[header] How to prune rosa rugosa [title] Know when to prune. [step] Most pruning should be done once the plant enters its dormant season. This can be any point in time between late autumn and early spring. 
[substeps] The best time to prune is in the early spring, after the danger of frost has passed. Pruning makes a plant vulnerable, and vulnerable plants tend to be weaker against the cold frosts of winter.