Here is the photo I posted of the catmint one month ago.
And here it is one month later.
It has easily tripled in size, and that is without any "special" fertilizer; ie, Miracle Grow. I don't think I've fed these plants at all yet!
Not only are they growing fast, but the catmint I planted last Fall is spreading babies all over the perennial garden!
Look at all those cute little babies.
These offshoots are from seed, so if you don't want your catmint to spread, just keep it deadheaded, or pluck the little babies out of the soil before they get too big. I personally like the extra plants!