Nepeta – Walkers Low is one such winning plant. The butterflies and bees love it as it continuously blooms over the summer. While it’s lower in size than the standard Nepeta, it can reach to 30 inches high. My one plant which is about two years old is now four feet wide and 15 inches high. I have taken the hedge trimmer to it to keep it’s size in check.It doesn’t seem to mind.