Attempting to save our avocados

I spent the morning clearing the bottoms of three avocado trees. I have several more trees to get to, but today, I tended to three. I removed all the weeds around the roots and added some lime and rich organic compost in hopes of boosting the chances of improving their health. A couple of weeks ago, Kevin pruned the trees and he noticed they were diseased. Insects were eating the leaves. We were told the only way to get rid of the insects is to spray chemicals on the trees. I'm bound and determined not to use chemicals. So, on the advice of another friend, adding lime will help the PH levels of our very acidic soil and feeding the trees with good, nutritious compost, they should build a stronger immunity against these pests that are attacking them. We can only hope! Seeing results will take about a year, but we were going to get rid of all the trees anyway, so we've got nothing to lose. I can't wait to report back with the good news that our trees are producing lovely, delicious organic avocados. Wouldn't that be awesome!