What to do about basil leaves turning yellow and other common problems
Why are my basil leaves turning yellow, and what can I do about it? Unfortunately, there are a few possibilities here, and it can be challenging to pinpoint the problem. If you’re lucky, it’s just a matter of overwatering. Take a break from watering the basil, and you should see the plant perk back up.
Nitrogen deficiency is also an occasional issue. The only way to be sure is to test your soil, but the cure is to fertilize your basil plant, so it gets the nitrogen it needs.
There are also some diseases that could cause basil leaves to turn yellow.
- Downy mildew: You may see yellowing leaves or dark, discolored patches on the plant. Keeping the leaves dry and ensuring good air circulation may prevent this problem before it starts.
- Fusarium wilt: This soil-borne disease may be one cause of yellowing leaves. It’s also highly contagious and will wipe out your garden if given the chance. If you spot this issue, the best thing you can do is to pull up your basil plant and throw it in the garbage before the disease has a chance to spread.
- Root rot: Since the plant roots are below the surface, root rot can be tough to diagnose, but overwatering is, again, a primary culprit. Once the season is over, look at ways to amend the soil or adjust the landscape so there is better drainage.
Besides your basil leaves turning yellow, what other common basil problems might you see?
Aphids, whiteflies, Japanese beetles, and spider mites are all fond of basil. A neem oil spray is generally effective against these pests. Slugs enjoy basil, too. Sprinkle a little diatomaceous earth around your plants, and that should take care of the problem.
Doug the Cook