A leaf drop per day on indoor citrus

Asked September 11, 2017, 6:38 AM EDT

I have indoor growing lemon and lime trees. Both in South facing windows with grow lights on each from 1am to 6am every morning before getting natural light. Both are 2-3 years old. Every morning I wake up to a fallen couple of leaves from each. The lemon has lost most of its lower leaves, but has about 15 small lemons growing on it. The lime tree has more leaf drop, but also is growing new leaves. It's small limes don't appear to be growing though. Most of fallen leaves on both are curled and yellowing. Some fungus gnats, but I control with been oil drench and yellow sticky paper. I water once every 8-9 days and Citratone fertilize once a month. How do I stop the leaf drop?

Baltimore Maryland

3 Responses

Leaf drop on citrus can be due to low light, plants are rootbound, changing water conditions, etc. any type of stress.

We recommend that you place your citrus trees under a grow light for 12 hours a day. They need bright light and light intensity is changing this time of year.
The plants may be root bound and we recommend repotting into the next size container. Do not plant annual flowers around the base as there is competition for moisture and nutrients. They are heavy feeders so continue to fertilize. Do not feed plants until the light intensity improves. While the plants are actively growing allow the top inch of the mixture to dry out between waterings.

Thank you. Have seen an increase in fungus gnats lately and was loosening up the soil around the plants to aid in drying it out faster. Came across these .75" larvae looking things. Aren't they too big to be fungus gnats larvae? If so, what are they and how do I kill them?

This does not look like fungus gnat larvae. This looks like it may be a type of caterpillar or beetle larvae. If the plants were outside, it is possible that is why they may be in the soil. If you would like more information, send us more photos of the larvae. Turn the larvae over and send us photos of the underneath of the body. We will be looking for legs/prolegs.

In any event, we recommend that you take the plants outside and repot. Make sure the container has holes for good drainage. If not, you may want to select another container. Knock the soil from around the roots and remove any larvae. You can use a mix of cactus and potting soil or a seed starting mix. You can use the same size container but you may need to trim some of the roots lightly. Be sure to place under a gro light for 12 hours a day.
Repot the annual plants in their own containers and care for them separately.

Here is some information from our website on fungus gnats. They like to breed in moist soils. Repotting may help with this. Allow the top inch of the mixture to dry out between waterings. http://extension.umd.edu/hgic/plants/fungus-gnats-houseplants