Your orange tree dropping fruit when it’s unripe may be for several reasons. It’s up to you to decide if the reasons are natural (e.g. self-thinning), environmental (e.g. plant stress) or how you’re caring for the plant (e.g. watering), which is one of the more common reasons. Read on to decide which problems your citrus tree has and how to fix them.

Natural occurrences that leads to oranges shedding fruit early

Self-thinning

Most cultivars of orange trees produce too many flowers and buds that lead to too many oranges for the size of the tree. If you don’t remove some of the oranges yourself to give the remaining ones a better chance at full growth, the orange tree naturally drops fruit before they’re ripe.

What to do

Remove enough unripe and small oranges to give those that remain a better chance of successful growth.

Harvest time

Not all orange tree cultivars ripen at the same time. If your fallen oranges look ripe, perhaps your orange tree has a different harvest period to most trees.

What to do

Look up your orange tree cultivar on the internet and check when its harvest time is due. the orange tree dropping fruit may be just at the right time.

Environment reasons orange trees drop their fruit

Any form of plant stress can trigger the tree into dropping oranges before they’re ready to harvest. Here are some of the common reasons that do cause premature fruit dropping

Fruit split

Fruit split is when the inside of the orange grows faster than the skin and splits the skin. This happens quite often in some orange varieties such as Valencia and tangerines. Fruit split causes the oranges to fall from the tree. Over-watering and high temperatures are the issues behind this problem.

What to do

Monitor the conditions around your orange tree, especially when it’s outside in the summer and early autumn. See How to grow and care for orange trees for more details.

Remove split fruit when you notice it, as the split encourages the arrival of aphids (See Orange tree pests and diseases.)

Temperature changes will cause oranges to drop early

Any plant stresses out with an extreme change in temperature. Don’t move your orange tree from a cold to a hot environment, and vice versa. The tree also can’t handle cold temperatures, such as frost. This is the danger in the early autumn if you leave your orange tree outside overnight and there’s an expected early frost.

What to do

Monitor the temperature around your orange tree closely, particularly when it’s outside. If it does experience frost, move it slowly into progressively warmer environments. Don’t bring it into a warm room in one step. If you grow orange trees in pots this is much easier to do for obvious reasons.

Pests and diseases

As with any house plant or citrus lemon trees, orange trees are susceptible to infestation by bugs and infection by diseases.

What to do

I explain the most common ones, especially aphids, in Orange tree pests and diseases and give help on how to deal with them. It may take some detective work on your plant to find if your orange tree has this problem, but it’s worth it for a healthy plant.

Physical injury

Any form of physical injury stresses a plant out and can result in the oranges dropping before their time. Physical injury includes being knocked over by a pet or a child as well as over-enthusiastic pruning of the orange tree and a cycle of over- then under-watering the plant.

What to do

Place your orange tree somewhere safe and out of the way. Be gentle and consistent in how you (and everyone) interacts with it. Use tree wrap to help support any broken branches, or prune off the broken bits. Remove any dead or diseased parts of the tree (sterilise your cutting tool first) the moment you notice them.

Care and maintenance

Watering

In most cases of an orange tree prematurely dropping oranges, it’s due to under-watering. The roots and leaves dry up, and the fruit can’t get enough moisture to develop fully. However, over-watering has the same effect and can cause root rot, along with the leaves turning yellow and falling off.

What to do

Even if you don’t think you’re over-watering your orange tree, the soil may be soaking wet due to poor drainage so check that there are enough drainage holes in the bottom of the pot. You may need to repot your orange tree to dry it out.

As for under-watering, wait until just the top 3cm of the soil is dry and then water the plant thoroughly.

Fertilising

Oranges falling before their time could be symptom of nutritional imbalance. The orange tree may not be receiving enough nutrients and micronutrients. Or there may be an imbalance of nitrogen which encourages foliage growth at the expense of the fruit. In this case, the fruit doesn’t receive enough nutrients for growth and falls off.

What to do

Review your fertiliser and the schedule you apply it on. If you use compost as your potting soil, remember that that also provide minerals for your tree. Err on the safe side by using a fertiliser designed for citrus trees.

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