I was told since the avocado tree doesn't have much of a tap root sand would be okay and not to add soil or amendments to the sand which will slow down the drainage or cause fungus and lead to root rot? So maybe it would be a good idea to add perlite to the whole sand mix and not just the 2' diameter around the tree since I'm not pulling the sand out now?

They also told me not to fertilize for the first year since it could burn the roots and the potted trees contain enough fertilizer for the rest of the year.

All I can find in bulk is top soil which is to heavy, wood/compost which is mostly wood or manure/compost which I've read some articles say it's okay and some say stay away form manure for young avocado trees?

Here's some of the soils/compost I found on Facebook. The bottom right looks good but it's a 2.5 hour round trip and I need to make 3 trips since they don't deliver to me.

" I was told since the avocado tree doesn't have much of a tap root sand would be okay and not to add soil or amendments to the sand which will slow down the drainage or cause fungus and lead to root rot? "

Sorry to say but you have been grossly misinformed. Sand, especially fine grained sand like you show, does not offer fast drainage at all. There is inadequate pore space between the particles and that inhibits fast drainage. Root rots are far more likely to occur in a fine grained sand than they are in a coarsely textured standard soil mix. And the combination of sand and perlite is not a productive growing media in any sense of the word. Unless they are sand dune or beachside dwellers by nature, plants need - no, require - a mineral based soil to thrive.

It may be that you have included instructions for growing avocados in containers with that of growing them in the ground. The two conditions are vastly different and should not be confused or combined. A raised bed with no solid bottom is just the same as growing the tree in the ground. Avocados in the ground want a slightly acidic, loose, fertile and well drained soil. Sand and perlite are simply not a factor in this equation!!

Since this sounds like this is intended to be a permanent outdoor planting, I assume you are in California or Florida. Bulk soil providers are located all over the place in both areas and it should not be a big deal finding an appropriate mineral based soil to fill your bed.

NEVER amend a planting hole...

just about everyone of your presumptions are wrong ...

perlite is used in potting medium... it has a half life of about a million years.. and should never pollute mother earth ...

have you perc-ed your soil outside the planters... ??? ../ with trees its all about drainage .. and sand is not used to make drainage.. it has higher odds of making cement.. especially when it has clay in it..

https://duckduckgo.com/?q=perc+garden+soil&t=ffab&iar=videos&iax=videos&ia=videos

see if this helps.. and hold the plants until fall if you already missed your planting period .. which is section one,. there is also a section on amending soil..

https://sites.google.com/site/tnarboretum/Home/planting-a-tree-or-shrub

ken

From talking to several nurseries around here who have failed growing avocado they said avocados won't grow in my soil unless mounded up or in raised planter. The sand in the planter does have nutrients since it's not been washed and it drains great unless you mix in the native top soil then it turns to concrete, that's why I didn't want to mix soil into it. I have 6 yards of soil/potting coming next week to mix into the sand which they said the ph is around 5.8 and it does have some bark in it so I hope it still drains but this way it will give the soil more nutrients, structure/anchor and I wont have to water so often. Since there's no turning back now I will mix it with the sand 50/50% in the upper 2' and see how it goes and top it off with pine bark. Internet can be your friend or enemy depending on what you read. The nursery told me to stick to the Fl university web site which is good advise.

Picture is similar to the dirt/compost I have orders but with less leaves and twigs and little more bark.

I have no experience growing avocados, and I sure don't have any experience growing anything in Builders' sand, but it makes me sad to see all that hard work fail.

Avocados like a fairly rich soil. You have provided them the opposite---a nearly sterile medium. If I were going to invest any serious money in the trees, I'd start over. I'd pick up those planters and plop them down somewhere else and fill them with soil. The University of Florida website says to refill the holes with the native soil you took out, didn't it?

Also, compost doesn't burn roots. I'd put it on top, though, not mix it in my soil. Compost is temporary. It disappears. You don't want to mix it in soil and have the area sink in a few years and make that bowl situation.

You'd done such a nice job, I hope you won't proceed without doing more research, because that sand looks like a recipe for disaster to me.

Also, what's the spacing? I've been seeing 23' feet between the trees and buildings or other trees.

How did you end up plating your avocado trees? Did you use the sand after all or change your mix , and how are your trees doing today?

I mixed some topsoil, worm castings and perlite in the upper sand media.

With all the work I have and since the bugs, disease and critters are making it hard growing anything I have given up. I never planted anything in the planters, I figured better taking a lost now then waste anymore of my time.