15 common problems in your warm-season vegetable garden and how to fix them
Story and Photos by Jeanne Grunert
You’ve diligently amended the soil and waited until the proper time to plant your vegetables. You’ve tended them lovingly, watered them daily, and shooed away crows, deer, and insects.
But the peppers aren’t growing. There’s no sign of the tomatoes and the lettuce bolted. And, in one night, your sweetpotato vines disappeared like magic.
Welcome to the world of the warm-season vegetable garden, where Murphy’s Law – “If anything can go wrong, it will, and at the worst possible moment” – seems to apply.
But never fear – I’m going share 15 of the most common problems fellow gardeners have battled in their warm-season vegetable gardens and provide you with some tips to deal with (or prevent) those problems.
Problem 1: Tomatoes are cracking
Solution: Cracked tomato skin is the result of uneven watering. Tomato plants that survive periods of drought followed by heavy rain absorb all water – sending it to the tomatoes on the vine. The sudden influx of water causes the ripening tomato to swell. The skin cannot expand quickly enough to accommodate that water, and it cracks to avoid bursting. To prevent this, water your plants evenly and do not allow them to completely dry out between waterings.
Problem 2: Lettuce tastes bitter and sends up a big stem in the center
Solution: Your lettuce has gone to seed, or bolted. Lettuce is a cool-season vegetable and sets seed once hot weather arrives. Once lettuce has gone to seed, the leaves have a bitter taste. You cannot prevent bolting, but you can plant heat-tolerant varieties to get the most out of the growing season. Try Romaine, or plant lettuce under tomato plants. The shade may delay them from setting seed.
Problem 3: Eggplant seedlings disappear overnight (or any vegetable seedlings)
Solution: Cutworms are the perpetrators of that type of damage. Cutworms come out at night and munch right through the tender stems of tomato, pepper, eggplant, and other seedlings. The solution is to place “collars” around the stems, denying the worms access. You can make cutworm collars out of paper cupd with the bottoms cut out or cardboard toilet paper rolls. Once the plant has several sets of leaves, you can remove the collar.
Problem 4: Sweetpotato leaves disappear overnight
Solution: It sounds like the deer found your sweetpotato vines. Sweetpotato vines are like candy to deer and they can clean out an entire bed overnight. If you have a fence around your garden, inspect it carefully. Fencing to keep deer out of the vegetable garden should be at least 8 feet high.
Problem 5: Tomato plants are not producing fruit
Solution: You may have planted the wrong variety for your region, especially if you purchased seeds from a catalog. Read the descriptions and zone recommendations carefully. Some tomatoes are highly sensitive to temperature and will not flower if temperatures are below 55 F at night or higher than 85-90 F during the day.
Problem 6: Cuts or bite marks on beets
Solution: Inspect the beets for holes. If you spot holes and the beets show signs of nibbles, the culprits are probably voles, which are rodents that look like field mice. Voles look for shelter near their food source, so remove mulch from around the plants. Fencing buried 12 inches below the soil surface all around the garden will keep out not only voles, but rabbits as well. Harvest beets frequently to avoid tempting the critters.
Problem 7: Funny-looking carrots
Solution: Twisted, stunted, or weird-looking carrots are the result of compacted soil or rocks in the soil. Carrots need sandy loam to have enough room for their long roots. Obstructions cause roots to twist, branch, or form those weird shapes you see. Twisted roots can also mean your carrots were planted too close together. Thin carrots so that they are about 1 inch apart and amend your soil, especially clay soils, with plenty of compost or well-rotted manure before planting.
Problem 8: “Hairy” carrots with too many small side roots
Solution: All carrots have some small white feeder roots, but carrots that look like they’re growing a full head of hair are victims of too much fertilizer or soggy soils. Again, amending the soil before planting is the best way to prevent this; and cut back on fertilizing and watering.
Problem 9: Potato plants attacked by striped beetles
This is the larva of the Colorado potato beetle. It loves potatoes, but will attack any nightshade family plant, including eggplant. Remove by hand and dump it into soapy water to kill it.
Solution: Those beetles are probably Colorado potato beetles, which love plants in the nightshade family. After they’ve destroyed the potato plants, they may move onto your eggplant and tomato plants. You can remove the eggs manually, which is not the most effective method. However, crop rotation, delayed planting, and the use of trap crops and straw mulch have proven effective .
Problem 10: Zucchini the size of baseball bats
Solution: Zucchini can quickly take over your garden if you overestimated how many plants you needed. They grow very quickly, especially during the warm summer days, so pick zucchini twice a day during peak season. Too much zucchini for one family to eat? Donate excess produce to your local food pantry.
Problem 11: Beans never germinate and the bean plants are a no-show.
Solution: Crows probably ate the seeds. Crows love bean, pea, and corn seeds, as do many other birds. Try covering the newly planted seeds with bird netting. You can place stakes around the planted area and drape the netting over it until the seeds have germinated.
Problem 12: Corn stalks look fine, but when you peel back the leaves from the corn to cook it, you find absent kernels and brown patches.
Solution: Small brown moths or insects inside the corn signal corn earworm. Insecticide may be the only way to prevent or treat infected corn. Missing kernels can mean incomplete fertilization.
Problem 13: Soil dries out too quickly, leaving behind droopy vegetable plants.
Solution: It can be difficult to provide enough water to plants during Virginia’s summer heat and drought. Soaker hoses are a good solution. They drip water near the roots of the plants and can be left on while you tend to other garden chores or household tasks. Timers placed on watering systems can also ensure that your garden receives adequate daily water.
Problem 14: Tomatoes have black, flattened ends.
Solution: Tomatoes, squash, and other vegetables with black, flattened ends are suffering from blossom-end rot. This can be caused by uneven watering practices, lack of magnesium and calcium in the soil, or improper pH, which makes it difficult for the plant to absorb calcium, magnesium, and other vital nutrients. Have soil test completed on your vegetable garden soil each spring through your local cooperative extension office and follow their recommendations. Improve your watering practices by adding timers to irrigation systems or simply getting into the habit of watering plants at the same time every day. Epsom salts added to the planting hole around tomatoes can also help by adding trace minerals to the soil; 1 teaspoon per planting hole is sufficient.
Problem 15: You have too many vegetables!
Solution: This is probably the best problem a gardener can have. Many warm weather vegetables can be canned or frozen to preserve the harvest all year long. If you do not know how to can vegetables, many local Cooperative Extension offices provide classes to teach canning techniques and safety. Freezing is fairly easy and instructions can be found online or in various cookbooks to freeze vegetables such as tomatoes, peppers, and green beans. Lastly, you can donate unwanted produce to many food pantries nationwide. Check local town food banks or church food pantries. Many will be more than happy to accept excess produce and distribute it to those who need it.
1. Sablon, Ludovic, Joseph Dickens, Éric Haubruge, and François Verheggen. “Chemical Ecology of the Colorado Potato Beetle, Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae), and Potential for Alternative Control Methods.” Insects. Accessed February 8, 2018. doi:10.3390/insects4010031.
Insects are a problem in many warm-weather vegetable gardens. Squash beetles carry diseases and can ruin many plants quickly. Colorado potato beetles love all nightshade plants, and moth larvae chew holes in cabbage, kale, and broccoli leaves. One great way to prevent insect infestations, rather than treat them with chemicals, is to use a floating row cover or garden fabric to prevent insects from reaching your plants. Such fabric is permeable and allows both sunlight and water to reach the plants without allowing insects through. Check your local garden center or your favorite mail order catalogs for this special fabric.