Calamondin leaves turn yellow when there is an environmental factor causing plant stress. As a plant owner, you need to be able to identify the warning signs of potentially damaging conditions that may harm your plant. Narrowing down the cause of the yellowing is the first step in fixing the problem.
The most common causes of yellowing calamondin leaves are overwatering, aging, lack of nutrients, pests and toxicity.
In this article, we will discuss the different causes of yellowing calamondin leaves and how to remedy each one.
Why are my calamondin leaves turning yellow?
Overwatering
The most common cause of yellowing calamondin leaves is overwatering. When the plant’s roots are constantly in soggy soil, they will drown and die. The dead roots will start to rot and become susceptible to diseases and pests. The rot will travel up the root, into the stem and eventually affect the leaves, hence the change in color.
When the roots of the plant are compromised, the plant is no longer able to effectively absorb nutrients, leading to a downward spiral of its general health.
A calamondin plant can be overwatered by watering it too frequently, planting it in soil that is compacted or retains moisture too well, or using a pot that does not have drainage holes at the bottom. All three of these factors, when present together, cause the plant to stand in boggy soil for longer than it should.
You can check if the plant is overwatered by digging it up and inspecting its roots. If there are portions of the roots that have turned brown or black, then the plant has root rot. You can cut off these rotten roots with sterile scissors. After removing all the damaged roots, let the remaining roots air dry. Dispose of the old soil properly and clean and sterilize the pot before repotting the plant. Use new, well-draining soil and ensure that there are drainage holes in the pot.
Establishing a watering schedule suitable for your plant is also very important. The best way to know when to water your plant is to check the top few inches of the soil in the pot. If the soil is dry, you can water the plant, but if it is still moist, wait one or two days and check the soil again.
Aging
Not all of the causes of yellowing calamondin leaves are negative. Just like any plant, older calamondin leaves turn yellow and then brown before they fall off the plant. This is just part of the plant’s natural life cycle and should be no cause for concern. Leaves die and fall off because the plant focuses its resources and energy on new growth, so it will cut off the old leaves causing them to dry out and fall off.
There is really nothing that needs to be done if your calamondin plant is healthy overall, but if it bothers you to look at the yellow or brown leaves, you can always just remove them when you prune the plant.
Lack of nutrients
A calamondin plant that is lacking in iron, zinc, nitrogen or magnesium can suffer from yellowing leaves. Calamondin plants are part of the citrus family and require these nutrients in order to yield fruit.
A plant with a nitrogen deficiency will have yellow-green leaves, while a plant that has yellow-green blotches at the base of the leaf has a magnesium deficiency. A plant with a zinc or iron deficiency will have yellow leaves with green veins.
You can correct these deficiencies by feeding the plant with a fertilizer that contains these nutrients.
Pests
The calamondin plant attracts insects that feed on its sap, including whiteflies, aphids and spider mites. These insects destroy the leaves when they feed on them, leaving yellow spots that coalesce to form bigger blotches. The more the leaf is fed on, the faster it turns yellow, then brown, and eventually falls off.
Suspect spider mites if you see webs on the leaves.
You can remove these insects by blasting them off with the spray nozzle on your hose. You can also use insecticidal soap or neem oil. Treat the plant once a week for a month to ensure that all the insects have been killed.
Toxicity
If a calamondin plant is grown in soil with high levels of a certain mineral, this can affect the plant’s growth, including the color of its leaves.
Calamondin trees grown near the ocean will have a hard time dealing with the high salt content of the soil. The leaves will turn yellow or brown and fall off the plant.
Chlorine toxicity can also stunt the plant’s growth, while boron toxicity causes premature leaf drop and spotting on the underside of the leaves.
Tips on growing a calamondin plant
Feed the plant
As mentioned above, calamondin plants require nutrients to produce fruit, so you should make sure these nutrients never get depleted. Apply fertilizer every few months so that the plant remains healthy and yields fruit.
Good drainage
In order to avoid overwatering your calamondin plant, make sure you use soil that is well-draining and not compacted. Use a pot or container that has drainage holes at the bottom, so that if you accidentally overwater the plant, the excess water will simply flow out of these holes. Choose a clay or terracotta pot, because these materials are more breathable and allow water to escape better than plastic or steel pots.
Watering techniques
A new plant owner can be a little too enthusiastic when caring for their plant. Remember that calamondin plants only need to be watered once a week, and any more than that can lead to root rot. In warmer months, you may need to reduce the number of days between watering, while watering in the cooler months should be less frequent.
Conclusion
A calamondin plant that has yellow leaves is experiencing stress from an environmental factor. The key to fixing the problem is to correctly identify the cause of the stress.
The most common causes of yellowing calamondin leaves are overwatering, aging, lack of nutrients, pests and toxicity.
Calamondin plants are relatively easy plants to grow and do not require much attention, so as long as you provide them with all of their living requirements, you should have no problem growing them.
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