The lemon tree, or by its scientific name citrus x limon, is a very popular fruit tree widely cultivated throughout the world. Although in natural conditions it can grow up to 4 m high, this fruit tree can be grown in a pot. This makes it possible for many people who don’t have a large garden to harvest a few lemons.
But growing this citrus in a pot usually brings some complications. And since on this website we want you to enjoy the best lemons, we bring you this post with the most common problems of potted lemon trees. We will try to explain the causes and possible solutions for each of these problems.
1. Caring for lemon trees in pots
In gardening, as in almost all activities, the best way to solve a problem is to prevent it. Therefore, before having to solve problems with your lemon tree in a pot, it is best to start by taking care of it correctly.
To do this, follow the tips below. I do not guarantee 100% that giving the best attention you will not have any problems, but without a doubt the chances of having them are reduced. And if you still have them, solving them will be much easier.
The key points to keep in mind whenever you grow a lemon tree in a pot are the following:
1.1 Pot Size
This is key with all houseplants, but especially with plants that can naturally grow to the size of a lemon tree. It will never fit properly in the pot if it is not the right size. We have dedicated a special post to this topic, go here for more information on the right pot size for a lemon tree.
1.2 Watering the lemon tree
As with the choice of pot, watering is another key point for any indoor plant. At this point, keep in mind that lemon trees need a lot of water, but without flooding the soil, as this could cause the roots to rot. In this way I can recommend that you water it every 2 days in spring and summer, and once a week in winter.
1.3 Potted lemon tree pruning
The right time to prune is when the plant is hibernating. That is, you can prune from late fall to early spring. Pruning should always be light, cutting dry, weak, diseased branches and those that have grown excessively.
1.4 Fertilizer for a lemon tree in pot
Since the lemon tree can only extract nutrients from the soil contained in the pot, it is recommended to pay once a year. It is best to do it in early spring. Go to the nursery and ask for a special fertilizer for citrus.
1.5 How many hours of light do you need
Lemon trees need many hours of sunlight. That is why it is good that you place it near a window or balcony, the ideal is that it receives about 5 or 6 hours of sun a day.
1.6 When to transplant
Logically a plant like the lemon tree needs to be transplanted with some frequency. In general, a transplant every 3 or 4 years will suffice, always moving to a larger pot. Although pruning can control the size of the lemon tree, there comes a point where repotting is unavoidable.
Lemon trees cannot tolerate temperatures below -2ºC, so if there are frosts below that temperature where you live, it is best to bring the lemon tree indoors.
1.8 Pests and diseases of the lemon tree
Periodic control of pests and diseases is very important. Lemon trees are very prone to being attacked by mealybugs, red spiders, leaf miners, aphids and diseases such as alternaria alternata, the virus of sadness.
2. Problems with lemon trees in pots
We have already seen how to take care of a lemon tree in a pot, but as I have already told you, taking care of it correctly does not completely free you from problems. Let’s go over the most common problems you can have when growing a lemon tree in a pot and how you can prevent or fix it.
2.1 Lemon trees in pots yellowing leaves
A problem that often appears in potted lemon trees is the yellowing of their leaves. The causes of this problem can be several, let’s see which are the most common:
- One of the main causes is the lack of nutrients, mainly nitrogen, magnesium or manganese. Being in a pot these nutrients are easily filtered. For this reason it is very important to fertilize correctly. In the case of a lack of manganese, the leaf does not turn all yellow, but is more mottled.
- The lack of irrigation for a fairly long period also leads to yellowing of the leaves. Follow the irrigation advice that we gave in previous paragraphs and you will not have problems.
- Returning to the nutrients, the lack of iron can also cause yellowing. In this case, it will affect the new leaves first and spread to the older ones. The clearest particularity of iron deficiency is that it starts in the veins and, when severe, the leaves will turn an almost white yellow. The solution is to apply fertilizer with iron in its formula.
- Finally the lack of zinc is also another possible cause. The lack of this micronutrient will cause yellowing, which, as with the lack of iron, will begin in the new leaves and spread to the old ones. Again the application of fertilizer with zinc can solve this problem.
As you may have noticed, in most cases, solving the yellowing of the leaves occurs with a correct fertilization.
2.2 Low temperatures
We already mentioned that lemon trees cannot withstand temperatures that are too low. If it is exposed to very low temperatures, the shoots will begin to freeze and if it is too low, it can even freeze to the roots.
The best way to avoid a problem like this is to bring the lemon tree indoors. If you don’t have a place under a roof to protect it, put a good thermal blanket on it. Although for very low temperatures these blankets are not very effective.
2.3 Improper container size
The wrong selection of a pot can cause many problems for the normal development of a potted lemon tree. Problems can be caused by a pot that is too small or too large. But when selecting the pot, not only the size matters, the material must also be taken into account.
When you plant the lemon tree, keep in mind that the size of the pot must be such that it allows the entire root system to enter without problems. And in addition, there must be a certain size left over so that in the future the roots can continue to spread. For example, for a small plant, no more than 40cm tall, a 20cm diameter pot will work just fine.
Again I recommend this post about the best pot for a lemon tree. Since here we did a little analysis, and there are many more details on this point.
2.4 Dropping flowers
As you well know, for your lemon tree to bear fruit it must first flower, but sometimes the plant can drop all or almost all of its flowers. Consequently, you will not have lemons to harvest.
Flower drop usually occurs naturally, as the fruit tree releases flowers, leaving behind as many fruits as it can produce in its full-grown state. In case the plant is not comfortable, you can drop all the flowers.
If you take good care of the lemon tree, that is, you give it the necessary nutrients, a suitable pot, good watering, etc. It will reduce flower drop.
Another key to controlling flower drop is making sure you can pollinate properly. For this, it helps a lot to take the lemon tree outside when it is in flower, so there will be insects and air currents that can help pollination.
2.5 Green veins and yellow leaves
If you read section 2.1 carefully, we already mentioned that the lack of iron usually brings problems to the lemon tree. The most notorious symptom of this problem is that you will be able to see the yellow leaves with the veins of the same green. If you do not solve this problem little by little the leaves will fall.
To solve this problem, the most recommended is to use chelates, that is, a supply of iron that can be applied by foliar fertilization (the liquid is applied to the stem or leaves) or radicular (by the root).
The chelate, in short, is an iron supplement that provides the plant with what it has not been able to assimilate by itself. In addition, this solution takes advantage of the iron in the soil that the plant had not been able to use.
2.6 Brown leaves
Generally, brown spots on a lemon tree are caused by sunburn. It is very common in potted lemon trees, especially when they receive the sun through a window glass. Try to avoid it, either by opening the window or moving the plant away during the most intense sunlight hours.
This happens especially in summer, when the sun’s rays are more intense. It is very difficult to see this problem in the fall or summer months. Make sure that the lemon tree receives about 5 or 6 hours of sun a day, but always bearing in mind that its leaves can burn due to exposure to strong rays.
2.7 Very slow growth
In good conditions and care, it can be said that the lemon tree is a fruit tree that grows quite fast. If you notice that your potted lemon tree grows very slowly, it is a sign that something is wrong.
The causes of a problem like this can be several. Although the most common is a very poor soil in nutrients, which can be solved with adequate fertilization. When transplanting the lemon tree, keep in mind that it is good to use new soil, rich in nutrients and with good drainage.
Another cause of a low growth rate is a pot that is too small. The amount of soil in the pot may be too small for proper growth. In addition, if it has been in a small pot for a long time, it will be causing a strangulation of the roots, this means that the plant does not grow at the rate it should.
2.8 Falling lemons
On certain occasions, lemon trees tend to release their fruit before they ripen. It can be a natural thinning where it only leaves the fruits that it can develop. If so, you should not worry, this is not a problem.
But if you notice that it is shedding too much fruit, leaving you with practically no lemons, you should be concerned. Although in general it is not a serious matter since the most common thing is that this fruit drop is due to the stress suffered by the plant.
Try to avoid sudden changes in the environment where you have your lemon tree. These sudden changes can be both in temperature and air currents. Avoid having a lemon tree in an environment with air conditioning or any heating system.
- Growing Citrus Indoors – .wisc.edu.
- Citrus in a Pot – ccmg.ucanr.edu.
- UNDERSTANDING CITRUS FRUIT GROWING – pdf.usaid.gov.