|City Beach foreshore (click to enlarge)|
Big grass-free circle
This one is very big at 1.6m…1.2m or even 1m would suffice. The important thing is that the water (imagine it being watered by tanker) gets applied over an area slightly bigger than the rootball. This is important in sand as the water tends to go straight down. If you're only applying water close to the trunk you run the risk of not wetting the ground beyond the rootball. And that means roots won't be encouraged to venture out of the rootball.
Tree planted slightly lower than existing grade
Not a lot - perhaps 100mm - but even that depth over the area of the circle allows the water truck operator to put a fair bit of water on quite quickly.
It goes without saying how important this is in Perth's sand / heat. Without it, the ground will be dry again within an hour of watering. I like the coarse pine bark mulch they've used too. It stays porous and doesn't "cake" like some mulches can, inhibiting water penetration.
They've used three stakes here because of the coastal location. Two is enough everywhere else, just angled out a bit. But I do like the tie configuration: separate ties pulling in opposing directions. This keeps the tree very secure but still allows that all important movement of the trunk to initiate the tree's natural trunk strengthening process. Many Councils allow far too much movement of the tree. It needs only be subtle to be effective.
By that I mean the ring separating the grass from the mulch. These ones are galvanised steel and not practical for Councils planting hundreds (thousands) of trees a year as they would be too expensive and too heavy to handle. I'm currently liaising with suppliers with a view to trialling the same thing in a tough, rigid, HDPE plastic. More about that soon…
Me: Firstly, explain to them why it's necessary. Most people are fine once they understand. Secondly, if you do it very neatly like this there shouldn't be a problem. I would suggest it can actually enhance the look of their property.