Roses and wintercreeper are two where you will see this on them and not on surrounding shrubs of different kinds. I wouldn't expect it to sweep through your plantings, getting on everything.

Not that it doesn't have a broad enough host range to have been a problem in nursery production areas in Oregon.

I removed my row of small euonymous after it developed crown gall some 15 years ago. No other plants in the yard were affected. The only shrub that has been planted in the same location is a hebe, it is doing well.

Thanks so much for the replies, it's really encouraging to know that it won't necessarily spread to everything. Should I remove the wintercreeper and replant with something else? And are there plants that are resistant to this?