Yellow lemon tree foliage can be scary for a farmer. However, lemon tree leaves are not always going to be green and that is normal.
When lemon trees are young, their leaves might appear reddish and not green, but that is a common phenomenon and should not be confused with leaves’ yellowing.
In the reddening of lemon tree foliage scenario, leaves turn green as they mature. Still, in the latter, yellow lemon tree foliage leaves is often followed by the leaf drop.
Yellow lemon foliage is unnatural, and gardeners should enter panic mode at their lemon tree leaves’ yellowing.
Not only is yellow lemon tree foliage unsightly on an evergreen tree like the lemon, but it can also signal serious danger to the plant.
Yellow lemon tree foliage
The most common cause of yellow foliage on a lemon tree is a nutritional deficiency. That could be caused by a parasite that is feeding off the tree or diseased root system, but most commonly, it could be that the soil lacks nutrients.
Even though yellow leaves herald bad news for your lemon tree, it is not a death sentence because if you pay attention to your plant, it will bounce back. Don’t despair if you see yellow leaves on a lemon tree.
Causes of yellow leaves on the lemon tree
The major causes of yellow leaves on a lemon tree are discussed below.
1. Nutritional deficiencies
Lemons are heavy feeders and will deplete the soil they are growing in. When a lemon is nutrient deficiency and does not get enough nutrients, the tree leaves will become pale or yellow.
Yellow leaves indicate deficiencies in iron, zinc, nitrogen, or magnesium. Test the soil in the root zone of your lemon tree, then make the necessary adjustments. Sometimes a plant spike made for citrus trees is all you need. You can deduce the element the lemons need depending on the yellowing nature.
- Yellow all over could be a magnesium deficiency.
- Yellow midrib and veins
- Pale yellow new leaves with green veins could be due to an iron deficiency. This is also called chlorosis.
- Pale yellowing of old leaves is a nitrogen deficiency.
- Yellowing of new leaf tips and leaves with vein chlorosis could indicate a zinc deficiency.
- Interveinal chlorosis/yellowing could be a manganese deficiency
2. Winter shedding for lemons grafted on deciduous rootstock
Sometimes, a grafted lemon tree’s leaves will turn yellow if it was grafted on deciduous rootstock in winter. Many modern lemons are grafted. While grafting confers some positive characteristics like hardiness but also confers the negative traits of the rootstock.
Lemons today are often grafted onto deciduous rootstocks. This has improved the lemons’ growth area and hardiness. It also means that the lemons are forced by their hosts to hibernate through the winter even though lemons are evergreen plants.
When the rootstock initiates hibernating towards winter, the rootstock reduces the flow of nutrients to the leaves, causing them to yellow and fall. This shouldn’t worry you if it’s your case, and your lemon tree should revive in spring.
3. Seasonal changes in summer and winter
Lemon trees are sensitive to temperature changes. During summer, it is not uncommon for lemon leaves to be scorched and sunburned. Sunburnt leaves have browned apexes margins and could have spots and patches of yellow all over the leaf.
In winter, due to frostbite, exposed leaves will be yellow to brown colored. Unlike in summer, where the leaves have yellow spots and patches, frostbite discolors the lemon leaves’ entire lamina.
In both summer and winter damage cases, the leaves will fall off shortly after they turn yellow. A gardener cannot do anything to revive the leaves.
4. Overwatering
Overwatering a lemon tree causes lemon roots to rot. When the root system is impaired, the plant’s ability to absorb nutrients will also be impaired. As mentioned above, malnutrition is the leading cause of the yellowing of leaves.
Unless a plant is adopted to boggy environments, overwatering will damage the plant. Lemon and other citrus trees are not adapted for waterlogged soil growth. Overwatering a lemon tree causes the roots of the lemon to rot.
5. Pests and diseases
Sometimes the soil nutrients are sufficient but unobtainable to the plants due to pests and disease infestation. Sap-sucking insects are the primary culprits because they ‘steal’ the plant’s nutrients.
When there aren’t enough nutrients available to the lemon, the lemon leaves may develop yellow spots that eventually grow together to form large yellow patches. Aphids, whiteflies, scale insects, mites, and mealybug are the most common pests that can cause yellow leaves.
Citrus canker, greasy citrus spot, viral and microfungal infections, and diseases also cause leaves to appear yellow.
6. The lemon tree roots have outgrown the growing pot.
This applies to lemons growing in pots with a limited supply of nutrients. After 2-3 years of growing in the same soil, the lemon tree will use up all the soil available in the pot.
When the potting soil Is used up, the plant nutrition base will reduce, and so will the plant’s nutrients. The lemon tree will suffer a mild form of malnutrition, which will result in the yellow coloration of the leaves.
You therefore need to repot to treat a yellow lemon tree foliage due to the plant outgrowing the growing pot.
Why are the leaves on my Meyer lemon tree turning yellow?
Meyer lemon leaves can turn yellow for many reasons. Just like other lemon varieties, Meyer lemon leaves turn yellow for the same reasons as elaborated above.
- Nutritional deficiencies
- Overwatering
- Winter shedding for grafted trees
- Frostbite and sunburn
- Pests and diseases
Lemon tree yellow leaves nitrogen deficiency.
Nitrogen deficiency is undeniably the leading malnutrition cause of yellow leaves on lemon trees. Nitrogen is crucial ingredient information of chlorophyll, the green pigment in leaves.
A lack of nitrogen will result in the decline of chlorophyll, which will result in a less green paler green color and, eventually, yellow leaves.
How to treat yellow leaves on the lemon tree
1. Weed
Lemon trees are greedy feeders and do not like to share their growing soil with weeds. Weeds are hardy, and fast-growing plants will outcompete the lemons for nutrients. You can ensure that your lemon survives by uprooting the weeds around the trunk periodically.
2. Control pests and diseases
Pests, especially sap-feeders, can reduce the nutrients available for the lemon. Some citrus diseases can also express themselves as yellow in the leaves.
The disease can be best controlled;
- Covering pruning wounds, which are the main entry point of pathogens
- It is important to prune off deadwood because it is an incubation point for pathogens. You can use antiseptic, antifungal, antiviral, and antibacterial mixes.
Pests can be controlled by;
- Aphids and whiteflies can easily be sprayed off with regular garden hose blasts
- Scale and mealybugs (which often have waxy coatings) may need chemical treatment or horticultural oil, depending on the season.
- Mites, which are technically arachnids and not insects, are quickly dispatched with a soap-based miticide.
- Insecticidal soap can fight off an array of insect pests.
3. Fertilize
As mentioned above, malnutrition causes yellow leaves due to a lack of nutrients. You can prevent yellowing by frequently fertilizing with fertilizer enriched with the major NPK and the micronutrients.
4. Water efficiently
A gardener must water just enough for the tree water to avoid under and overwatering. Watering once to twice a week should suffice on average.
5. Control temperature
Lemons are sensitive to temperature and environmental changes. It is essential to insulate the tree in winter or potted to transfer it indoors to protect the tree from yellowing due to frostbite.
In summer, too much sunshine can burn and scorch the tree leaves, so a farmer can put screens above the tree to protect the lemon from the afternoon scorching sun.
Lemon tree yellow leaves Epsom salts.
Magnesium deficiency results in lemon leaves that are yellow all over. The plant has yellow leaves due to a lack of magnesium. That could be because there isn’t much in the soil or because the soil is too alkaline. In alkaline soils, magnesium ions precipitate and cannot be absorbed by the plant.
If the magnesium deficiency is due to alkaline soils, adding gypsum or other acidic rock minerals will fix it. Otherwise, add Epsom salts.
Epsom salts are rich in magnesium. Magnesium deficiency is one of the causes of yellowing of leaves, as elaborated above. Epsom being rich in magnesium is the perfect antidote for leaf yellowing induced by magnesium deficiency. Magnesium deficiency is common in older trees.
How to make an Epsom salt fertilizer:
1. Mix 20g of Epsom salts in a liter of water.
2. Depending on the tree’s height, determine the doze, 20g of Epsom salt per 1 meter of tree height. If your tree is 6 meters high, the doze for that tree will be 120g of Epsom salt in 6 liters of water.
3. After mixing the fertilizer, spray on the soil and follow with generous watering.
Yellow spots on lemon leaves
A lemon plant can have yellow spots for many reasons.
- Sunburn can cause yellow spots on leaves
- Diseases like citrus canker
- Pests like scales and aphids can also cause leaves to have yellowish-brown spots on the leaves.
Yellow leaves on lemon tree Australia
Australian soils are often deficient in iron. The yellowing of leaves often observed in Australia is chlorosis. The veins are dark green but everywhere else on the leaf is yellow.
Farmers can remedy this by adding iron-enriched fertilizers to their soils.
FAQs
You can fix yellow leaves on a lemon tree by watering adequately, fertilizing, and controlling pests and diseases.
Unless your lemon tree is affected by citrus greening, which is incurable, the lemon tree should bounce back with extra care and attention from the farmer.
One common symptom of over-watering is yellow leaves. Suppose your lemon tree has yellow leaves and no pests or diseases for lack of nutrients causing the yellowing. In that case, it’s most likely because you overwatered.
Many lemon varieties turn yellow when they ripen. It is not uncommon for lemon fruits to turn yellow as they ripen.
Conclusion
Having yellow lemon tree foliage on your lemon tree can be scary for any farmer. Don’t worry!
Use the tips and hacks above and you will be able to control and even prevent yellow lemon tree foliage.