How to treat lemon tree dropping fruit?

rbaus

Hi guys,

I am trying to find what's wrong with our lemon tree, the lemons are half the original size now (since last year). I have no idea how to care for it so trying to understand what can I do. I also see a lot of lemons just falling on the ground. I have been watering it daily in the evenings though.

The caterpillar (I think) in the first photo is the only sighting I can see, haven't seen any more of those.

Any advice would be greatly appreciated.

MitchellMc

Hi @rbaus,

A lemon tree that drops fruit and produces smaller lemons is usually experiencing stress. One of the most common causes is watering the tree too frequently. Watering every evening keeps the soil too wet, which can stress the roots and make the tree drop its fruit early. Lemon trees grow best when they receive deep but infrequent watering. It is better to water two or three times a week for 10mins during warm weather and to always water in the morning so the soil can dry out during the day.

Another major cause of small fruit is nutrient deficiency. Lemon trees are heavy feeders and need regular fertilising to grow full-sized lemons. When nutrients such as nitrogen, magnesium, and potassium are lacking, the tree will often produce smaller fruit and drop developing lemons. Using a citrus-specific fertiliser from spring through early autumn helps correct this. Adding a small amount of Epsom salts occasionally will also improve leaf colour and fruit size.

The caterpillar you found is likely a citrus swallowtail caterpillar. These caterpillars look large and alarming, but they rarely cause serious damage to the tree. If you only see one or two, you can simply remove them by hand. They are not usually responsible for fruit drop.

Environmental conditions can also cause lemons to fall early. Wind, heat stress, compacted soil, and inconsistent watering all contribute. Adding mulch around the base of the tree helps keep the soil evenly moist and cool. Just make sure to keep the mulch a short distance away from the trunk to prevent rot.

With better watering habits, consistent feeding, and a bit of pest monitoring, your lemon tree should begin producing larger and healthier fruit within several weeks.

Here's a helpful guide: How to grow and care for citrus.

Please let me know if you have any questions.

Mitchell