Lemons are one of the most popular citrus fruits out there, and the creation of dwarf cultivars has made it possible for lemon fans to grow their own fruit in colder climates.
However, lemon trees are known for being a bit temperamental when it comes to sudden changes, and leaf drop is a common problem with these plants.
Whether you’re an experienced grower or this is your first lemon tree, sudden leaf drops can catch you off guard.
Just what’s causing the drop, and how do you solve it?
Lemon Tree Losing Leaves? (How To Save It?)
The good news is that it’s not the end of the world if your lemon tree begins dropping a few leaves.
Most of the problems that lead to leaf drop can be traced back to basic care issues, which can then be remedied.
Lemon trees need a lot of sunlight to thrive, equating to a minimum of 8 hours of full sun per day, preferably longer.
This is one of the first places you should look when your tree starts to lose leaves.
A potted tree can simply be moved to somewhere with more light, but those in the ground may require more drastic measures, such as pruning back any obstructing trees or transplanting the lemon tree to a sunnier spot.
Infections And Infestations
Several potential diseases can result in leaf drops, such as:
- Alternaria leaf spot
- Greasy spot fungus
The latter causes a reboot rot, while the other two directly attack the foliage.
These diseases can be prevented using disease-resistant cultivars or regular doses of neem soil soak to help the plant’s natural immune system.
However, you may need to use copper-based fungicides or other chemical solutions once these diseases hit.
Likewise, a whole host of pests might start feeding on your tree.
Aphids, mealybugs, and similar pests are generally less destructive than caterpillars or grasshoppers, but all of these will harm your tree to some degree.
Regular treatments with a neem soil soak can help prevent infestations of chewing or piercing insects without harming beneficial insects.
However, due to the size of even small trees, you may need to resort to chemical pesticides if an infestation has taken hold.
Citrus plants are adapted for warmer zones and don’t handle the cold like some other plants, although they fare pretty well in hotter conditions.
Lemon trees will suffer if the temperature drops below 50° degrees Fahrenheit, and many will lose leaves.
Some cultivars can handle much lower temperatures, dropping leaves only when the temperature drops below 32° degrees Fahrenheit, but that doesn’t mean the plant won’t have some problems in slightly warmer temperatures.
As a general rule, try to move any potted lemon trees indoors if you suspect the temperature will be dropping, but keep in mind the tree will suffer some shock when you do so.
It might come as a surprise, but trees need more than a simple N-P-K blend.
In fact, your lemon tree needs 16 different nutrients to remain healthy.
Deficiencies of the following can all lead to leaf drop:
Avoid using fertilizer tree spikes for these plants and instead, stick with a quality citrus fertilizer blend to ensure the plant is getting what it needs.
Poor Watering Habits
Improper watering is perhaps the single greatest reason plants get sick, yet it’s one of the easiest to avoid.
It might seem counter-intuitive, but the older your lemon tree gets, the less water it needs.
This is because the root system spreads out and can draw moisture from much deeper into the ground.
Younger plants will have less reach, so they’ll need watering more often.
Potted plants will generally need to be watered when the soil feels dry 2″ to 4″ inches down, with older trees can handle up to half the container being dry before watering.
You can follow a similar pattern for outdoor trees by watering when it’s dry 2″ to 4″ inches down for the first 2 to 3 years, then dry 8″ to 9″ inches deep for the next few years.
For those who prefer a bit more guesswork, keep an eye on the weather forecast and water weekly for the first 3 years, every two weeks for the next 3 years, etc.
One important thing to keep in mind is that you shouldn’t do light waterings.
Ensure the soil is well-draining and saturate it with each watering so that the water will properly drain down to the lower roots.
Sudden Environmental Changes
This last factor will usually only affect potted lemon trees.
When you bring a potted tree indoors or move it to another room, the sudden change in light, temperature, and humidity can shock the plant.
Likewise, you will need to repot the tree every few years, leading to transplant shock.
There’s not a lot you can do about these instances, and the tree will bounce back once it acclimates.
Some helpful tips for reducing the intensity or duration of shock include:
- Always add fresh potting soil when repotting.
- Always ensure the tree is getting the best light, no matter where you move it.
- Always transplant the tree to a place with a similar environment, so there’s less shock.
- Never fertilize right after repotting.
- When bringing the tree outside, harden it by bringing it out for a few hours, then add a few more hours each day for around a week to make a move more bearable.
These simple tricks can reduce the number of leaves lost during transplant shock and allow the plant to get used to its new setting faster.