Plants are unpredictable. Even if the Internet and three reference books agree, they might bloom at unpredictable times, stay much smaller than expected, or spread. Take the Salvia cacaliifolia, (Guatemalan vine sage), one of my pre-native plant purchases. I received five 4 inch pots a few years ago. The plants grew respectably the first summer, but the winter after, a killing frost. I removed all the dead stuff, and they came back next year. Since then, when winter were cold, I just had to snip off the dead stuff. But when winters are mild, I have to remember my gardening teachers advice: "You are the fire, you are the deer, you are the frost."
When plants get out of hand, it's up to us to bring them down to size.
Last weekend, Salvia c. looked ready for me. I got out my trusty pruners and set to work. It's kind of fun not having to worry about the aesthetics of the work. Just snip snip snip, maybe a few pulls on roots that have spread too far.
There. That's better. Look at those hellebores and the Douglas iris on the right and left! And fortunately, even though the compost is full of leaves, we have garden waste pickup on Christmas Eve.
Perfect timing! And very satisfying to know that doing the work of fire, deer, and frost will keep the garden looking appealing and plants healthier.