Planting a Bloodgood for niwaki cultivation...suggestions/advice?

[Dennis]

I'm planting a Bloodgood to grow as niwaki; a trained small garden tree. It's 8 ft tall, has a 2.5 inch (60+ mm) trunk and is in a 15 gal. (60 l.) container. I would welcome suggestions on planting method to enhance niwaki development. I have very fine textured red soil, pH 7, with little organic matter. I'm particularly interested in:
1. Soil amendment to lower pH long term...how much and far out from the trunk? Peat or bagged amendment? Blood meal?
2. How do I treat the root ball if it's crowded; a few small roots are from the drain hole?
3. How can I cultivate large gnarly surface roots?

I don't plan to do any major shaping or pruning until next year but will do some light snipping to open it up after the leaves have dropped. The photo shows the tree today in its proposed location in dappled shade under an giant old juniper.

 

[0soyoung]

Generally, composted organics will help acidify the soil, but you can also use Ironite (iron sulfate) if you start having chlorosis problems. I suggest that you don't fret about amending soil because in short order roots will be growing beyond any area you are likely to prepare.

As with normal gardening practice, loosen the roots, especially those on the surface of the 'ball' and cut any that are circling around the pot.

When you plant make sure the root collar (where the roots first emerge from the trunk) is no lower than the surrounding soil level - upto 6 inches higher, unless you want to have your tree on a mound (which is a way to solve general gound drainage problems). Make a watering ring around the tree above the edge of the pot-ball.

The root ball of a 15 gallon pot should be heavy enough that it won't be necessary to stake the tree (as I recall it isn't ever terribly windy in Sedona, but the point of staking is just to keep the old root ball stable until roots have grown out into the surrounding soil). After a season or two you can begin pulling soil away from near the tree to progressively expose the nebari or big (maybe gnarly) roots near the trunk.

I do structural pruning shortly after leaf fall; shaping and thinning when in leaf.