Hieronymous
Rising Star
It looks like it could work. I'd be tempted to drill a series of holes around the lower part of the tube to allow a bit more air exchange. If the bottom few inches of the tube are filled with rubble then that should prevent it from becoming anaerobic.
You might need to find some way to give some extra support especially when the trees get a bit bigger. I imagine they'd blow over in strong wind.
Is the potting mix a low phosphate mix suitable for Australian native plants ? I would advise you not to use regular or even premium potting mix because of phosphate levels.
I've found acuminata to be only mildly phosphate tolerant. I potted up a batch of acuminata seedlings last year when I didn't have much native potting mix on hand, so I mixed the native mix I had with about 50% standard potting mix and most of the seedlings died. So be careful with standard potting mix, it just has too much phosphorus for many Australian Acacias.
As a general rule with Acacias, the drier and more arid their natural growing zone is the more phosphorus sensitive they tend to be. Many Acacias endemic to coastal zones that typically see more annual rainfall can tolerate much more phosphorus but it's always wise to play it safe and keep the phosphates to the bare minimum.
You might need to find some way to give some extra support especially when the trees get a bit bigger. I imagine they'd blow over in strong wind.
Is the potting mix a low phosphate mix suitable for Australian native plants ? I would advise you not to use regular or even premium potting mix because of phosphate levels.
I've found acuminata to be only mildly phosphate tolerant. I potted up a batch of acuminata seedlings last year when I didn't have much native potting mix on hand, so I mixed the native mix I had with about 50% standard potting mix and most of the seedlings died. So be careful with standard potting mix, it just has too much phosphorus for many Australian Acacias.
As a general rule with Acacias, the drier and more arid their natural growing zone is the more phosphorus sensitive they tend to be. Many Acacias endemic to coastal zones that typically see more annual rainfall can tolerate much more phosphorus but it's always wise to play it safe and keep the phosphates to the bare minimum.