Lemons will go soft on the tree if they left on for too long and overripen. Lemons can also go soft on the tree if they get too much water from excessive rain or from overwatering. Water on the leaves and fruit can also cause mold or fungal growth which can cause the fruit to go soft.
Soft lemons should not be eaten because they could be rotten, overripe or contain fungus or mold. Put soft lemons in your compost bin if they are not affected by disease or throw them in the bin if they do.
This article will explore why lemons go soft on the tree including the top 5 causes and solutions.
1. Lemons are left to for too long on the tree
Leaving lemons on the tree for too long can cause them to overripen and go soft. Lemons take around 6 months to grow from the time they are a bud to ready to pick. The color of the lemon skin will develop over time but is dependent on how much sun and warmth the tree gets.
It is possible to have a ripe lemon that still has green skin. Picking lemons when they are ripe, heavy and smell fresh and lemony is important to stop them going soft. Feel the lemon and if it feels heavy then it will be full of juice and ready to pick.
Lemons can last for up to 2-3 months after picking. Place them in the bottom of your refrigerator and they will keep for months.
2. Lemon trees are getting too much water
Lemon trees that get too much water can develop soft fruit on the tree. Very rainy summers or hot humid weather can cause the fruit to turn soft very quickly. A rapid change from dry weather to wet can also stress the tree. It can absorb water quickly and the fruit can soften.
Too much water can also cause damage to the tree roots reducing the oxygen in the soil and can cause root rot. Fungal growth on the roots can affect the tree’s growth and cause problems with the developing fruit.
To avoid this it is important to water the tree deeply but less regularly. Rather than watering every day, water the tree deeply twice per week in summer and reduce this to once every 2 weeks in spring and fall.
Watch the weather and reduce your watering if you are getting a lot of rain. Surround the tree with 3 inches of bark mulch to absorb the excess water and stop the soil from splashing on the leaves. This will reduce the risk of fungal growth.
Very rainy weather or water on the leaves and fruit can cause fungal or mold growth on the plant and fruit. This can cause the fruit to go soft. Look out for brown, black or green spots.
3. Lemon trees are not getting enough water
A lack of water can cause fruit on lemon trees to go soft. A stressed tree will divert water from the leaves to the center of the tree which can cause the fruit to go soft.
Potted lemon trees are more likely to suffer from a lack of water compared to trees grown in the ground.
Water potted lemon trees when the soil has dried 2 inches below the surface. Cover the surface of the potting soil with bark mulch and shade the base of the pot by surrounding it with smaller potted plants.
For more tips on watering lemon trees, check out my articles: How Often to Water a Potted Lemon Tree | Once Per Week in Summer and Overwatering a lemon tree | 6 Ways to know + Solutions.
4. Lemon trees have developed mold or fungus
Mold and fungus can grow on lemon tree leaves, stems and fruit if there is very wet weather, if you are watering from above on the leaves or if it has been transferred from another tree. Fungal growth can look like brown, black or green spots on any part of the tree.
Fungus can affect lemon fruit growth and can cause it to soften. It is best to avoid eating any fruit that has been affected by fungus growth. Remove the affected fruit and throw it away rather than putting it in your compost to avoid spreading the fungus.
For large fungal infections, a fungicide is usually the only way to get rid of the problem. Trim off the excess leaves that are affected to minimize the problem area. Only remove up to ¼ of the leaf coverage to avoid stressing the tree.
There are many different fungus types which can be tricky to identify. Brown spots on lemons for example are usually caused by a fungal growth and is called ‘Lemon Scab Disease’. You will notice that there will be brown spots or ‘scabs’ on the fruit, stems and leaves. While you can use the juice from the fruit, do not use the skins. Treat the fungal disease with fungicidal spray to fix this problem before it spread to other trees.
5. Excess fruit on the lemon tree
Another reason why lemon fruit will go soft on the tree is when the tree us unable to hold the fruit it is growing. Lemons will naturally drop excess fruit as they will produce more fruit that they can carry to full size. The excess fruit will soften and drop off the tree as it develops larger.
This is a normal process and is not a problem. The tree will continue to develop the fruit that it can carry. Pick fruit when it is ripe to encourage the tree to grow more flowers in spring.
Why Lemons Go Soft on the Tree | Summary
Lemons will go soft on the tree if they are left on too long and become overripe. Pick the lemons when they feel heavy with juice. Too much water can also cause the lemons to go soft. Take care when watering and add mulch to absorb excess rain.
A lack of water can also stress the tree and cause the lemons to go soft. Look out for fungus and mold growth and treat the problem to prepare your tree for the next healthy crop.
I am an accredited practicing dietitian, experienced gardener and a dedicated cook. I love writing and sharing my experience so you can learn from my successes and mistakes.