Other than a susceptibility to Verticillium wilt (as are many other plants), not much bothers the doublefile. Without a doubt one of the most striking shrubs when in flower!

Normally I would not suggest to prune to control width - that very wide, layered branching is one of their premier attributes. But the cultivar 'Summer Snowflake' tends to have a very upright, less spreading habit and can be much more easily kept to a narrower width. Also blooms sporadically throughout summer rather than in one big blast like more traditional cultivars.

Summer Snowflake looks very promising! Thanks for the suggestion.

May starve out if nutrient levels not kept up, many local examples have poor foliage color. I had an old 'Mariesii' deteriorate when the bed was not being kept mulched like in the past; fertilization produced a marked but temporary improvement - making it clear an onset of chronic infertility was the issue.

When I have seen it growing wild here - perhaps having spread from cultivation via birds - it was in a deciduous woodland on a river bench, where the soil would both have been fertilized by the river and by the fallen tree leaves.

My in-laws had a beautiful one in their backyard along a creek and under Douglas firs.

Do either of you know what the rate of growth is for these, especially Summer Snowflake?