I'm interested in your experience with top dressings.
I've read about how moss can be difficult in our climate and solutions for making it work in the Parameters for growing moss chat. I don't think I'm ready to mess with that, yet.
Still, I am having issues with soil washing away when I water – particularly on store-bought, deciduous trees that have more of a traditional soil, instead of the akadama mix I've used on others. So, I'm looking for ways to cut that out.
I have one tree from The Bonsai Nursery with a kind of sharp, small, black rock on top. I can't tell if it's lava or not, but it seems to work really well without the bulk of chunkier lava I've seen around.
Perhaps the solution is going back and asking what they use, but I'd still like to know more.
What do you use?
Other things that will help: 1. A really fine watering watering spout.
2. Control while you're watering to avoid flooding.
3. Leaving a "ditch" around the the outside of your pot, slightly below the rim of the pot. This allows a little movement, without the soil washing out.
4. If you fertilize with anything that contains or is humic acid, the soil particles eventually stick together pretty well.(on my trees) This shouldn't be confused with soil going hydrophobic!
5. You can use window screen on the top of the soil, and this can also help prevent washouts.
-Spaghnum technique doesn't work in my yard very often.-