I think some hollyhocks are perennial, and should probably be left undisturbed or cut back. If they are done blooming and biennial I would go ahead and rip them out.

I think sometimes it's hard to separate the new plants from the old so ripping them out can be problematic.

Hi ProudGM,
If you have problems with Hollyhock rust then dig them up and out they go into the trash, don't add them to the compost heap. I've been able to control most leaf problems with the use of a systemic rose treatment which controls rust, leaf spot and powdery mildew. I use a product made by Bayer--you just toss a cap down onto the ground under the plant and scratch it in. If you can find a different brand that appeals to you it will be the same effect--where I am I think Bayer is the only one that I can find which does the work quick, easy and efficiently.

T

I don't have a problem with rust. I just thought that they were all biennial and once they bloomed they were done. I have no idea if mine were biennial or perennial but I know that all of them that I had bloomed this year (2nd year plants) so now I don't know whether to yank them out to plant new ones or not.

See what is alive in the spring. Hollyhocks reseed and you likely have some started already. I have had some come back after blooming. They don't need to be very big in the spring to bloom. I left some 6" plants in my vegetable garden thinking they would bloom next year. No, this year they grew to 6' and shaded out most of my carrots.