I've had a nice bed of Chrysanthemum Pacificum for about three years now and I've kept it trimmed down and tidy and it's always looked great. This spring it did fine, but now this Summer the older plants are just getting a bit thin at the bottom, the plants are opening up a bit, and the stems sort of woody.

My cuttings and the new plants from runners look great.

What's the best way to rejeuvenate a bed of this great ground cover?

Should I just rip out the older plants and let the newer ones fill in?

After it blooms in the fall should I just do a MAJOR cut back, maybe even mow the bed down so it will make new growth?

Any Suggestions?