We are having trouble with our smoke bush pretty much dying ever year. We have clay soil, which is very compacted. We have planted 2 smoke bushes, as they continue to die. We have a fire bush in the same area which is doing ok and are wondering why the smoke bush is having such difficulty surviving.
Smoke Bush does grow in most soil conditions, though if your clay soil is not well draining, this is likely the issue.
Smoke Bush prefers a full sun location though they can tolerate partial shade.
Make sure when you dig the planting hole that you dig it twice as wide as the root ball and you can add some organic compost to the bottom of the planting hole.
Make sure the tree sits slightly above the soil line. If planted to deeply the plant may suffer.
Make sure you are in the appropriate zone to grow Smoke Bush.
Most cultivators are hardy in zone 5 - 8, 'Royal purple' is listed as zone 4 hardy.