What roses are at greatest risk?
1. Roses that are near and especially down wind of masses of multiflora or other wild roses, especially long hedges.
2. Roses grown on hill tops.
3. Tall and big roses, especially those on structures.
4. Roses that grow where canes from one rose are close to canes of other roses.
5. Roses downwind of windbreak type structures.
6. Roses in large rose gardens which are fertilized and watered regularly.
7. Roses grown east of the Rocky Mountains.
8. Roses grown by folks who don't know about rose rosette.
Our roses fit the first seven categories. We have redesigned our garden so as to increase distance between roses, decrease the number of overlapping canes, and increase airflow near as many roses as possible. We have built additional beds and taken up some old beds.
Early work reported some roses as more susceptible than others. From what we have seen in the last years, almost all ornamental roses are susceptible. Conditions where the mites are dropped from puffs of wind favor infection as do large areas of roses and rose gardens by simply increasing the odds of a mite landing on a rose.