Q.What To Do About Yellowing Citron Leaves?
I read an article about your website about what to do about yellowing citrus leaves, but still need some help. Would love if you’d be able to help me out with a few questions I have. In October, I planted a few citron plants. Since it’s too cold outside, I have kept them inside with a grow lamp. I planted them with cactus soil (which is what I read is recommended). When I repotted in January, I mixed in some citrus fertilizer. I had to repot because 1) they needed bigger pots and 2) they had some small gnat or fruit fly infestation. They still have this fly infestation. I keep killing them, but they don’t go away. Fortunately, it doesn’t that they’re harming the plants. The plants have always been in pots with drainage holes. However, I suspect that the soil is absorbing too much water and not draining enough. I never see water draining to the bottom, but the soil always feels moist and very tightly packed, even a few days after watering. I water the three plants three times a week with one cup of water total each time. They get 9 hours of light a day with the grow lamp. I noticed that lately, some of the leaves have become pale and are starting to dry out. I’ve attached some pictures. Would you happen to know what causes this and how I can prevent it? Thanks so much. I really appreciate any help that you’d be able to offer!
Certified GKH Gardening Expert
I suspect they are getting too much water, which also accounts for the fungus gnats that thrive in moist soil. To help your soil drain, you can add about 1/3 perlite to the 2/3 cactus mix. Those browning tips can be caused by low humidity, overfertilization or too little water. If the roots are damaged by too much water, they may not be able to uptake water and show symptoms of underwatering.
Try cutting back the watering to once a week. Here are more tips for growing citron:
https://www.gardeningknowhow.com/edible/fruits/etrog/growing-etrog-citron-trees.htm
https://www.gardeningknowhow.com/plant-problems/pests/insects/fungus-gnats.htm
