans are not setting fruit.

A. This is also caused by high temperatures. As temperatures climb into the 90s, these plants stop setting fruit, even though they may still be producing flowers. Cherry tomatoes seem to set fruit better under hot conditions than large-fruited types.

Q. My tomato plants look like they are burning up; the leaves turn yellow then brown.

A. Most likely spider mites are feasting on the foliage. Mites are very small, but you can detect them by rubbing a leaf on a white sheet of paper. Tiny reddish streaks indicate mites. When they are really bad, you will see fine webbing. At that point, it is best to start over. Find a new spot, find some fresh transplants, and plant for a fall harvest. Now is the time!

Q. I want to plant pumpkins for Halloween. What is that fastest maturing variety?

A. Now is the time to plant. Depending on variety, pumpkins can take between 75 and 120 or more days to mature. Look for varieties with the shorter time-to-maturity. In general, the smaller varieties are ready sooner than the large types. Give them good soil moisture as they have shallow roots and will stress easily if subjected to dry conditions.

LAWN QUESTIONS

Q. My St. Augustine grass is turning yellow, then wilts and turns brown.

A. Chinch bugs are a frequent summer pest of St. Augustine. They typically get started in stressed, hot, dry areas of the lawn as near the sidewalk, driveway or street. Although they are not the only possibility for this kind of symptom, chinch bugs are the first thing to suspect if the grass appears to need water, yet remains wilted and eventually dies.

The other cause for dry spots in the yard is from lack of water. Sprinkler heads may be misaligned, partially plugged, or have low water pressure, resulting in “hot spots” appearing in the yard. These manifest during prolonged dry spells. Test for soil moisture in the brown areas with a spade or shovel (it will be harder to push the tool into the soil). Check the output of the sprinkler heads by collecting the irrigation water in cans in both the dry and green areas and compare the accumulated amounts. Don’t rely on your eyes to determine how much water is falling on these areas.

TREE QUESTIONS

Q. I need a small tree for a very hot, sunny location

A. One of the best types of trees for this situation is crape myrtle, and right now is a great time to select them based on color. I have seen containers with more than one color, a result of multiple cuttings used to create a multi-trunk specimen but getting a second variety mixed in. I have also seen miss-named varieties (color of bloom does not match the varietal description). Keep in mind that there are many different varieties, each with different characteristics besides flower color. Some can get 30 feet tall at maturity; others may only grow 12 feet tall. Do your research before making a final selection.

Keith Hansen is Smith County horticulturist with the Texas A&M AgriLife Extension Service. His web page ishttp://EastTexasGardening.tamu.edu . His blog ishttp://agrilife.org/etg .