I've put tens of
trees in like this since and the most tedious part of this job is making the crater. Not just the time and effort to do it but the fact the truck engine is running for 20+ mins to power the drill is a negative.
The masonry drill I used when I started this
thread was 30cm long.
I've since switched to digging a much smaller crater and then a single hole with a 1 metre long masonry drill and putting in trees that are younger and smaller. I'm thinking that the roots will benefit more from going deeper than from having a bigger but shallower rootball and the power tool time is easily halved. Or put another way I can plant more than twice as many trees in the same amount of time. I'm hoping the trees that are able to send 1 metre
deep roots easily will outperform trees that were initially bigger but have to fight thru rock to get roots more than 30 cms down.
I've also started leaving the craters for a few days before planting. I notice that if I leave a crater, then a couple of days later it's full of rabbit droppings. Seems the
local rabbits like to crap in my holes. Ill take the free help!