I have a 3yr old plant that is huge, and taking over the corner of the garden. Once the flowers drop off, how much can I trim this back? Additionally,the same is true for my Russian Sage, should this be trimmed all the way down? Is Salvia splittable? They are getting big and starting to fall over. I will take any advice.
Thanks

It is best to trim both your Nippon Daisy and Russian Sage in early spring. Because Russian Sage has a woody base, you should only cut it back to about 12" or just below the lowest bud. I usually end up cutting mine back twice...once in spring and again in late summer if it starts to peter out. The woody base makes division difficult and not recommended. Mature plants often produce offsets that you can dig up and replant, but it's best to take stem cuttings to propogate.

Thanks, will take a closer look for those buds. You said to trim below the bud? What is involved with propagation?

Take a stem cutting about 3-4 inches long from a non-flowering stem...remove the lower leaves...dip it into rooting hormone...put it into potting medium...place in lighted area and keep moist (you can cover it with clear plastic to hold in moisture, check it often and water as needed). In about 6 weeks or so the roots should be growing.