why are leaves turning yellow then brown and falling off

Question

I've had indoor plants for years with no difficulties. Now several of my plants are losing leaves. This has been happening for a few months. The leaves turn yellow then brown and fall off. They are not limp and there are no obvious insects or their marks.

Answer 1

If all the plants are doing the same thing then you have to go to the lawn & garden store and get sevin..............take the plants outside............mix up enough liquid for a 5 gallon bucket.  If the plants are over the size of the bucket dip the tops first and then sink the whole plant into the container and wait until the bubbles top..........then take it out and let it drain................after that mix up 1/2 vinegar in a spray container and spray and wipe where the plants were located.  You also can make up a small container of Sevin spray to keep away from children in a safe place to spray them again in 3 weeks.  I would do this outside and keep it away from pets & children.