I have Nepeta Six Hills Giant...I always cut it back.- either fall or spring. I thought I was suppose to. I cut back my ground cover catmints too.

I cut back my caryopteris'.

I do that too to the old growth. BUT, how about the new growth so far this year? I have about 8 inches on each of my six hills, should I whack back now for a shrubbier look? Last year everything was so darn leggy.

I have the Walker's Low but it still gets pretty big. I don't usually cut it back until the end of June or mid July. By then it has spread into a 3-4 ft wide mound smothering everything planted near it.

Hmmmm..... Perovskia atriplicifolia is commonly called Russian Sage

Nepeta cataria is commonly called catmint. I have Six Hills Giant.

I believe they are different plants. Whenever I cut my Russian Sage, it smells kind of like cat urine. It will die back some, but does leaf out up the stem some 18" or more for me here in central Ohio.... so I usually just wait till it starts to leaf out, then trim back till I hit live tissue. It's sort of woody.

Catmint though, seems to come up each year from the base. I grow catmint Six Hills Giant on a large tomato cage, putting all the stems inside the wires till it reaches the top. As it grows then, it cascades out over the cage, creating a lavender waterfall appearance.

Jules

Yep, my RS got cut back and looks fine - but that was old stuff. Knocked that plant about 2/3. New growth looks fine.

I whacked the new growth on my Nepeta this week. Seems like it was the right thing to do. Another term for this technique is "pinching." I'm thinking this is what the doctor ordered.

Jules, I love the cage idea! I have a peony cage that I was using to protect a bottlebrush buckeye. It's big enough to hold its own, so perhaps that might work on my bigger nepeta mounds.