Lemon tree leaves become yellow in temperatures below 50°F and when the soil is deficient in nutrients. Underwatering and overwatering and spider mite infestations that generate microscopic pin-sized yellow spots on the leaves can turn the leaves yellow besides this.
Leaf drop is commonly connected with yellowing lemon tree leaves; however, the tree may often be rejuvenated with proper care.
In our guide, you can learn more about lemon trees, yellow leaves and what you need to do to fix the issue. By the end, you’ll have more information on the various ways you can solve your lemon tree yellow leaves problem. (Read Avocado Leaves Turning Brown)
Why Are My Lemon Tree Leaves Turning Yellow?
The position, and range of lemon tree yellow leaf foliage provide insight to why they’ve changed color.
A lemon tree can turn yellow because of extreme heat or cold, nutritional deficiencies, illnesses, or toxicity. However, these aren’t the only issues as there can be a simpler solution to make leaves turn yellow.
Typically, lemon tree leaves are reddish when they first emerge, and as they age, they turn dark green above and light green underneath.
Here’s some of the reasons you can find lemon leaves on lemon tree.
Heat and Lemon Trees
Lemon tree leaves turn yellow if exposed to too much sunlight or they face temperatures colder than they can handle.
Scorched leaves, appear bleached or have yellow patches, usually emerge primarily in sections of the tree exposed to the afternoon sun, but cold temperatures damage leaves across the tree.
Only the leaf tips or outer leaves turn yellow when the temperature drops, leaving the inside leaves green.
Lemon tree foliage turn brown and the older leaves die after prolonged exposure to cold, and growing fruit may fall. If you have scorched and cold-damaged leaves, these won’t impact the trees’ overall health, and they fall naturally. Temperatures below the hardiness limit of lemon trees prevent them from growing.
Yellow leaves on a lemon tree are signs of a nutritional deficiency. The symptoms differ depending on which nutritional deficiencies they have.
For example, nitrogen deficiency results in light green turn leaves yellow that extend throughout the tree; magnesium deficiency appears as a yellowish-green blotch at the leaf base that spreads outward, and zinc or iron deficiency results in yellow leaves with green veins.
Most nutritional shortages for yellow leaves on lemon tree can be corrected by feeding a lemon tree a citrus fertilizer, such as 10-15-15 spikes with micronutrients.
In early spring and mid-fall, drive citrus fertilizer spikes into the ground around the tree’s drip line, no closer than 2 feet from the trunk, or apply according to the manufacturer’s directions. Lemon trees are heavy feeders, and you need to fertilize to accommodate this. (Read Arizona Shade Trees That Don’t Shed)
Alternatively, if you’d instead make your own lemon tree fertilizer out of common kitchen scraps.
Nutrient Deficiency and pH Levels
To absorb nutrients from the soil properly, lemon trees require a soil pH of 6.0-7.0. Even if you use an excellent fertilizer for your lemon tree, it won’t use many of the nutrients if the soil pH isn’t correct. As a result, it may grow yellow leaves, and ultimately your citrus limon could die.
If the soil around your lemon tree is too acidic (below 6.0), for example, you can add some banana peels or wood ash (make sure the ash is not processed charcoal or coal as they can contain chemicals and toxins that can damage the tree and soil).
If your lemon tree’s soil is too alkaline (above 7.0), add some coffee grounds, peat moss, sand, or pine needles to balance it out.
Disease could be visible on yellow lemon tree leaves. A lemon tree growing in poorly drained soil may develop Phytophthora root rot, which causes pale green to yellowish leaves.
Citrus greening, which is characterized by yellow leaves on only one side of the tree and uneven yellowing of individual leaves, is another disease that can affect lemon trees.
Citrus greening causes stunted growth, leaf and fruit loss, asymmetrical fruit, and twig dieback, and is carried by psyllids (aphid-like insects). In some areas, citrus greening on citrus trees is required to be reported to agriculture officials.
Yellow lemon tree leaves develop patterned fading when grown in soil containing highly harmful chemicals. Lemon trees don’t like soils with excess salts.
The tree shows signs of yellow foliage, golden, or they turn brown from the tip to the stem and drop early in the year.
Stunted growth is another sign of sodium or chlorine toxicity. Boron toxicity causes mottled or lemon tree leaves turn yellow with spots on the undersides and early leaf drop. Twigs can also die back in severe circumstances.
How Can You Tell If a Lemon Tree Is Overwatered?
Over-watering is the most prevalent cause of yellowing lemon tree leaves. While lemon trees are hardy, they are picky about their soil and watering.
Lemon trees grow best in loose, well-draining soil watered once or twice a week. Lemon trees are used to higher and longer rainfalls because they are subtropical plants. As a result, they favor deep watering sessions over shallow.
The tree will establish deeper roots and access deeper water tables because of this.
Unfortunately, this can cause the roots to sink, resulting in a range of problems, which are the most prevalent of which are yellow leaves. (Read Why Are My Pumpkins Leaves Turning Yellow)
Deep watering means carefully soaking the dry soil, so the water sinks deeper into the ground. The tree’s roots have little motivation to develop deeper with shallow watering as this just wets the top 2-4 inches of soil. With this, you get issues like poor anchorage and a greater reliance on more frequent waterings in full sun.
- Deep watering encourages the tree to establish deeper roots that can access all water among other benefits:
- When the lemon tree’s roots develop deeper, you’ll be able to access deeper water tables, which means you’ll be able to water it less frequently, and sometimes, you won’t have to water your plant, even when in full sun of summer.
- The roots help retain more water in the soil, which benefits the lemon tree and the lemon tree and adjacent plants. Because water evaporation is minimized, the soil can give a more consistent supply of water to nearby plants.
- Beneficial bacteria and earthworms are among the life that nourishes the lemon tree.
- Over-watering the lemon tree might cause yellow leaves caused by too much moisture, stagnant water, and fungus such as root rot.
- When you water lemon trees, the ideal rule is to only water when the top 2-4 inches of soil are dry. Watering 1-2 times a week is typical; however, it depends on the size, soil, and weather of the tree.
- To test the moisture in the soil, you can either stick your finger in it or use a moisture meter.
- Ensure you don’t let the plant-soil dry, if under-watered its leaves may dry, brown, and fall off.
Overwatering your lemon tree or inadequate soil drainage cause root rot, as previously stated. When water sits stagnant for long periods, it rots, and a fungus is known as root rot (or Phytophthora) emerges. Lemon tree leaves may turn yellow and fall off because of this.
Stop watering the tree and allow the soil to dry out to fix root rot. The fungus will die as the soil dries out.
However, it would help if you struck a balance because you do not want your lemon tree to perish. Monitor the soil and the tree’s health to see if this is working.
If this doesn’t work, you may need to adjust the soil around the lemon tree. This entails softly stirring in sand for proper drainage to get rid of excess water. Simply repotting potted trees with fresh soil can help solve the problem.
If you have a lemon tree that you want to change the soil around the root system, be careful not to dig too deep or too close to the tree trunk because some of the tree’s shallow roots may be harmed.
Whiteflies may be present if your lemon tree has mottled or yellow leaves.
Whiteflies are little white insects related to aphids and congregate beneath leaves and feed on them, leaving a sticky honeydew behind.
If the number of whiteflies grows too great, the tree’s ability to photosynthesize and obtain energy for the plant is harmed and falling leaves as they dry, turn yellow and fall off.
Aphids are fairly frequent in most gardens, and they drain nutrients from the leaves, similar to whiteflies, and damage the tree, causing leaves yellow and fall off.
If your lemon tree’s leaves are curled, yellowing, or damaged, look under them for clusters of white, black, or yellow dots.
Aphids, like whiteflies, are commonly discouraged and destroyed using a burst of pressured water or a soapy spray. Neem oil or ladybugs are two other options for aphid management. Soapy water can solve get rid of both pests and stop your leaf yellowing.
Symptoms vary, yet you can use these methods of pest control on house plants as well, to fix yellow leaves.
Spider mites are the third pest causing yellowing in leaves. The mites feed on the tree’s sap, causing the leaves to become dull, then yellow, before turning brown and falling off.
If spider mites have infected the plant, just use a strong stream of water to hose off the bugs or use the other methods you see here.
Other Reasons for Yellow Foliage
Leaves are built for photosynthesis, not for absorbing nutrients that come into touch with them, therefore they don’t fertilize them. Roots are experts in obtaining nutrients from the soil. So, instead of nourishing the leaves, concentrate on the soil.
Mulch the base of lemon trees to help keep water in the soil, offer a steady flow of nutrients, and keep the sun from drying up the soil. Pine needles, leaves, and grass clippings are among the best mulches for citrus trees. (Learn How To Tell If Yellow Squash Is Bad)
Once or twice a year, provide 1-2 inches but avoid mulch around the base of the tree trunk as this can lead to mold forming.
Providing 1-2 inches of compost, like mulching, can be an excellent complement for lemon trees, and in certain situations, can replace fertilizer. Apply the compost only once at the start of the growing season and avoid allowing it to come into direct contact with the trunk.
Pruning lemon trees is an excellent idea since it trains the tree to focus on a specific type of growth. Young lemon trees, for example, should have their blossoms and fruit plucked or pruned so that the tree can refocus its energy and mature quicker.
Excess branches and foliage on mature lemon trees can be cut to allow more new growth in blossom and fruit production in areas where less light gets to the tree.