Why The Fruit From Your Lemon Tree Looks Lumpy And What You Can Do About It

If your formerly beautiful lemons have suddenly become lumpy, bumpy, and just plain ugly, a fungus called "lemon scab," or verrucosis, is probably to blame. While the word fungus is scary, lemon scab is a skin deformity, so it's still safe to eat your lemons. They simply won't look as pretty as they did before. If you prefer aesthetic lemons, the good news is: it's fixable! Whether you're growing your lemon tree indoors in a pot or outdoors in your garden, you can treat your trees to get rid of the fungus.

If you think your trees may be infected with lemon scab, your weather may be partly to blame. Lemon scab thrives in warm, moist climates, such as in portions of Florida and other parts of the United States. When it gets wet, the fungus produces spores, which are spread by the wind, rain, and even your sprinkler system. Once these spores land on your tree, they can infect leaves and immature fruit, changing how your lemons grow. This produces unsightly, bumpy lemons that may even be discolored, with pinkish or gray scabs.

You can take steps to keep your trees healthy and less vulnerable to fungus. Making sure your trees get adequate water around their roots, especially during hot, dry seasons, can help. It's also important to fertilize your lemon trees in the spring and fall to make sure your trees stay healthy and nourished. If your lemons look deformed, it's possible your soil isn't providing the nutrients your trees need, making them more vulnerable to fungus. Your soil needs the right balance, and bumpy lemons are often getting too much nitrogen and not enough phosphorus. You can look for a fertilizer that is rich in phosphorus — such as Farmer's Secret Fruit Tree Booster Fertilizer or Down to Earth Organic Citrus Fertilizer — or ask for recommendations at your local nursery.

After you've harvested your crop of bumpy lemons, you can treat your tree to make sure your next harvest is free of lemon scab. A copper protective spray — such as Southern Ag Liquid Copper Fungicide, available on Amazon — will protect your tree. You will need to spray every bit of your tree: its bark, both sides of the leaves, and all flowers. Be sure to wear long pants and gloves to keep the copper mixture off your skin and protective eyewear. You'll want to keep an eye on your tree as it grows, as the growing fruit will cause gaps in your protective copper coating. You may need to spray two or three times during the growing season. Then, the next time you harvest your lemons, your fruit should be beautifully aesthetic again.