Why a planter? And why bottomless?

Good question! I thought it will help since avocado tree seems very hard to grow I heard. So it will not be too wet from the lawn, it will get more sun, I can amend the soil (never amend my soil for my fruit trees and citrus trees, they are ok). Maybe I don't need to?

It's actually a great idea and should work wonderful. I have several raised beds that are "bottomless."

What to fill the raised bed will depend on your native soil. Avocados like well draining soil. If your native soil is clay, like mine, I would break it up with a pitchfork first, then add well draining soil and mulch to your raised bed. If your native soil is sandy loam or well draining soil, you probabaly wouldn't need to break it up with a pitchfork and could just add to it.

Personally, I would line the bottom of the raised bed with gopher wire, but that's because gophers are a real problem where I'm. I line all my raised beds with gopher wire here.

How deep and how big is up to your budget. :)

Thank you cori ann! I am at north California as well. What is well draining soil? Would cit work if I mix 50% into the native soil? What kind of avocado tree do you have? Would 3' wide planter big enough?

We are in really different areas so hopefully someone local can advise you on the soil. It really depends on a lot of variables and I couldn't advise you properly. If no one local to you chimes in... try asking a local trusted nursery and maybe bringing some of your native soil in a bag to show them.

If you search for 'well draining soil' you will learn a little.

I have two Mexicolas and one Bacon. I tried Hass but it didn't work here. I might try it again at a later date.

How deep are you planning your 3' raised bed to be?