New growth on lemon trees will start out light green. These leaves will eventually turn to a darker green color after they are exposed to sunlight. Light green leaves on lemon trees can also be caused by magnesium, nitrogen or iron deficiency. Lemon trees can recover from these problems if they are treated early before the leaves turn yellow or brown.
This article will explore all you need to know about what cause lemon trees to develop light green leaves and what to do to solve each one.
This post may contain affiliate links. If you click one of these links and make a purchase, I may earn a commission at no additional cost to you. In addition, as an Amazon Associate I earn from qualifying purchases.
Why lemon trees develop light green leaves
Here are the top causes of light green leaves on lemon trees and what to do about each one. Light green leaves can occur on a healthy tree as well as be caused by a nutrient deficiency. Check out more details below.
1. New growth
The new growth on lemon trees will look light green in color as it develops. Small leaves start off a deep brown or dark red color and then grow larger and turn light green. As the chlorophyll develops in the leaf it will become greener and darken in color.
More sunlight will cause the leaves to develop more chlorophyll and turn a darker green color. Chlorophyll is essential for leaves to turn sunlight and carbon dioxide into carbohydrates which used for plant growth.
New leaves take around 4 weeks to turn from light green to a mature leaf color that is darker green. Lemon trees can grow multiple flushes of new growth at the start of spring, summer and even at the start of fall.
2. Magnesium deficiency
Magnesium deficiency in lemon trees can cause the leaf to turn a light green or light yellow color between the veins. The veins of the leaf will stay green as well as at the base of the leaf.
Over time the leaf will turn yellow, plant growth can slow and the tree can eventually die. Magnesium is used up by the plant during normal growth and the production of fruit. It is essential to feed the tree regularly throughout the growing season to avoid magnesium deficiency and light green leaves.
To treat magnesium deficiency, add Epsom salts diluted in water.
For more on this, check out my previous article here on Epsom salts on lemon trees: How to use Epsom Salts on Lemon Trees | 5 Easy Steps
3. Nitrogen deficiency
Light green leaves on lemon trees can be caused by a nitrogen deficiency. If mature lemon tree leaves are turning light green this could be the problem. Nitrogen can be washed out of the soil if there is high rainfall or if you are adding too much water yourself.
Nitrogen is also used up in the soil over time by the lemon tree. Poor quality potting mix without added fertilizer will also quickly run out of nitrogen causing problems for your plant.
To avoid and treat nitrogen deficiency add pelleted chicken manure to your lemon trees at the start of the season. Scatter small amounts around the root zone of the tree to feed it a small amount of nitrogen over the next 3 months.
Top dress citrus in spring with a mix of aged manure and compost which will provide a gentle amount of nitrogen when the plant is watered.
For more on how to top dress citrus, check out my article here: How to top dress citrus trees | The Easy Way
4. Iron deficiency
Iron deficiency can also cause lemon tree leaves to turn light green and then yellow with deep green veins. Iron deficiency can occur over time if the tree is not fed regularly.
To treat iron deficiency give your tree a dose of iron chelates. These come in powdered or liquid form. The powder will be diluted into water and applied to the root zone of your plant. This will fix the deficiency and if caught early, the leaves will get their color back soon.
There are two main options to keep your tree happy with regular fertilizer.
1. Give your tree pelleted chicken manure at the start of every season and a dose of iron chelates and trace elements at the start of spring.
2. Feed your lemon tree at the start of every season with a specialized citrus food. This will contain all the nutrients the plant needs. You can top up with pelleted chicken manure in spring to feed the worms and soil bacteria and give your tree a nitrogen boost.
For more on fertilizing lemon trees, check out my article here.
5. Lack of sunlight
Lemon trees can develop light green leaves if the plant is lacking sunlight. Trees that are grown in deep or part shade can grow long, leggy stems and the leaves will look pale. This is because the tree needs at least 6 hours of bright sunlight to develop good amounts of chlorophyll in their leaves.
Lemon trees need a full sun position to thrive so move potted plants out to an open are where they gets as much sun as possible. Trees will grow healthier roots, darker leaves and lots of fruit if they are given the sunlight they need.
Lemon Trees with Light Green Leaves | Summary
Lemon trees will develop light green leaves if they are not getting enough sun, if the leaves are young or if they are lacking essential nutrients. The best way to prevent this happening is to plant the tree into soil improved with aged cow manure and compost, feed the plant regularly and plant it in a full sun position.
Keeping lemon trees well fed with a regular regime of fertilizer is essential. Lemon trees use up large amounts of nutrients when they are growing fruit so you will need a top up regularly. Citrus fertilizers make it easy to keep your lemon trees happy but you can also do it yourself with pelleted chicken manure, iron chelates and trace elements.
I am an accredited practicing dietitian, experienced gardener and a dedicated cook. I love writing and sharing my experience so you can learn from my successes and mistakes.