Yes, in the front yard beds with the 5 Walker's Low catmints I will prune them down in bloom if they get too messy looking. They have nice attractive colored foliage that looks good against the thick blue green foliage of the sedums and contrast nicely with the strappy green foliage of the small daylilies in this bed. The bed is edged on one side in boxwoods, so although it is a curved 3 quarter circle bed it is fairly formal. In the more cottage-like daylily beds in the backyard, I prune when I can squeeze into the beds and/or without getting stains all over my clothes from the dls & hardy lilies in the beds. I wasn't kidding about the squashed catmints! These beds are really full, starting with bulbs in the spring, yarrows, knautia, crocosmias, gauras etc, in summer and mums & asters in the fall. Pruning is actually a ballet dance, bouncing around on one foot with sheers in hand.

Interesting. I have what I acquired as Walkers Low, which I see is listed everywhere as sterile. But though it looks and acts like every Walkers Low I have seen (obviously it is a common plant), mine seeds every year. So obviously either this is not Walkers Low or else mine has reverted (which still means it is not Walkers Low). In any case, I am delighted, because I have tons for my own garden, where it is a terrific groundcover, lots to give away (it transplants easily) and it is very easy to identify in the Spring and weeds very easily. Another two plants that seed for me that I did not expect are Jack Frost Brunnera and Hamln Pennisetum grass. Anyway, on the question, with mine I wait until the plant starts looking a bit ratty...spent flowers, sprawling habit, and so on. Actually, the plant itself generally tells me it is ready because as it sprawls one can seen the fresh new growth in the centre. Then I grab handfuls of the loose old growth and cut it all back. This leaves a small clump that quickly fills in. One can do the same thing with lots of different perennials (e.g., Pulmonaria (lungwort), Alchemilla (Lady's Mantle), Penstemon, some hardy geraniums, etc.).

I have quite a lot of Nepeta racemosa Superba (also namend N faassenii), mostly Superba, some "Grog"-cultivar, some seedlings. Lots of cats around, atl least 5 completely different looking ones all Nepeta are fine a neighbour grows a much taller type of Nepeta, perhaps something like Walkers low, also fine. a catalogue of a very nice German nursery lists a cultivar named Odeur citron which translates to: citrus-scented" and which is supposed to put off kittys... IMO well behaved cranesbill like Geranium himalayense Gravetye or Rosemoore (?all "o"s in the right place?) work well with bulbs. THey are quite good edging plants IMO, and have more oomph or ellbow than some of the lower Coreopsis.

I had to beg mine out of the ground. They don't even have buds yet. However, when I bought them the end of August last year, they had flowers till frost time.