A lot of pests and diseases are out there, and it is not unusual to have white spots on citrus leaves. In this guide, I will tell you how easily you can identify the reason behind the white spots.
Note: Not all the white spots are because of the same reason. My goal is to give you simple and easy-to-spot signs to help identify the cause behind the white spots.
In most cases, spider mites are the main culprit. But there are other possible reasons like citrus leaf miner, fungal or bacterial infection, and honeydew from aphids.
Please don't get confused, as they all cause different types of white spots.
Let me start with the most common reason first.
White spots or dots on citrus leaves due to spider mites
The picture you are seeing at the top of this article is a spider mite-affected citrus tree.
If you see white dots all over the leaves or most of the parts are covered with those small white dots, that must be due to the spider mite attack.
Once you confirm your citrus leaves are affected by spider mites, it's time to cure them.
Note: You might notice yellowish dots as well.
You may tap a leaf over white paper to spot mites.
Treatment: Spray insecticidal soap or horticultural oil on the leaves.
I have heard people say "spray it in the early morning or late afternoon". But here's my personal tip: Try to avoid spraying in the early morning. As the temp. will rise, it may cause leaf burn due to sunlight.
I prefer the evening time, as the insecticidal soap will get enough time to act. (Overnight)
Wash off the leaves the next morning.
Try it for 3 days, and it will work.
After rain or watering, you might notice white spots on your citrus tree leaves caused by water mixed with soil residue. No need to worry—just rinse them off with clean water.
White spots due to leaf miner
If you see white lines or tunnels on your citrus leaf, it must be due to leaf miners.
Here's what it looks like:
I have created a separate dedicated article on this:
Leaf miner on citrus <- How to get rid of it.
You may also notice that the leaves are curling like this:
Tip: If you find white mold on the citrus leaves, just remove those leaves and then spray fungicide.
If you leave your lemon tree untreated, the white spots will spread all over your plant within a few days. It might look like this:
It might take less than 2 minutes to read this guide, but the solutions and reasons I explained are from years of my gardening experience. To help me write more on plant diseases and treatments, subscribe to this site.
