Ficus Benjamina Tree
i keep my tree outside during spring and summer bringing it in when nighttime temp drops. This year the tree is dropping new and old leaves from the stem, not turning brown or yellow. I do see on the branch a wispy looking dust like form on the branches. I sprayed the plant drenching it before bringing in to kill scale or mites. It was beautiful. it is in bright indirect light. it is growing new leaves, i water it once a week. it is so disheartening. can you help. my Jade plant is doing the same thing as well as my Schefflera. I did re-pot all plants this summer. They are not root bound. My Ficus is 12 years old. my Jade is 12 years old my Schefflera or umbrella plant is 15 years old. please help they are my pride and joys.
There are a number of issues here for your plants. One is adjustment to the change in light. A second is possible exposure to temps that were too cold. Third, the effects of unnecessary repotting may now be starting to show.
I know folks like to move their indoor plants outside in warm weather because they generally thrive outdoors. However, I do not usually recommend doing so because it forces a difficult adjustment for those plants twice every year. In nature, plants put down roots and stay put throughout their lives. It is quite unnatural and difficult to make a plant adjust to major changes in light.
Ficus trees are particularly sensitive to even small changes in light intensity. When moved indoors, Ficus trees should be located right in front of a very sunny window where they can get lots of DIRECT sunlight. Give your tree a vigorous shake weekly to help it shed older leaves that no longer getting enough light. Prune off any branches that have lost all their leaves or are dry and brittle. In fact, now is a good time to prune your Ficus back by about a third. Pruning will help trigger new growth as it removes older foliage that will gradually die back any way.
The “wispy looking dust” could be spider mites, but I cannot be sure what you are seeing. Ficus trees often have a slightly whitish film on their leaves and that is normal and does not require treatment. If you suspect spider mites, let me know and I will explain how to treat the mites.
Older plants should not be repotted. They do best when kept moderately root bound. Unnecessary repotting often damages fragile roots and the addition of ew soil means the soil does not dry out properly, causing root rot and eventual death. This is not an inevitable result of repotting, but it is a substantial risk. You now have to be very careful not to over water because the added soil retains water much longer and the reduced indoor light slows plant growth and the plants then use less water. Keep your plants as dry as possible now.
If nighttime temps fell below 55 degrees F. for your Schefflera, 45 for your Ficus or below 40 for your Jade that may be contributing to their problems.
Finally, your Jade and Schefflera should also be in direct indoor sunlight.
There are a lot of considerations here, but I am most concerned about the light and repotting.