We have a lemon tree in our backyard, and occasionally get a split or cracked lemon. While it didn’t affect too many fruits, it got to the point where it prompted some investigation. So, why do lemons split?
Lemons split due to a sudden change in watering. During drought, lemon fruit shrivels to reserve water. When the tree suddenly receives a large amount of water, it sends it to the weakened fruit, causing it to expand quickly and occasionally split. For best results, only water when the top 2-4 inches of soil is dry.
While a change in watering is the main reason why lemons split, what are some other factors, and what can you do to prevent this issue moving forward?
Why Do Lemons Split?
Lemon trees most commonly get split fruit due to a change in watering or a change in weather.
If the tree has gone through a drought, and then suddenly finds itself with an excess of water, one of its priorities will be to quickly provide water to the dying fruit.
The problem with this is that if the lemon’s rind is too thin or dry from the drought, the sudden volume of water that’s pumped into it will cause it to swell. The weakened rind will then split.
Splits are also the results of a lack of nutrients and disease.
While it’s frustrating to get split lemons, it’s important to identify what issue could be causing it so you can provide the right solution for your tree.
Let’s explore what these issues mean and how you can reverse them to get your lemon to stop producing split or cracked fruit.
4 Ways to Fix Split Fruit on Lemon Trees
1. Avoid Under-Watering
The best way to water your lemon tree is to only water when the top 2-4 inches of soil is dry. I check this by pushing a finger into the soil. This method helps prevent both under and over-watering.
Once the top 2-4 inches of the lemon tree’s soil is dry, use a hose on a low flow setting and keep it about one foot away from the trunk. Let the water run for 20 minutes. For potted lemon trees, slowly water until it flows out of the bottom of the pot.
Lemon trees are subtropical and evolved with heavy rainstorms that thoroughly soaked the soil. They’re not designed for areas with drought or sporadic rain showers.
It’s important to avoid the soil getting bone dry, so the fruit rinds don’t become weakened and eventually split when there’s a sudden increase in water.
This method of watering will also encourage stronger and deeper roots. A lemon tree that has established roots means it’s more independent during high winds and drought.
Here are more ways you can avoid the soil from getting too dry:
- Provide partial shade. Lemon trees evolved as understory plants, so they prefer the partial shade of trees. If possible, provide your lemon trees with at least 2 hours of shade during the afternoon.
- Apply 2 inches of compost. Compost increases the organic matter of the soil. Every 1% increase in the soil’s organic matter leads to an additional 20,000 gallons of water held per acre.
- Apply 4 inches of mulch. Mulch keeps the soil covered, providing essential protection from the sun, wind, and erosion. It also feeds earthworms, mycorrhizal fungi, and the like, which provide many benefits to plants.
2. Avoid Extreme Weather
While it’s not as likely as splitting from a change in watering, extreme swings in temperature can also cause lemons to split. This is because heat expands the fruit while the cold contracts it.
When fruit gets warmer, it expands. And when it gets colder, it contracts. If this happens too fast, since they’re already weakened, they’ll split.
Strong winds can also dry out the fruit, causing the rind to shrivel and crack. When the tree sends more water to these fruits, the cracks expand and can split down the entire lemon.
While you can’t control the elements, there are a few things you can do when the weather gets a bit extreme:
- Provide afternoon shade from the sun on extremely hot days (over 95ºF)
- Cover the tree in times of frost (below 32ºF)
Additionally, on hot days, consider painting the lemon tree’s trunk white. This will help it reflect heat and keep it cool.
If you have a potted lemon tree, you can simply bring them indoors in times of extreme weather and wait it out (keep it by a sunny window in the meantime).
3. Provide Proper Nutrients
Lemons can also split from a lack of nutrients. If there aren’t enough nutrients to go around, some of the fruit might be misshapen or poorly developed. This means the rind will likely be weaker and thinner and have a higher potential to split.
So, what nutrients should you be providing your lemon tree to avoid split fruit?
The most important nutrient for lemon trees is nitrogen. Lemon trees are heavy nitrogen feeders and rely on this nutrient for just about every part of the tree—its trunk, branches, roots, leaves, flowers, and fruit. When lemon trees don’t have enough nitrogen to go around, all parts of the tree will suffer.
Calcium, potassium, and iron are other beneficial nutrients to lemon trees, and some fertilizers might not have sufficient levels.
Recently, our lemon tree had an iron deficiency due to the yellow leaves having green veins. To help fix this, we’re using an organic fertilizer, which has plenty of iron. To be safe, we’re also supplementing with kelp (high in iron and potassium).
So, along with a quality fertilizer, provide your lemon tree with extra calcium to help reduce split fruit. A great way to do this is to fertilize your tree’s soil with eggshells. Eggshells contain 95% calcium.
How to Fertilize Lemon Trees
Provide lemon trees with either fertilizer or compost. Apply the fertilizer as directed or 2 inches of compost every 1-2 months.
While chemical fertilizers are good in the short term, they often have long-term effects such as drying out the soil and killing off soil life, making it more difficult for the plant to survive.
Alternatively, compost provides more than enough nutrients for plants and builds the soil’s health—bringing other benefits such as increased nutrient uptake, water retention, and erosion prevention.
Even though nutrients are essential, a balanced soil pH is needed for proper nutrient uptake. Lemon trees prefer a soil pH of 6.0-7.0. The best ways to check your soil’s pH are with pH strips or a meter.
Overall, it takes a lot of nutrients for a lemon tree to grow properly, and this includes its fruit. If a lemon tree is short on nutrients, it won’t have enough to properly develop the fruit or its rind, which can lead to more split fruits.
4. Prune Excess Growth
Like most other fruit trees, lemon trees often produce an overabundance of flowers and fruit.
The only problem is, the lemon tree uses a lot of nutrients and energy to provide this heavy yield of flowers and fruit, only for most of them to fall off prematurely.
So, is there a way you can help the tree redirect these nutrients toward the fruit that will actually fully develop? There is, and the answer is pruning.
Pruning excess flowers and fruit helps conserve the tree’s water, nutrients, and energy and redirect it to fewer, select fruits. Because the tree then has more nutrients to go around, there’s a greatly reduced chance the fruit will be underdeveloped, and crack and split less often.
But what do you prune, when do you do it, and how is it best done?
You should prune an excess of:
- Branches
- Flowers
- Fruit
The best time to prune is after the last frost, but before the growing season (typically early spring). This is because the tree will need time to heal from the wounds.
If you prune too early, the tree will have a hard time trying to both heal and survive through the frost. If you prune too late, you could miss the fast healing and the growth spurt that comes during the growing season.
To prune your lemon tree, take your disinfected pruning shears and cut any dead or excess branches. Remove the suckers or sprouts growing out of the base of the tree. When you make a cut, make sure it’s outside of the branch bark ridge.
What Should You Do With Split Lemons?
Prune and remove the split lemons to prevent mold, fungus, disease, and pests from infecting the tree or spreading to other fruit. These split fruits can usually be composted.
However, if there’s mold or fungus already growing, it might not be best to introduce it to your compost pile as it can spread throughout the soil and to other trees. In this case, disposing of it in the trash or burning it will work.
The rind is a natural way to protect the fruit from mold, fungus, disease, and pests. So when this is split, and the fruit is exposed, the tree’s immune system is slightly exposed. It’s almost like how we get a cut and have the potential for it to get infected.
Can You Eat Split Lemons?
Split lemons can be eaten, but it’s usually not a good idea. Since the fruit is exposed, this can invite disease or pests into the fruit and could in theory make you sick.
If you’d still like to eat the fruit, first check that it’s not infected and consider pruning the split from the rest of the fruit.