This tree is planted in Houston, TX (several years, no fruit) and now has small green lemons growing on almost every branch but there are tiny yellow ones falling off. What is causing this? I got my first full grown lemon that fell off the bottom this week and is delicious but will the other nickel, quarter size green ones grow? Over the years they never have fully developed until that one the other day. Some leaves are "curling" and die, is that a fungus?