Why Citrus Trees Drop Leaves in Winter (and How to Fix It)

One of the most common questions we hear from citrus tree owners is, “Why are my citrus trees dropping their leaves in the winter?” If you’ve brought your tree indoors for the colder months, you may notice yellowing leaves followed by leaf drop. While it can be concerning, this is actually a natural process influenced by changes in humidity, temperature, and the tree’s semi-dormant cycle.

Citrus trees are semi-tropical and thrive in warm, humid environments. In the greenhouse or outdoors, relative humidity often stays around 40–65%, which citrus loves. Indoors, however, household humidity can drop as low as 18–22%. This dramatic change stresses the tree, causing it to “complain” by shedding leaves. On top of that, during winter, citrus trees enter a semi-dormant phase, pulling nutrients and carbohydrates from the leaves into the trunk and roots for storage. Once those nutrients are gone, the leaves naturally drop since they’re no longer useful to the plant.

It’s important to understand that fertilizing won’t turn yellow winter leaves green again. When leaves age and the tree has already removed the chlorophyll, they will fall off regardless of added nutrients. In spring, however, fresh growth will emerge strong and healthy if the tree has been properly cared for. During winter, your job is to maintain the right conditions so the tree survives comfortably until the growing season returns.

To reduce leaf drop indoors, try creating a more humid environment. Some growers build a simple plastic dome or tent around their tree with a small pan of water inside to increase humidity. Keep the soil lightly moist but avoid overwatering—since trees use far less water in winter, too much can lead to root rot. Bright, indirect sunlight is ideal, and a steady, balanced fertilizer will keep the tree nourished and ready to thrive once warm weather returns. (Internal link suggestion: link the phrase “balanced fertilizer” to your fertilizer product page.)

Finally, keep an eye out for pests. Spider mites, mealybugs, and scale insects often become problems once a citrus tree is moved indoors. Spider mites in particular thrive in dry air and can quickly multiply. Inspect the underside of leaves and branches regularly, and if needed, treat your tree before bringing it inside for the season. Insecticidal soaps can help with softer pests like aphids, but tougher pests may require stronger treatments. Staying proactive will save you headaches later. (Internal link suggestion: link “spider mites, mealybugs, and scale insects” to your pest control page or blog if you have one.)

At the end of the day, some leaf drop is perfectly normal in winter. By managing humidity, avoiding overwatering, and monitoring for pests, you can keep your citrus trees healthy through the colder months and ensure they burst back to life with new growth in the spring. If you’re ready to grow your own citrus tree, check out our collection of citrus trees for sale.