I've been wondering about the timing on dividing grass and other perennials. All the books & articles say things like "early spring," or "late spring," or similar, but that's not very specific. I'm aware if it's done too early they might get frostbitten and roots can die if the temperature drops, but if done too late, they won't have time to start growing and blooming for this season. To further complicate matters, we had a freakishly warm March this year which caused things to burst out and start growing early. Then we had cold temps again. So for instance, I'm concerned that my catmint may have grown too high to be divided without doing damage, but not sure if it's still too cold to do so. It's currently at about 6"-8" tall.
Is there any sort of size rule? Will hardy perennials and grasses survive dips in temperature if divided? I'd love to hear anyone else's tips on this, especially those in Zones 5&6...thank you!
I live in southeast Pennsylvania, Zone 5 or 6. My neighbor has a beautiful garden, professionally installed and maintained. I had never cut my Miscanthus back before, but this year, when I noticed that my neighborís grass had just been cut back to ground level, I decided to cut mine back. I think it was in mid-April. Now (the end of May) my grasses look great. I suggest you drive around and see what other people are doing. Thatís what Iím doing from now on. I could go to a local nursery or arboretum, but driving around the neighborhood is easier (and free.)