Skip to Content

6 Reasons Your Lemon Tree Leaves Are Turning Yellow

Having a lemon tree at home and enjoying its fresh fruit is a dream for many. But remember, growing a lemon tree requires some know-how, as they can be a bit tricky to care for.

Lemon trees love lots of light. Ideally, they should get around 12 hours of direct sunlight daily, but they can manage with a minimum of 8 hours. If they don’t get enough light, you might notice the leaves turning yellow and falling off. The best spot for your lemon tree indoors is near a big window that faces south or west, where it won’t be blocked from the sun. If it seems like your tree isn’t getting enough light, think about getting a grow-light.

Now, let’s dive into the various reasons why your lemon tree’s leaves might be turning yellow.

1. Nutrient Deficiency

Lemon tree leaves turning yellow because of chlorosis.

Lemon tree leaves turning yellow because of chlorosis.

Usually, if a lemon tree’s leaves are turning yellow, it’s because the soil doesn’t have enough nutrients. Lemon trees need a lot of nitrogen because they have big fruits and leaves.

Many people grow lemon trees in pots, and sometimes the soil in these containers doesn’t have enough nutrients for the tree to thrive. The tree then uses nitrogen from older leaves to grow new ones, causing the older leaves to turn yellow while the veins stay green. This condition is known as chlorosis.

Chlorosis might also happen if there’s not enough magnesium, zinc, or iron in the soil.

Here’s How to Fix It:

  1. Test the Soil pH. Lemon trees prefer a soil pH around 6.5. If your soil’s pH is above 7.0, use an acidifier to lower it to about 6.5.
  2. Apply a fertilizer specially made for citrus trees. It should have plenty of nitrogen and also contain iron, magnesium, and zinc.
  3. Fertilize your lemon tree 2-3 times a year, starting from the end of February. Do the second round of fertilization after the tree has flowered. Avoid fertilizing in late fall or winter.

2. Temperature Changes

Lemon tree leaves turning yellow because of heat.

Lemon tree leaves turning yellow because of heat.

Another thing to watch out for is sudden changes in the growing conditions, especially changes in temperature. Lemon trees do best in temperatures between 70-80 °F. They can handle small variations, but not too much.

For instance, if you move your lemon tree outside in the spring, be careful. It could get damaged if the night temperatures drop below 50 °F. This kind of cold can shock the tree, and one sign of this is its leaves turning yellow.

Here’s How to Fix It:

  1. Avoid moving your lemon tree outdoors if the night temperatures are still chilly.
  2. Give the tree an extra watering to help it recover if it’s been exposed to colder temperatures.

3. Root Rot

Lemon tree leaves turning yellow because of overwatering.

Lemon tree leaves turning yellow because of overwatering.

Root rot in lemon trees usually happens when the soil stays too wet. This might be because you’re watering the tree too often, or the soil isn’t draining well.

When the roots rot, they can’t deliver water to the leaves properly. As a result, the leaves may turn yellow and fall off. Plus, you might notice a bad smell near the roots, indicating decay.

Here’s How to Fix It:

  1. First, cut back on watering. Don’t water your lemon tree too often.
  2. Let the soil dry out for a few days.
  3. In the future, water the tree only when the top 2-3 inches of soil feel dry (for potted trees, check the top 1-2 inches).
  4. While the tree is recovering, provide some shade to protect it from intense sun.

4. Dehydration

Underwatering

Lemon tree leaves turning yellow because of underwatering.

Not watering enough can also lead to the leaves of the lemon tree turning yellow, particularly during the hot summer months or if the tree is in a pot. The signs of underwatering look a lot like those of overwatering because, in both scenarios, the roots fail to deliver adequate water to the leaves.

Here’s How to Fix It:

  1. Give your lemon tree about 1-2 gallons of water.
  2. After that, make sure not to let the top 1-2 inches of soil in a pot, or 3 inches for garden-planted trees, completely dry out before watering again.

5. Diseases

Lemon tree leaves turning yellow because of disease.

Lemon tree leaves turning yellow because of disease.

Diseases are another common issue when growing lemon trees. They can significantly affect the plant’s health, often resulting in yellowing leaves.

These diseases are triggered by pathogens, but it’s the growing conditions that really allow these diseases to take hold. Factors like a weakened plant or poor air circulation in the area can increase the risk of disease.

Here’s How to Fix It:

  1. Start by removing any severely damaged leaves.
  2. Treat the tree with a broad-spectrum fungicide. Look for products that contain copper.
  3. Plan to reapply the treatment after some time has passed.
  4. Make sure to keep your plant in an area with good airflow and plenty of sunlight.

6. Too Much Sunlight

Too much sun

Lemon tree leaves turning yellow because of too much sun.

Not getting the right amount of sun can also lead to the leaves of a lemon tree turning yellow. Lemon trees thrive in full sunlight. However, for those growing in pots without a fully developed root system, too much sunlight can be harmful. Excessive UV light can damage the leaf cells, causing the leaves to first become pale and then turn a yellowish-green.

Moreover, if a lemon tree is quickly moved from indoors to the harsh, direct sunlight outside, its leaves might get sunburned.

Here’s How to Fix It:

  1. Temporarily move your lemon tree into a spot with partial shade.
  2. Gradually increase its exposure to sunlight to help it adjust. This approach will help you find the ideal location for your plant.
  3. Give your lemon tree a one-time application of liquid fertilizer to support its recovery.