Hahaha,
I don't! I just hope the will follow as much a downward path as possible. But I DID keep the roots against the roch whil adding sand on top of them, in an effort to have them follow the rochs' shape. Is just.. If there are no nutrients, I hope the plant will send roots down. On the way they should encounter the rock and follow it.
Hm. yeah, I love those pinchers. They are very strong, sharp. I rbought them from Rumania 2 years ago. Best buy ever.
I did not do any trimming, but naturally, when you have 3 trees in s small pot for years, the roots get clumpy. I did loose some roots. Trick here is to get long roots to start with; One of them did, the others did not have them.
Over the winter months every week I will scoop out some of the sand on the side, so the watering will naturally erode the sand away from the roots. By spring I hope to be able to lift it out of the ugly containers, and plant it on a tray. The idea is that the main soil will be under the rock, and it becomes a rock-outcrop on which trees grow. This also means: I want a few strong roots on the rock, but the rootball at the bottom: I needed as much root as possible.