QUESTION: Why are my eggplant leaves turning yellow? Is the plant in trouble? – Emily L
ANSWER: There are several different reasons for eggplant foliage to turn yellow. We’ll explain the other symptoms for each reason so you can identify the problem with your eggplant plants, and we’ll also tell you what to do to address each problem. Just keep reading to learn the problem behind your eggplant foliage discoloration and what to do about it.
Have your plants recently gone through cold temperatures? Although the leaves will show immediate signs of damage, the eggplants themselves may not start to show symptoms for between five and seven days. Eggplants are more susceptible to cold damage than tomatoes or peppers.
Other signs of cold damage include leaves that turn yellow and look soft or water-soaked, then gradually turn black. The surface of eggplants that have sustained cold damage has a bronzed appearance. Inside the eggplants, the seeds or the fruit may have turned brown. Like the leaves, the fruit will develop a water-soaked appearance before rotting.
There is unfortunately nothing you can do to help a plant that has sustained cold damage. All you can do is take steps to prevent cold damage before it happens. Move delicate plants like eggplant indoors or to a sheltered spot like a patio or shed before cold weather rolls in. There are other options, too. To find out more, check out our article How to Protect Plants in the Winter.
In order for Phomopsis blight to turn leaves yellow, the infection must be severe. Leaves will be torn, discolored, and will wilt before they fall from the plant. You’ll see dark, sunken lesions on stems just above the soil. In addition to their discoloration, leaves may develop circular lesions that may be gray or brown with a lighter center. Eggplants will show pale, sunken, oval spots that have concentric rings of tiny black dots.
Once you’ve identified Phomopsis blight in your garden, there is nothing you can do to save the affected plants. Limit the spread of the disease by removing and discarding any plants that show signs of the disease. Do not use these plants in compost, or you risk spreading the disease when the compost is used.
To prevent Phomopsis blight, use resistant varieties of seed whenever they are available. Where eggplant is grown, use a crop rotation of three years or longer. Once eggplants are harvested, use deep plowing to destroy any remaining residues of the blight and prevent it from overwintering in the garden.
Do what you can to prevent an overly moist environment, which encourages lots of plant diseases. Make sure to water plants at their base only, avoiding splashing the water onto foliage or watering the soil far from the base of plants. Plants can only take in water through their roots, so moisture that splashes their leaves or is too far from the plant base won’t be taken in and used. The excess moisture on leaves will also promote fungal disease and Phomopsis blight. Make sure that your plants are spread far enough apart in the garden for air to circulate between them and prevent excess moisture.
Spider mites are teeny tiny insects that can be all over a plant before you know it. Where they feed, the underside of leaves turns a russet color while the tops turn yellow, and in addition to discoloration, the leaf shape can become distorted. Where the problem is heavy, you may see webbing on the underside of leaves or the insects themselves crawling on your eggplants.
One strategy for fighting off spider mites is simply to hit them with a jet of water from a high-pressure hose. This will wash off the insects and any webbing they’ve created. You may need to use this treatment repeatedly in order for it to be effective.
For more information, see our article 5 Methods to Control Spider Mites.
When plants are infected with verticillium wilt, the edges and tips will turn yellow first. As time passes, the whole leaf will eventually turn yellow and wilt. Lower leaves will be affected first, and it’s common for only one side of the plant to be affected. If you take a lengthwise cut of the stem near the surface of the soil, you’ll see that the center is green.
It’s best to stop the spread of the disease by removing and discarding any affected plants. Do not use these plants in compost, or you risk spreading disease when the compost is used. Verticillium wilt often remains in the soil once affected plants are removed, so don’t grow eggplants or other susceptible crops in the spots where affected plants were grown.
Viruses can cause eggplants to have leaves mottled with discoloration as yellow and light green areas appear. Leaves may be curled or formed long and thin. Eggplants will have yellow blotches or brown rings, and the growth of affected plants may be stunted.
There is no cure for plant viruses, so if you suspect a virus is the root cause of your eggplant’s foliage discoloration, all you can do is remove and discard it. Do not use diseased plants in compost, or you may spread the disease along with the compost when it comes time to use it.
Now you know the reasons why your eggplant plant’s leaves could have turned yellow. Use the other symptoms to nail down exactly which problem your plant is struggling with, then follow the steps listed to deal with the issue. Your garden will be back to perfect in no time.