Your orange tree losing its leaves could be a natural occurrence or could be the sign that there’s a problem (or two) with the tree. Read on to see if any of these issues relate to your orange tree’s environment and care, as they could be the cause behind the leaf loss. The most common reason is draughts, the temperature is too cold or too warm as well as overwatering and even underwatering. That being said there are more reasons which I also cover below.

Outgrowing its container (root bound)

Every three or so years, you need to move a healthy orange tree to a larger pot as it outgrows its current one. A sign that it’s time to do this is that the tree starts losing its leaves. The roots are all bound up together and can’t send enough water and nutrients to the branches and leaves. The main issue is that there is not enough soil to retain moisture, so even when you water them regularly, the water drains around the edge of the roots and out the bottom of the pot. Another sign of this is curling leaves and well as yellowing leaves.

What to do

Repot your plant. You can find the step-by-step instructions for this in How to grow orange trees in pots.

Change of light usually because you have placed in a new positon

Have you just moved your orange plant outside for the summer or inside for the autumn? Or perhaps you’ve turned on grow lights for the winter months? Any change in the type or amount of light throws your orange tree into a short time of stress and can result in it losing its leaves.

What to do

As long as the new light conditions are favourable to the orange tree, just wait things out, and the leaf dropping should end. The new leaves that develop will like the new light conditions. Orange trees can be a little temperamental, so they can shed some leaves once moved to a new position.

Extreme change in temperature

If it’s autumn and your orange tree is still outside on your patio or deck, an early frost could affect the leaves. An extreme change in temperature makes an orange trees lose its foliage.

What to do

At the turn of the seasons, closely monitor the predicted day and night temperatures. Move the orange tree inside your home or greenhouse when the temperature is going to fall outside its preferred range 8˚C  (night) to 27˚C (day).

If your orange tree has experienced frost, move it into gradually warmer environments rather than directly into your warmest room.

Draughts

Along with the changes in temperature comes the idea of draughts. This can happen in the home from a door or a leaky window. Or in the garden if your orange tree pot is in a wind tunnel. The leaves often turn yellow before they fall off.

What to do

Check for occurrences of wind around your orange tree. Either move the pot to a more sheltered location or put up a barrier. In the home, be alert to dry draughts from central heating in the winter.

Over- and under-watering

Water stress is the most common cause of an orange tree losing its leaves. While over- and under-watering both cause the leaves to turn yellow and fall off, the most harmful is alternating between them.

What to do

See the Water section of How to grow and care for orange trees for all the information on when and how to water your plant. In addition, check out the Root Rot section of Orange tree pests and diseases for how to get rid of this fungal disease caused by over-watering.

Pests and diseases

And speaking of pests and diseases, these are frequent causes of orange trees losing their leaves. Sap-sucking bugs in particular, are partial to orange tree leaves, but both fungal and bacterial diseases tend to move in such as black sooty mould.

What to do

Put your mind at rest by checking out all the items in Orange tree pests and diseases to make sure that your orange tree is free of them. If you find that your tree has an infection or an infestation, the article provides advice on what to do.

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