Rose bushes

If there is dead wood on the roses, trim that off and then you can cut back drastically if there are signs of disease. They will come back when the rains and warmer come. You can cut back at least half way. Spring is also the best time after the buds start so that you can cut back to a node.

Here are some great links!

https://www.heirloomroses.com/info/care/how-to/pruning/

http://www.howtogarden.ie/pruning-roses-the-how-to-when-to-why-prune/

https://www.bhg.com/gardening/flowers/roses/tips-for-pruning-roses/

I prune mine in late winter, and deadhead throughout the growing season. They grow and bloom like mad!

rose bushes should only be pruned when dormant

Neighbors trim theirs every January. They cut them back to only a few feet tall.

They say Fall, but roses can be cut back in Spring too. 18" is what I've read, but ALL of the dead needs to come out. If you aren't sure which is really dead wait until you can tell. The good ones will start turning green in places & get buds and the truly dead ones won't. I have cut mine to 12" before and they are fine. Lots of info on internet. I like the articles from the universities best.

roses should be cut back beginning in january if you are in california.

Feb is when you're supposed to trim them.