I’ve got a escallonia that I am trying to develop into a bonsai and two large landscape ones growing in my garden. They can make great bonsai, looking on the web both Tony Tickle and Bonsai Eejit have got some awesome ones. But there is very little out their in the way of species guides. However the great thing about the way Ryan teaches is the common horticulture base and thinking Bonsai/ Tree.
What I’ve learnt so far about this tree:
It’s hardy, the one I bought was frozen to the bench at the nursery and the entire rootball was frozen hard,
I repotted in in late winter with a significant root ball reduction to get it into a smaller container and did a hard prune at the same time. It sulked for a month and then started to recover well.
Even though it’s evergreen don’t worry if it loses a lot of it’s leaves over winter, it’s normal
Mines doing fine in a soil mix of 80% diatomaceous earth (cat litter) 20% pine bark
Normally you should hard prune after flowering in summer
Get movement wired in on soft young growth as the branches can become very brittle
It seems to backbud on relatively old wood.
You’re tree is looking good with movement being wired in. I think it probably just needs to grow and thicken. I think I would look at fertilising fairly heavily according to Ryan’s recommendations in the fertiliser video.