i have some very mature and productive avocado and citrus trees in the san gabriel valley. our soil is sandy and drains well. i just had an irrigation system installed and was unpleasantly surprised to see the placement of bubblers for the trees--in some cases about 8 inches from the trunks. i don't think that's how you do it with 50 year old trees. also, some of the trenching was done parallel with and inside of the drop line, a few feet from the trunks of these massive trres. (imagine digging a semi circle a few feet away from the trunk of the tree, and severing the shallow roots of the avocado.) anyway, it's too late to change that amount of damage to the roots, but should i have the sprinkler heads moved? are bubblers even appropriate for mature trees? I have been told to keep water well away from avocado trunks, and that avocados have wide shallow roots systems. interestingly, Sunset says to water frequently and shallowly--not typical for trees. help!