Meyer Lemon Bush Leaves All Drop Off

Question: We have a Meyer Lemon and Key Lime bush (in the house) that have both had basically all of their leaves drop. The Lemons are staying on but are small, and the lime never produces anything, though it does have a bit more growth coming in. Any suggestions on what to do? We do mist they daily, they get fertilizer about every 6 weeks. They are also in a sand/pet/potting soil mixture. Any suggestions would be greatly appreciated.

responder: The Question Asker Replied March 20, 2023, 6:49 PM EDT
response: Also, funny thing with the Key Lime, it is showing green growth on the lower portion of it for the first time since we have had it. We have had this plant since mid November.

responder: Thank you for your question! Nancy M.MSU Extension Advanced Master Gardener  Replied March 23, 2023, 1:17 PM EDT
response: Since you mention specifically that the leaves are dropping off of both the Meyer Lemon and the Key Lime trees, I will address that issue primarily: First of all, it is easy to overwater Meyer lemons: Overwatering saturates the tree and the soil around it causing nutrient deficiencies and diseases. The main sign of overwatering is yellowing and leaves falling off the tree. Overwatering the lemon tree may stop the roots from functioning properly, causing harm to the plant in the end. To fix the overwatering problem, use a slightly wider pot that is not too deep because the Meyer lemon tree has shallow roots. Ensure that your pot drains well and fas,t then repot the lemon tree in a well-draining soil mix. Water regularly for the first week or so then once or twice a week in the next couple of months to fix the overwatering problem. However, there are other factors which can stress the tree and cause leaf drop: nutrient deficiency, root rot, extreme temperatures, and overly dry soil. Leaf loss can be reversed if the issue is resolved quickly. Citrus trees dropping their leaves is not a normal pattern for citrus trees; citrus trees like orange, lime, lemon, and grapefruit are evergreen, which means they don’t lose their leaves in the fall as many trees do. If your citrus tree is dropping more leaves than necessary, it could be a symptom of root rot. Root rot is usually caused by overwatering, which creates an environment for a fungal infection to develop in the roots. You may not be needing to mist these plants on a daily basis. Overwatering can easily occur when your citrus tree has poor drainage. For this reason, potted citrus trees are the easiest to overwater as they’re notorious for not having great drainage. If your potted citrus tree has water that’s sitting for too long, and root rot begins to take hold, repotting your citrus tree with fresh soil is likely the best bet. Because drainage is so important, make sure your pot has good drainage and that you’re using well-draining soil. Another common cause for leaves yellowing and dropping is temperature fluctuation. Citrus trees love warm weather, but they prefer it mild. If it’s too hot or cold, the trees can become stressed and start to shed leaves to protect the rest of the tree. Generally, citrus trees prefer temperatures above 30ºF and below 90ºF. The lack or loss of essential nutrients from the soil and the citrus tree can also cause leaves to yellow and drop. Additionally, it can slow or prevent flower and fruit production. These vital nutrients include nitrogen, iron, magnesium, zinc, and manganese. The best way to supplement your citrus trees is with a high nitrogen fertilizer. The nitrogen should be twice as much as phosphorus and potassium. The amount of fertilizer to use depends on the size of your tree and the type of fertilizer you buy. Fortunately, most store-bought fertilizers provide calculations on the back of the package. Remember that potted citrus trees need less fertilizer since they have a finite amount of soil to work with. Be careful about overfeeding your citrus trees as a high concentration of nutrients (and especially nitrogen) can burn the roots and cause leaf drop, slowly killing the tree. You mention that you are fertilizing about every six (6) weeks; that may be too frequently. Refer to the two attached articles for more information about this and other details for how to care for your plants. Pests like scale insects may also be one of the reasons for leaf drop in citrus trees. You can remove these pests from the leaves with the help of a sharp knife or a blast of water from a hose. You can also get a cotton swab, soak it in alcohol, and wipe it on the affected areas.  Will Citrus Tree Leaves Grow Back? Yes, it is likely that the leaves will grow back on your citrus tree(s) after a few of them have fallen off. Developing buds are the first sign that your tree is on the road to recovery. You say that this already happening for your Key Lime tree.  I hope this and the attached information will help you determine and address the cause of the leaf drop.

responder: The Question Asker Replied March 24, 2023, 6:50 PM EDT
response: Thank you. I'll take a look at this. I'll probably repot both of them. One is showing signs of new growth at least, so I think that's a good sign. The Lemon tree with the lemons on it though has no signs of new growth at all. Now I know what I'm doing this weekend.