AusBonsai

Hey all,
I’ve finally given a slab a go using a fig. I used a piece of rock from around Brisbane/ipswich area, so maybe a granite or something. The problem being that I couldn’t drill any drainage or anchor points in it.

Sorry for the photo qualities: Essentially the tree is sitting on the slab with just the soil to keep it in place. I did make a few holes through the bottom of the muck with the intention of allowing for drainage.

The muck was made without much difficulty, but I used a mixture of dried out and crushed sphagnum moss and normal moss from around the garden to go over the surface. I couldn’t get it to stick very well to the sides, even when wet so had to use this coir rope to secure it.

In the end it seems to have worked out ok, but some of the leaves have dropped off, which I’m assuming is from the transplant. I’m wondering if anyone can tell me what problems I’m likely to encounter and what best practice is for something like this.

Thank you

First problem is that rock slabs dry out really fast. Not only water evaporating from the surface and what the tree is transpiring but water also soaks into the rock and evaporates from the exposed edges and even from below. I always had problems keeping trees on slabs alive due to drying out so much quicker than pots.
You've chosen well. Ficus can tolerate dry much better than most other species so it should cope.
I would not worry about lack of drainage holes. Unless it is a torrential downpour excess water should filter through the soil and escape.

The other problem is usually erosion of the muck walls. Hopefully your moss will hold it together. Keep some muck in reserve in case some areas do start to wash away.

Thanks mate, as always.
Great to build up the knowledge without killing too many trees.