How many gallons of water per week per tree?

fire...this condition sounds like what is quite common to most trees. Avos do shed leaves and small branches...and they dry up and turn black. As long as you are watering periodically you should be fine. Avos are shallow rooted. So, unlike most other trees...they do need more frequent water. I always try to water a couple of days ahead of a heat wave, also. You will be fine...

Not sure Tim. The avocado is on the edge of a lawn and picks up residual water from there, every two days as of right now. It has gone six years since I've purchased the house getting watered this way. The rest of the trees, 1-3 year olds get 4 gallons a week under heavy mulch with the hottest weeks getting a supplement mid week of a couple gallons. They can droop during the hottest part of the day but perk up in the morning.

Thanks Fireduck. I hope it is just sun scald however it didn't seem right to me.