If you notice that the leaves on your basil plant are turning brown, do not waste any time; start figuring out the cause and taking care of the problem.
The most common reasons for your basil plant turning brown are overwatering, underwatering, getting too much or too little light, becoming rootbound, changes in temperature, pests, stress, and disease.
To learn more about why your basil plant is turning brown, keep reading.
Causes of basil leaves turning brown
Basil plants are one of the easiest plants to grow, especially for beginners. They are very popular plants because they serve a dual purpose: they can be beautiful indoor plants, and their leaves can also be used in multiple types of cuisine.
Even though they are easy to grow, they are quite sensitive to changes in their living conditions, which is why you should always be on the lookout for possible problems with your basil plants.
The following are the most common causes of browning basil leaves:
The plant is overwatered
A common mistake made by many home gardeners is overwatering their plants, and the popular basil plant is no exception. Overwatering can lead to root rot which, when it reaches the stem and leaves, can cause them to turn yellow and eventually brown.
Yes, basil plants like their soil moist, but never water to the point that it becomes boggy. This problem is doubled if the basil is planted in a container that does not have any drainage holes at the bottom.
Overwatering is more common for basil plants that are kept indoors because they do not have the heat of the sun to help evaporate excess water from the soil.
If you suspect that your basil is overwatered, check its roots to see if they are brown, soft and mushy. If they are, then they are rotting and you are definitely overwatering the plant. If you were able to catch the root rot in its early stages, you can salvage the plant by removing any dead roots and planting it in new soil.
The plant is underwatered
Basil likes its soil to be perpetually moist, but not boggy. If you fail to keep up with its water needs, the plant may dry out. Its leaves will shrink, curl, and turn brown. This will happen even faster if the plant is underwatered and also kept near a window that gets plenty of sun. The leaves of an underwatered basil plant will also have an unpleasant and bitter taste.
Basil does not really follow a strict schedule of when it needs to be watered. You simply need to look at the plant and if the leaves are looking a little droopy and the soil is no longer that moist, you can spritz it with some water from a fine mist spray bottle.
The plant is not getting the required amount of light
Basil plants like to get between six and eight hours of sunlight a day. If the plant is placed under direct sunlight, it should not get more than four hours of exposure.
If a young plant is placed in full sun, it can dry up and burn, but mature plants often do well. If a plant does not get enough sun, its leaves will turn yellow and curl up. The plant will also tend to have a longer stem because it will try to compensate and grow toward the nearest source of light in desperation. Be perceptive and know when your plant needs sunlight, and simply move it to a sunnier location. If the lack of light is due to the season, such as winter, you may need to buy a grow light for your plant. Basil plants will need 12 hours of exposure to artificial light in order to simulate the effects of six hours of natural sunlight.
The plant is rootbound
Another reason your basil plant may be turning brown is due to its container being too small. A plant’s roots need space to grow in order not to suffocate. A plant’s root system becomes rootbound if the roots keep growing in a circle around themselves.
You can tell a plant is rootbound if you can see the roots grow forcibly out of the drainage holes at the bottom of the pot, and if the soil tends to dry out very quickly even if it has just been recently watered.
The only way to remedy a rootbound basil plant is to repot it in a larger container. You do not need to loosen the roots when transferring the plant, because this could damage the plant. The roots will do the untangling themselves as they grow into the soil.
The plant is affected by changes in temperature
If a basil plant is left out in the cold, its leaves can turn brown and become deformed. Remember that the natural habitat of the basil plant is tropical. It does not do well if the temperature gets anywhere below 50 degrees Fahrenheit. You can save the plant by taking it indoors to a warmer location and only putting it out again once the weather becomes sunnier.
The plant has pests
Pests such as scale insects, thrips, spider mites, and aphids can cause a basil plant’s leaves to turn brown because they suck out the plant’s juices. Be sure to check your plant for pests every once in a while, especially when you start to see some discoloration. You can use insecticides to save your plant from these insects.
The plant is diseased
The basil plant can suffer from a multitude of fungal diseases that can cause its leaves to turn brown. You can try to save the plant with a fungicide, but if it is afflicted with verticillium wilt or fusarium, that usually means a death sentence for the plant.
The best approach to fungal diseases in basil plants is to prevent and avoid them completely. Try not to overwater the plant so that it is not perpetually damp. If you suspect verticillium wilt or fusarium, it is best to dispose of the plant immediately so it does not affect any neighboring plants.
The plant is stressed
Basil plants may be hardy, but they do not like being overhandled. Avoid repotting them too often because they may go into shock, turning the leaves yellow or brown. Give your basil plants enough time to adjust to any changes in their living conditions, such as temperature, light or watering.
Conclusion
A basil plant’s way of showing discomfort regarding its growing situation is through curling, wilting, and discolored leaves. When you see these changes in your basil plant, make sure you identify the problem as soon as possible in order to remedy it and have a chance at salvaging the plant.
It is your responsibility as an owner to know your plant’s water, sunlight and care needs so that it grows as healthily as possible. The healthier your basil plant is, the more productive it will become for you.
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