Why Your Lemon Tree Leaves Are Turning Yellow (2024)

By Kaitlyn Bain

Published Dec 15, 2023

If the leaves of your lemon tree are turning yellow it could be a warning of another problem. Discover the top reason lemon tree leaves turn yellow.

Why Your Lemon Tree Leaves Are Turning Yellow (1)

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Key Takeaways

Yellow leaves on a lemon tree can be caused by overwatering or underwatering. Maintaining a proper watering schedule and ensuring good drainage is important.
Nitrogen deficiency can cause yellow leaves in lemon trees. Fertilize regularly with a high-nitrogen citrus fertilizer to prevent this.
Iron, zinc, and manganese deficiencies can also result in yellow leaves. Avoid overwatering, maintain adequate nitrogen levels, and adjust soil pH to prevent these deficiencies.

Nothing beats the citrusy smell of a lemon tree throughout the year. The bright green leaves and sunny yellow fruit brighten up any room they're planted in. However, sometimes the green leaves of your lemon tree can turn yellow. When you see meyer lemon tree leaves turning yellow, it's a sign that something in your plant's environment is wrong and needs to be adjusted.

Discover the top reasons why your lemon tree leaves are turning yellow, so you can correct the problem and bring your tropical citrus tree back into peak health!

1 The Soil Has The Wrong Amount of Water

Both overwatering and underwatering can cause yellow leaves

Why Your Lemon Tree Leaves Are Turning Yellow (2)

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When the soil of your lemon tree becomes too wet it makes it difficult for your plant to absorb nutrients. The water dilutes the nutrients available in the soil and makes it difficult for your lemon tree to suck them up. This causes a yellowing in the leaves which will eventually fall off the plant.

There are a variety of reasons that the soil can become oversaturated with water, including overwatering, heavy clay soils, and a lack of proper drainage in the soil or your pot. Watering your meyer lemon tree is all about moderation. You don't want too much, but you also don't want too little.

When the soil is excessively dry, the plant isn't getting enough water or nutrients and the leaves will turn yellow before shriveling up and dying. To avoid these issues, it's best to follow a proper watering schedule and ensure that any excess water can drain away from the plant. You should also choose your soil with care.

When to Water	Water lemon trees when the top 2 to 3 inches of soil is dry. Use your finger or a water meter to see if the soil is still wet. Container planted lemon trees should need water once every week or two.
How Much Water	Water deeply and thoroughly until water runs out the drainage holes of the pot. On average, lemon trees need an inch or two of water a week, or 4 to 6 inches of water a month.
Improving Drainage	Make sure your pot has drainage holes drilled in the bottom with a tray to collect water underneath. After watering your lemon tree, remove any water in the drainage tray to prevent the roots from sitting in water. Choosing a balanced potting soil that doesn't retain too much water is important in improving soil drainage.
Best Soil For Lemon Trees	If your soil is waterlogged, remove it and replace it with new potting soil. The ideal soil for citrus trees is an equal mix of potting soil, organic matter, and either vermiculite or perlite.

2 Your Tree Has a Nitrogen Deficiency

Nitrogen deficiencies lead to older leaves yellowing

Why Your Lemon Tree Leaves Are Turning Yellow (3)

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Nitrogen is one of the most common nutrient deficiencies in lemon trees. If you're wondering, 'why are my lemon tree leaves turning yellow,' it's possible low nitrogen might be the culprit.

Nitrogen deficiency — new leaves are green and healthy, old leaves are yellow and fall off.

Nitrogen is what's known as a mobile nutrient. According to the UC Master Gardener Program of Alameda County, when a lemon tree doesn't have enough nitrogen in the soil it can move it where it needs it the most. This is why a nitrogen deficiency in the soil of lemon trees leads to yellowing of the older leaves. The lemon tree uses the nitrogen on the younger leaves in order to keep them healthy.

Proper fertilization is vital for lemon trees, especially indoor meyer lemons, since they're heavy feeders and can deplete the limited nutrients in potted soil quickly.

When to Fertilize	Fertilize lemon trees three times a year. The first fertilization should occur in February. Add two additional fertilizer rounds spaced four to six weeks apart.
What Type of Fertilizer to Use	A high-nitrogen citrus fertilizer. Look for a fertilizer with twice the amount of nitrogen as it has phosphorus and potassium. This should be a NPK ratio of 2:1:1
Adding Nitrogen to a Plant With Yellow Leaves	If the lemon leaves are already turning yellow, you can use a foliar spray to add nitrogen to the leaves. Urea is a good source of nitrogen that can be used as a foliar spray. Mixing compost or well-rotted manure into the soil is another good way to boost nitrogen levels.

3 Iron, Zinc, and Manganese Deficiencies

A lack of these minor nutrients can cause yellow leaves

Why Your Lemon Tree Leaves Are Turning Yellow (4)

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Iron, zinc, and manganese aren't mobile nutrients, so any deficiency will appear in new growth as new leaves are forming. Although lemon trees don't need a lot of these nutrients, a lack of iron, manganese, or zinc can turn the leaves yellow. Often, the problem isn't with how much of these nutrients are in the soil. Instead, the problem lies with the plant's ability to absorb them.

Lack of iron — leaves are yellow while the veins in the leaves are green.
Lack of zinc — the terminal leaves at the end of a branch turn a mottled yellow color. This yellowing appears in between the major veins of the leaf while the veins themselves stay green.
Lack of manganese — the veins of young leaves turn a pale, light green.

There are a few things that can cause deficiencies of these minor nutrients in lemon trees including overwatering, a lack of nitrogen, and a high soil pH.

Overwatering	Follow a regular watering schedule. Only water lemon trees when the top 2 to 3 inches of soil are dry.
Low Nitrogen Levels	Add nitrogen to the soil by fertilizing three times a year.
High Soil pH	Lemon trees need a soil pH of 5.5 to 6.5 When the pH level rises to 7 it makes it difficult for your lemon tree to absorb nutrients in the soil. Lower soil pH by adding elemental sulfur to the soil of your lemon tree.
Adding Iron, Zinc, or Manganese to Lemon Trees	Foliar sprays are the best way to add these nutrients to a lemon tree that already has yellowing leaves.

4 The Roots of Your Tree are Damaged

Damaged roots can't absorb nutrients

Why Your Lemon Tree Leaves Are Turning Yellow (5)

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The roots of your lemon tree are vital to the health of your plant. If you have healthy roots, your lemon tree is more likely to be healthy. If the roots become damaged or rotten, your lemon tree will struggle to absorb enough water and nutrients to keep it healthy. This can lead to a yellowing of the leaves which will eventually fall off. If left long enough, root rot can end up killing off your entire lemon tree.

Damaged roots — leaves turn yellow, then fall off the lemon tree.

Inspect The Roots	Carefully remove your lemon tree from it's existing pot and brush off as much soil as possible. Look for roots that are mushy, smelly, and yellow or brown in color — these signs of root rot. Healthy roots should be firm and white.
Prune Damaged Roots	Sterilize and sharpen a pair of garden pruners. Cut away any damaged or rotten roots. Remove the old soil and prepare a pot with fresh, clean soil.
Use Hydrogen Peroxide	Prepare a solution of 3 percent hydrogen peroxide and water in a 1:4 ratio. Drench the new soil with the hydrogen peroxide solution. This solution of hydrogen peroxide will kill any fungus that may remain on your lemon tree's roots.
Repot Your Lemon Tree	Carefully plant your lemon tree in the center of its new pot. If you're repotting because of root rot the pot can be the same size as the previous pot.
Prevent Root Rot	Make sure your lemon tree is in a pot with enough drainage holes. Never allow your lemon tree to sit in water. Only water once every week or two when the soil is dry 2 to 3 inches below the surface.

5 Not Enough Sunlight

Low light can cause yellow leaves

Why Your Lemon Tree Leaves Are Turning Yellow (6)

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Lemon trees thrive in full sun. If they don't have enough sunlight, it can cause the leaves of your lemon tree to turn yellow before eventually falling from the plant.

Lack of sunlight — the leaves turn yellow and fall from the branches.

If your tree is planted outdoors, the original planting location will determine how much sunlight your lemon tree receives. However, if you're growing a meyer lemon tree indoors, you're in control of the amount of sunlight your lemon tree gets. In addition to yellowing leaves, a lack of sunlight can prevent blooms from forming. Without blooms, you won't get any fruit on your lemon tree.

Hours of Sunlight for a Lemon Tree	Lemon trees require full sun. In order for your lemon tree to thrive, provide it with eight to 12 hours of direct sunlight daily.
Increasing Sunlight of Outdoor Trees	Choose a sunny location prior to planting — the south side of your home and yard has the most direct sunlight. Prune overgrown branches or foliage to allow more light into the center of the lemon tree.
Increasing Sunlight of Indoor Trees	Keep your lemon tree in front of a sunny window. South-facing windows will provide your lemon tree with the most sunlight.

6 The Temperature is Too Cold

Keep temperatures above 40 degrees Fahrenheit

Why Your Lemon Tree Leaves Are Turning Yellow (7)

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Lemon trees love warm temperatures because they're native to tropical and subtropical regions of the world. If the temperature drops too far, you may see a yellowing of the leaves.

Cold temperatures — leaves turn yellow and may curl up before dropping off.

Cold soil makes it difficult for the nutrients in the soil to reach the plant, which often leads to nutrient deficiencies. Extreme cold can also damage the leaves directly, especially if there's been a frost. Older, mature lemon trees will handle a bit of a cold snap better than newly planted young trees.

The temperature your lemon tree thrives at will change based on whether it's in a fruiting period. If the temperatures in your area drop below 40 degrees Fahrenheit in the winter time, you'll need to move your lemon tree indoors to provide it with a warmer environment.

Ideal Temperature For Lemon Trees	Lemon trees prefer an environment that's between 50 and 80 degrees Fahrenheit. Once the temperature drops below 40 degrees Fahrenheit, it's time to move your lemon tree indoors or to a sheltered location.
Temperature For Fruiting Lemon Trees	If your lemon tree is fruiting, keep daytime temperatures between 65 and 75 degrees with nighttime temperatures around 55 degrees Fahrenheit. The colder night temperatures signal to your tree that it's time to ramp up bloom production.
Protecting Outdoor Trees From Cold	Use a thick layer of mulch around the base of the tree to prevent the roots from freezing. Cover the top of the lemon tree with a frost barrier or cloth to prevent damage if there's an unexpected frost.

Lemon trees are a delicious source of citrus fruits throughout the year. They look amazing whether they're covered in white blooms, yellow fruit, or just their shiny green leaves. In order to keep your lemon tree healthy, it's important to know why the leaves of your lemon tree might be turning yellow. With a few tweaks to your care routine, you'll have your lemon tree happy and healthy in no time!

Be sure to share this article with any friends or family that own a lemon tree, so they can troubleshoot lemon tree yellow leaves as well!