My parents have a Meyer lemon tree in their backyard, and they 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?
The most common reason why lemons split is due to a sudden change in watering. If their soil is dry and quickly gets a large watering, the tree sends excess water to ripening fruit, which quickly expands the rind. This expansion causes lemons with weaker rinds to split.
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, but it can also be from a change in weather, lack of nutrients, and disease. To identify why your tree has split lemons, it’s best to start by checking the watering it receives. Next, look to see if there has been any extreme weather lately.
While it can be 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.
So, what are all the reasons why lemons split while on the tree?
- Change in watering
- Change in weather
- Lack of nutrients
As mentioned, the most common reason is due to a change in watering, but it’s important to consider the other causes. Let’s explore what these issues mean and how you can reverse them to get your lemon to stop producing split or cracked fruit.
How To Fix Split Fruit on Lemon Trees
If the tree has gone through a mini or full 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 only 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 to it will cause it to swell. The weakened rind will then split.
Fruit is how lemon trees reproduce, so it’s in the tree’s best interest to keep it alive. And since the majority of fruit is made of water, it makes sense why giving a thirsty lemon tree heavy watering can cause the lemons to split.
So, how do you water lemons trees to prevent split fruit?
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. A soaker hose or drip system is ideal when deep watering lemon trees.
Like all citrus trees, lemon trees do best with deep watering. This is because lemon trees are subtropical and have evolved with heavy rainstorms that thoroughly soaked the soil. They’re not designed for areas with drought or sporadic rain showers.
Deep watering also encourages the tree to grow deeper roots. This is because the tree’s roots are designed to seek out water in the soil. If you only shallowly water the tree, it will grow shallow roots. If you deep water, the tree will grow deep roots to access the deeper water.
So, deep watering is beneficial for:
- Better anchorage in high wind
- Access to deeper water tables
- Increased drought-resistance
- Holding more water in the soil (which means you can eventually water less often or not at all!)
So, along with little to no split fruit, watering lemon trees in this way can help them become more self-sufficient. A lemon tree that has stronger and deeper roots means you don’t need to do as much in times of high winds and drought. That sounds like a good deal to me!
Avoid Extreme Weather
While it’s not as likely as splitting from a change in watering, extreme swings in temperature (and sometimes wind) 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, the rinds won’t be as elastic, and 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).
Provide Balanced Fertilizer
Lemons can also split from a lack of nutrients. This is because lemon trees often bear heavy fruit loads. 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. Since the trunk, branches, roots, and leaves are vital for the tree to properly absorb water and nutrients, the less important parts such as flowers and fruit will be one of the first things the tree will sacrifice. This leads to the tree shedding or poorly developing its flowers and fruit. After, the leaves can turn yellow and also begin to shed.
To remedy this, feed your lemon tree a fertilizer that has twice the nitrogen to phosphorus and potassium (the other two main nutrients, all known as NPK). For example, a fertilizer that has an NPK of 6-3-3 is great for lemon trees.
Two other important nutrients for proper fruit development are potassium and calcium.
Since potassium is one of the three main components of lemon fertilizers (K), you don’t need to worry about it as much if you’re using a quality fertilizer.
On the other hand, calcium is a secondary ingredient, and some fertilizers might not have sufficient levels.
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, so they’re a great way for your tree’s soil to get a natural and healthy boost of this nutrient.
If you’d like to learn more about eggshells for citrus trees, as well as lemon tree fertilizers, you can check out my other post on using eggshells and my page on which citrus tree fertilizers I recommend.
It can be difficult to know what nutrients your lemon tree’s soil is lacking, so performing a quick test on it can go a long way. To see how to test your lemon tree’s soil for potassium (as well as nitrogen and phosphorus), check out this video by California Gardening.
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.
Prune Excess Growth
Aside from applying a quality fertilizer, another way you can make sure your lemon tree’s fruit has enough nutrients and water to go around is to prune the excess fruit.
Like most other fruit trees, lemon trees often produce an overabundance of flowers and fruit. It’s fairly common for the majority of the lemon tree’s flowers and fruit to fall off before fully fruiting. This is so common that it’s referred to as “June Drop”. As you might have guessed, this event typically occurs in June.
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 towards the fruit that will actually fully develop? There is, and the answer is pruning.
The act of pruning excess flowers and fruit naturally reduces the resource demands for the lemon tree. This 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 therefore, crack and split less often.
But what do you prune, when do you do it, and how is it best done?
What To Prune on Lemon Trees
You should prune an excess of:
Since flowers develop into fruit, you shouldn’t need to prune any fruit (just excess flowers and branches). However, if you’re a little late to the pruning game, pruning some of the developing fruit clusters will still help redirect energy to the remaining fruit.
When To Prune Lemon Trees
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.
How To Prune Lemon Trees
I’m more of a visual person, and something like how to prune lemon trees is usually best shown with a visual guide. Because of this, I’ll include a video below by IV Organic if you’d like a quick guide on how to prune.
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, simply disposing of it in the trash or burning it will work.
The rind is actually 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.
More Tips To Reduce Split Lemons
While some of the best ways to prevent split fruits on your lemon tree are to check the water, weather, nutrients, and pruning, there are a few more ways that can help. Here are some extra tips that will make these methods easier and more efficient.
- Compost – Provide a 1-2 inch layer of compost on the top of the lemon tree’s soil will help keep the soil rich and full of nutrients. Even though compost is usually slightly alkaline, and lemon trees prefer a slightly acidic soil pH (6.0-7.0), compost is a near-perfect fertilizer. To increase the acidity of compost you can add coffee grounds, pine needles, peat moss, or sand. Sometimes, you won’t even need to purchase a store-bought fertilizer if you’re using fresh and quality compost. Just make sure the compost isn’t touching the trunk directly as this can introduce mold.
- Mulch – Providing a 1-2 inch layer of mulch (on top of the compost if you’re doing that too) will help the soil retain water and block the sun from drying it out. There are many mulches out there, but some of the most common are grass clippings, leaves, bark, and pine needles. When water evaporates from the soil, the mulch will catch most of it and lock it in the soil. Similarly, since citrus trees are grown in hotter regions, it’s a good idea to provide mulch as protection from the sun. Hot and dry days can dry out soil in a matter of hours. Mulching provides a physical barrier to the heat, which means the soil can stay alive and doesn’t need to be watered as often (sometimes not requiring any watering outside of rainfall). Just make sure the soil is also well-draining so it doesn’t get water-logged and develop root rot.
Photo credit: Neil Sperry