Q.How to remedy lemons not growing to full size and rotting from inside
Our lemon tree is old – some of the fruit has a rough/brownish skin and does not grow to full size and some have brown rotting inside. Is there treatment for it?
This is called citrus brown rot, and is fast-spreading. It can be quite a problem to tackle but there are treatments. Here is an article that will help: https://www.gardeningknowhow.com/edible/fruits/citrus/citrus-fruit-brown-rot.htm