15 problems solved in your warm-season vegetable garden

Story and Photos By A.J. Heinsz-Bailey

Every day there are changes in your vegetable garden. Along with these changes – temperatures, rainfall, insects and diseases – problems arise. The warm-season vegetable garden is a living entity that requires constant supervision to produce positive results (groceries). It is usually a labor of love, but often it becomes a battleground. Take the gloves off, get your hands dirty, and fight to overcome the odds and produce a perfect vegetable. 

Be patient – most of the time there is a way to resolve the issues if you use a systematic approach to diagnosing the problems. Don’t get discouraged: Get information. Your local cooperative extension agent is a great resource for research-based information.

1. What varieties can I plant in my area?
LSU cooperative extension has a free downloadable booklet, Vegetable Planting Guide, at that recommends vegetable varieties for our area. The United States Department of Agriculture has a website devoted to the plant hardiness zones. Louisiana covers Zones 8a, 8b, 9a, 9b, and 10a. You can also ask your local nurseries and feed stores for their favorites.

Marigolds (Tagetes spp.) do not really have pest-fighting abilities. Make sure your information is research-based. The cooperative extension service is a great resource.

2. When can I start planting in the spring? 
Start planting around March 15. This is the average last frost date in the southern part of the state, one to two weeks later if you are in the northern part of the state. Row covers and black plastic can be used to protect seedlings from unexpected frosts.


3. Why aren’t my seedlings germinating? 
Seeds need time to germinate. This information is usually found on the seed package. Another reason may be that the soil temperature is too low. 60-65 F is the minimum temperature. Use a soil thermometer to check – if it is too low and wet in the seedbed, the seeds will rot and not germinate. Other causes of poor germination are soil that is too dry, birds or animals eating the seeds, or the seeds could be too old. Using row covers and replanting with fresh seeds will solve these problems.

Crushed eggshells add calcium to the soil and deter soft-bodied pests, such as slugs and snails.

4. Why are my young plants dying? 
In early spring, cold damp soil a fungal disease called “damping off” could be the culprit. You might have to sow the seeds in a sterile seed-starting mix until the ground warms up and dries out. Fertilizer burn will cause young plants to wilt and fall over dead. Wait two or three weeks before fertilizing young plants. This gives them a chance to develop roots and become established. Use a weakened water-soluble fertilizer if necessary.


5. When and how do I water? 
The amount of water that your garden needs depends on the weather conditions in your area. During the summer, water thoroughly and deeply each time and to allow the soil dry out before watering again. Deep watering allows the plants’ roots to grow deeper, where they are less likely to dry out. Light surface watering is a waste because the water never reaches the root zones of the plants, and the moisture rapidly evaporates from the top inch of soil. The best way to tell if your plants are receiving enough water is to take a trowel and dig down a few inches. The soil should be moist at least 3-4 inches deep. Try to do your watering in the morning so that the leaves can dry off a bit before the hot sun hits them. Evening watering is sometimes acceptable if the temperatures are warm enough to ensure that the foliage is dry before the temperature drops at night. Wet foliage leaves the plants more susceptible to fungus and disease.

Toilet paper rolls are an effective, organic way to protect new transplants from cutworms.

6. What vegetables can I grow in a container? 
Vegetables that have a compact growth habit are best suited for growing in containers; 2-5 gallons is adequate for good root development. Radishes, tomatoes, bush beans, bush cucumbers, eggplant, peppers, potatoes, okra, and green onions are all great options.


7. Why are the leaves turning yellow? 
Poor drainage and too much water will result in yellow leaves. Don’t overwater and improve the drainage. Try planting in raised beds. Nutrient deficiency can also cause yellow leaves. Apply fertilizer or organic matter around base of the plants. Have the soil tested every two years. Know that lower leaves will naturally turn yellow as they age.

Soaker hoses and adequate spacing between rows make this vegetable garden easy to water and weed.

8. What should I use for mulch and why? 
Mulch is a protective covering placed on top of the soil and is used to keep weeds out and moisture in. Biodegradable mulches – leaves, straw, compost, grass clippings – are used because they decompose into soil-building organic matter.


9. How do I keep squirrels and rabbits out of the garden? 
Protect your garden with fences, row covers, or netting. Cayenne pepper spray can be used as a repellent. Electric fencing also helps deter these voracious eaters.


10. When is the best time to pick my vegetables? 
The best time to harvest is in the morning, right after the dew has dissipated. The time of day you pick your vegetables affects the taste and storing quality. Vegetables harvested in the morning are crisper and juicier than those picked during the heat of the day. At night, vegetables replenish the moisture they lost during the day. Sweeter vegetables use the nighttime hours to make sugars from the starches they produce during the day.

Wire hog panels support vining crops. This type of trellising provides good air circulation and requires less space.

11. What is the powdery white coating on the top of my squash leaves? 
This coating is a fungal disease called powdery mildew, which occurs when the leaves are dry and the weather is humid. Proper plant spacing ensures good air circulation, which lessens the opportunities for the disease to manifest. And don’t forget that there are disease-resistant varieties.


12. How do I get red ants out of my vegetable garden? 
Drenching a mound with 2-3 gallons of almost boiling water eliminates ant colonies about 60 percent of the time, but it will also kill any plants it comes in contact with. Some home remedies, such as applying instant grits, molasses, aspartame, or club soda to ant mounds, do not work. Soapy water is around 60 to 70 percent effective. Hot or soapy water may kill only a portion of the colony or cause it to move. One method currently being evaluated, and showing positive results, is drenching the mound(s) with a mixture of dishwashing liquid and citrus oil. Spinosad has been labeled safe for use in vegetable gardens. Always read the label on any chemical before using it in your vegetable garden.


13. My plants are dark green and healthy but they do not have fruit.  
Too much nitrogen will give you gorgeous dark green plants … with no fruit. Avoid excessive fertilizing.

A properly spaced, weed-free vegetable garden will ensure healthy productive plants … and an abundant harvest.

14. Why do the leaves look shredded and have holes in them? 
The most common causes of leaf damage are insects, slugs, birds, and rabbits. Abiotic causes of leaf damage include hail and wind. Row covers, bird netting, and proper use of insecticides are all effective controls. Before using any insecticide it is imperative to properly identify the insect pests.


15. Why are my tomatoes and peppers rotting on the end? 
Blossom-end rot is caused by irregular watering, which prevents the plants from obtaining and/or effectively using nutrients. A stretch of dry weather followed by excessive rain can also cause rotting ends.


Changes occur every day in the vegetable garden. Daily inspection allows you to notice problems before they get out of control. Prevention and early detection are the most important tools for problem solving. Identify the plant, note what part of the plant is affected, take pictures, note the soil conditions, identify the insects, and use reliable sources of information to determine a solution.

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