Why Are My Lemon Tree Leaves Falling Off?

Leaves falling off a lemon tree can be your biggest nightmare if you are growing a lemon tree for the very first time. Let us look at the reasons and tips to fix the falling leaves of the Lemon tree. 

Lemon tree leaves can fall off due to cold, disease, lack of nutrients, overwatering, incorrect soil, and lack of sunlight. 

Premature falling of lemons fruits is not uncommon. However loss of leaves is not common and can be considered worrisome.

It can’t mean anything good and needs immediate solving for the sake of your lemon trees. 

Here are all the reasons that can cause the falling of the lemon tree leaves. 

#1 – Cold

Lemon trees do not take well to cold and frosty weather. There are some cold hardy lemon tree varieties available but they are only cold-tolerant to some extent.    

During winter, staying alive becomes a difficult task that induces stress in the lemon tree.

Other plants overcome winter through dormancy. However, lemon trees have trouble doing this when they have flowers or partially-developed fruits drawing energy.  

To keep the fruits and flowers on the tree, you may have to make a choice between foliage and flowers. As a result, leaves may begin to fall off, a clear sign of stress and limitation of resources. 

Tips to Fix

When temperatures recede to 27℉ (-2℃) or below, lemon trees will require protection. 

You can protect your lemon tree by covering it with a breathable fabric.

Or, a better option, if possible, would be to bring your lemon tree indoors. Temperatures indoors rarely plummet to the temperatures that make lemon tree leaves fall off. 

Read this if your lemon tree leaves are turning brown? 

#2 – Disease

Plants are not immune to disease. A diseased lemon tree could exhibit a range of symptoms that go unnoticed until they become too severe.

Discoloration of leaves, poor fruit, and falling off of leaves are sure signs of disease in lemon trees.

Immediate identification and resolution of the cause are crucial. Neglecting the matter could result in an almost bare lemon tree.

Here are a few diseases of lemon trees that can affect leaves, some of which are pest-related 

a.) Alternaria leaf spot

If you grow rough lemon, Alternaria leaf spot is a common disease that affects this lemon. Caused by the fungus Alternaria alternata, a toxin produced by the fungus will rapidly waste away citrus tissue. 

The infection starts off with colorful leaf lesions that are halo-shaped. But with time other symptoms such as leaf drop, premature fruit drop, and possibly the wilting and dying of shoots and buds! 

b.) Greasy spot fungus

Infections of greasy spot fungus appear as small clusters of yellow on the upper surface of lemon leaves.

With time they turn brown and look like oddly shaped blisters with a greasy texture. By this time the lesions spread to the leaf’s underside as well.

The leaves begin to drop and this leaves the lemon tree increasingly vulnerable to extreme weather (cold) and pests. 

13 Problems of Growing Lemon Trees in Pots + Solutions to Fix Them 

3.) Phytophthora 

The presence of Phytophthora in the soil is dangerous. It starts by affecting the core of the lemon tree, the roots.

After inducing root rot other symptoms are revealed. Leaf fall, fruit fall, dieback, and eventually death can be observed as the fungus progresses. 

The solution to Leaves falling Off Due to Diseases 

Take a closer look and inspect your lemon tree at regular intervals, especially when ill effects are noticed. 

Upon discovering a disease, try to remove the infected parts to prevent it from spreading. Greasy spot fungus can be managed by spraying with copper fungicide.

For Phytophthora, aerating, improving drainage, and keeping soil free of weeds and mulch. 

Ants can be a disease starter when aphids are involved. Get rid of ants on lemon trees with these methods.

#3 – Nutrient Deficiencies

Lemon trees are not the lightest of feeders! Severe nutrient deficiencies will influence a lemon tree’s growth or lack of. Falling leaves can be caused by too few nutrients to support their growth and retention. 

Nutrient deficiency is mostly observed in potted lemon trees.

This is because there is a fixed amount of soil which means limited nutrients. If left without a change of soil and fertilizer, the lemon tree will exhaust the available nutrients. 

The nutrients in question are:

  • Iron (Fe)
  • Manganese (Mn)
  • Magnesium (Mg)
  • Nitrogen (N)
  • Zinc (Zn)

The solution to Leaves falling Off Due to Nutrient Deficiency 

Lemon trees less than seven years old need constant feeding by fertilizer. A gap of six weeks between fertilizing efforts will be just what a lemon tree needs. 

When it comes to potted lemon trees, make sure to give them a larger pot that holds more soil. Even then you’ll find you have to provide them with a citrus-specific fertilizer.

But, be sure to not over-fertilize. It’s not a bad idea to research what the signs are! 

Check Out – Do Lemon Trees Grow All Year Round?

#4 – Overwatering

Like any other fruit-bearing tree, lemon trees need adequate amounts of water. What it doesn’t need is wet soil!

Saturated soil can easily bring about root rot, the decay of roots due to too much water and not enough air. 

Once root rot sets in, it affects the roots and prevents them from carrying out their functions. In turn, the effects show through discoloration and loss of foliage. 

The solution to Leaves falling Off Due to Overwatering

Lemon trees need more water during hotter months like spring and summer but need less water during fall and winter.

Some lemon trees don’t even need watering during winter as water in the atmosphere satisfies their requirements. 

Regardless of whether you have a grounded or potted lemon tree, never water without testing the soil. Place your finger at least 4 inches into the soil.

If it feels dry, water your lemon tree. However, do not water it if the soil feels moist enough. 

If you are still confused about watering lemon trees, read on about how much water lemon trees need.

#5 – Incorrect Soil

Soil forms the immediate environment around a lemon tree’s roots and lower trunk. Thus, serious discrepancies in soil ratios can affect the entire lemon tree’s wellbeing. 

One particular example is soil with excessively high levels of salts. Out of the possible side effects, falling off of leaves is the most alarming one.

Another sign of poor soil is soil that doesn’t drain fast enough! 

Poor draining soil spells disaster and needs correcting immediately. However, the catch is you can’t fix soil overnight! It takes weeks. 

The solution to Leaves falling Off Due to Incorrect Soil 

Check and adjust your soil prior to planting your lemon tree in it. Conditions to keep note of are:

  • Drainage
  • Fertility
  • pH
  • Presence of pathogens

Lemons prefer acidic well-draining soil which is highly fertile. If your garden’s soil lacks these features, use a pre-made potting mix available in stores and or online. 

#6 – Lack of Sunlight

Lemon trees need a minimum of 6 hours of sunlight while 8+ hours are the optimal amount of sunlight they need.

Sunlight is an important condition required during photosynthesis. This process is necessary as the product is energy. 

Any amount of sunlight that is less than six hours or a sharp change in sunlight patterns could initiate the loss of leaves from a lemon tree.

Correcting it will stop the ill effect. But failing to do so will only accelerate the rate of leaf loss. 

The solution to Leaves falling Off Due to Lack of Sunlight

You can provide more sunlight to your lemon tree by observing which location receives the best sun-to-shade patterns. Also, planting lemon trees in pots allows you to move them conveniently to follow the sun. 

In winter, potted lemon trees kept indoors can receive their fair share of sunlight with the help of an artificial source.

Using a LED grow light, you can ensure your lemon trees get enough light to carry out photosynthesis. 

#7 – Poor Genetic Combination 

Loss and discoloration of lemon tree leaves could also be a result of poor genetics. Cross-breeding could yield poor results that shouldn’t be used commercially. 

Also, when buying a lemon tree from a nursery, it is worthwhile to know which lemon variant the scion and rootstock are from. 

Conclusion 

Leaves are a staple identifying feature of all trees. Lemon trees are famous for their year-round evergreen status. Hence, lemon tree leaves falling off in any season is a worrying situation.

Finding the reason will be the first step to stopping the falling of lemon tree leaves. Reasons for loss of leaves in lemon trees are:

  1. Cold
  2. Disease
  3. Nutrient Deficiencies
  4. Overwatering
  5. Incorrect Soil
  6. Lack of Sunlight
  7. Poor Genetic Combination

After finding the cause, it is possible to find the solution. If left too long, excessive lemon leaf loss cannot be reversed and it could lead to the downfall of your lemon tree. 

FAQs

Why is my lemon tree dropping green leaves?

Lemon trees drop green leaves when under stress. This stress could be due to a range of factors. It could be lack/excess of a resource (water, sunlight, nutrients) or it could be disease or incorrect soil that is causing such a condition. 

How to revive a lemon tree without leaves?  

All you can do is provide the best care and conditions to your lemon tree. If it is lacking sun or nutrients, provide them. But, if it’s the soil you must switch it out without causing too much stress to the tree.