Lemon trees in pots can suffer from problems if they are not fertilized appropriately, from under or overwatering, a lack of sun or pest and fungal attack. Lemon trees in pots need the perfect balance of sun, water and nutrients to grow lots of dark green leaves and lots of lemons. Treating pest and fungal problems is essential to keep a lemon tree growing well in a pot.
This article will explore the top 9 problems with lemon trees in pots and how to solve each of them. Have a look through the list to see if any of these are affecting your tree.
1. Yellow leaves
Yellow leaves are a common problem for potted lemon trees. It is by a lack of nitrogen. Nitrogen is needed by the plant and leaves to develop chlorophyll which allows the plant to produce their own food and grow bright green leaves.
Make sure potted lemon trees are fed with pelleted chicken manure at the start of every season. This will replace the nitrogen used up and make sure the tree has enough to add new, healthy growth.
Another cause of yellowing leaves is a lack of water. Leaves will often turn yellow on the edges which then extends across the whole leaf. Deep water the pot across the whole surface of the soil until water drips through the drainage holes.
Water the plant with a dose of seaweed solution to help the plant to recover quickly and support healthy root growth.
2. Green veins and yellow leaves
Lemon tree leaves with green veins while the rest of the leaf is yellow is a sign of iron deficiency. This will usually start on the youngest leaves first and is common in potted lemon trees that are not fertilized frequently.
Treat this problem by giving the tree a diluted solution of iron chelates. Iron chelates can be bought in powder or liquid form. Do this each spring to prevent this problem. You can also feed the plant with citrus food throughout the year to replace the iron instead.
2. Brown leaves
Brown leaves can occur on potted lemon trees due to sunburn or a lack of water. New leaves can be burnt by the harsh summer sun. Lemon tree leaves can also burn quickly if the plant has been moved from shade into harsh sun.
It is ideal for lemon trees to get at least 6 hours of sunlight. If your tree has been in shade, gradually move it out into a sunny position to allow it to adjust to the intensity of the sun.
Brown leaves on potted lemon trees can also be caused by a lack of water. Potted lemon trees will need to be watered more regularly than those in the ground. Check the soil and water up to 2-3 times per week in summer. Shade the pot by surrounding it with smaller pots to stop it drying out so fast.
3. Drooping leaves
Drooping leaves on potted lemon trees is a common problem and is caused by a lack of water. A hot summer day can cause the leaves to droop in a few hours. The soil will feel dry at least 2 inches down.
Water the tree at the end of the day deeply and thoroughly with a hose. You can prevent this problem by watering the tree the night or morning before a hot day. This will make sure the soil is moist before the weather heats up. Surround the tree with bark mulch to stop the water evaporating too quickly.
4. Fungal growth
Fungus can grow on the leaves and can look gray, black or white. Sooty mold is most common and will look like a gray covering on the leaves. It is caused when excess moisture sits on the leaves. This can happen if the tree is watered from the top or if the weather is hot, humid and rainy.
It is best to prevent this problem by watering at the base of the tree instead of on the leaves. Keep the tree well trimmed and make sure it has good air movement. You can trim off the affected areas so the problem doesn’t spread, and this will help to avoid using fungal sprays to treat the problem.
5. Slow growth
Many people notice that lemon trees can slow their growth when grown in pots. This can be due to a lack of nutrients, water or poor potting soil. To get the fastest growth possible, choose large pot to give the tree space to grow.
Choose a top quality potting soil that contains a slow release fertilizer and lots of organic matter for good drainage. Place the tree in a position that gets at least 6 hours of sun and water it regularly.
6. Dropping flowers
Potted lemon trees can drop flowers meaning they will produce less fruit. Lemon trees will naturally drop excess flowers as the tree will always grow more flowers than it can hold as full grown fruit.
Lemon trees can drop flowers if they are not being pollinated. Place your potted lemon tree in an open area where they can be pollinated by insects or the wind. For indoor potted lemon trees, take a small paintbrush and move pollen from one flower to another to help with pollination.
7. Not growing flowers or fruit
If your lemon tree does not grow flowers or fruit at all it could be too young. Lemon trees will usually start producing flowers and fruit in their third year so if you have a small tree you may need to wait.
If you have an older tree and no flowers, add a flower and fruit promoting fertilizer this will give the tree more potassium and phosphorus. This promotes flowering by decreasing the nitrogen to potassium to phosphorus ratio.
8. Fruit drop
Fruit dropping from potted lemon trees before they mature can be caused by a lack of water or sudden temperature changes. A rapid change in temperature or stress on the tree can cause it to drop its fruit.
If you see a very hot day coming, water the tree well the night before and protect it from the afternoon sun. This can help to prevent it drying out quickly and dropping fruit.
9. Pest attack
Lemon trees in pots can be attacked by a variety of pests that can affect their growth and fruit production. Check out the most common pests affected potted lemon trees below.
Aphids are a common pest that can attack lemon trees in pots. They are a small, green bug that sucks the sap from the stem and the leaves. Aphids can increase in numbers quickly so squirt them off with your hose or treat them with neem oil.
Scale bugs will sit where the leaf joins the stem and will suck sap from the lemon tree. This will damage new growth and the leaves attached. Scale will form a hard coating over their body and attack themselves tightly to the stem.
To remove them before they have attacked, squirt them off with your hose or wash the stems down with some soapy water. Apply neem oil to the bugs and the leaf areas affected. Repeat this again in 1-2 weeks if the bugs are still there. It can take multiple applications to treat this problem.
Bronze Orange Bugs
Bronze Orange Bugs (or stink bugs) are sap suckers that will attack new growth on your lemon tree. They can reproduce rapidly in spring and summer and damage the tree quickly. To remove these bugs, squirt them off with a hose, shake them into a bucket of soapy water or treat them with pest oil.
Always wear eye protection and gloves as these bugs excrete a sticky, smelly substance that can irritate eyes and skin.
Key to healthy lemon trees in pots
Here are the key factors for keeping your lemon trees happy and healthy in a pot.
1. Soil and pots
Choose good quality soil that drains well and a large pot. Good quality potting soil will contain a slow release fertilizer to feed the tree for the first 3 months. A large pot will stay moist for longer and prevent the tree drying out.
Always put a potted lemon tree in a bright sunny position that gets at least 6 hours of sunlight.
Potted lemon trees will need regular water and more than those in the ground. In summer you may need to water every 2-3 days and 1-2 times per week in spring and fall. Larger pots will stay moist for longer but small pots can dry out quickly.
Check the soil with your finger and if it is dry 2 inches down, water it well. Look out for drooping leaves and water it deeply at the end of the day if this occurs.
Avoid getting water on the leaves and only water at the root base. This will avoid getting the leaves wet and causing fungal growth.
Water potted lemon trees regularly to keep them healthy. Give them a handful of pelleted chicken manure at the start of each season, 4 times per year. Give them some trace elements and iron chelates at the start of spring to prepare the tree for fruiting over the summer.
Alternatively, give the tree citrus food in spring and again in summer. This will provide the trace elements and iron the tree needs to grow healthy stems, leaves and fruit.
Problems with Lemon Trees in Pots | Summary
Lemon trees in pots need lots of care and are totally dependent on you to give them the nutrients they need. Common problems are caused by a lack of nutrients that can be prevented by feeding them regularly. Always water your tree during the summer and you will be rewarded with lots of flowers and fruit.
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.