What to Do When a Lemon Tree Loses Leaves in Winter

Lemon Tree

Is your lemon tree suddenly starting to lose its leaves? There are a few common causes that make citrus plants like lemon trees lose its leaves. This may include pest infestations, plant diseases, nutritional deficiencies, and weather-related damages. In this case, it most likely has something to do with the incoming cold winter weather.

The Damage from Cold Weather

Lemon trees in general do not like cold temperatures (which is why a lot of lemon and lime exports come from warm-weather countries). You may expect the leaves to start dropping once the average temperature outside starts to drop to 28F or lower.

For young lemon trees (five years or younger), it’s important to protect them from the frost by doing a couple of things. Check the weather forecast and get an idea of when the next frost will be. If possible, try to water the lemon tree at least 48 hours before the next frost then cover them with a frost blanket. The covers should be made of materials that will allow the lemon trees to still breathe, but also provides enough insulation to prevent plant frost.

For older lemon trees, we would recommend wrapping the trunk in several layers of cardboard to insulate it against the frost. Another simple trick is to string outdoor Christmas lights along the lemon tree branches to add as much warmth as possible.

If you are growing your lemon trees in containers then it’s also possible to move them indoors during the winter season. You should, however, allow the lemon trees to acclimatize by moving them indoors a few weeks before the first expected frost. When they are placed indoors, it’s important to find a spot that’s relatively cool and sunny (next to a south-facing window).

Losing Leaves from Over-Watering

In addition to the cold temperature, your lemon trees may also be losing their leaves due to over-watering. The roots of the lemon tree can start to rot if there’s too much moisture in the soil. This, in turn, can cause the leaves to turn yellow and gradually fall off.

You should still be watering your lemon trees throughout winter but at a lesser amount since the rate of evaporation will be much slower with the days shortening and temperature dropping. As a general rule of thumb, you may only need to water the lemon trees once a week for them to survive.