I've already cut mine back - to the base. It's not pruning, as the top growth does die off and new shoots appear in the spring. They're herbaceous plants. I always mulch them with compost a bit later on, to boost their growth for next year.

Phlox ground cover- perennials.

I planted quite a few of these last Autumn...15 I think. They have grown quite successfully and look quite healthy...BUT have not flowered this year. Is this unusual....or would you expect that in the first year? They have a very healthy looking amount of growth but are now starting to die back...: without flowering!-((((

Oooops!....This should have been a new question! Don't know what happened!

Sorry!

What sort of phlox are they, Izzy??

I cut mine down to about six inches from the ground to tidy them up and in the spring I just pull the dead storks out.

Izzy yours will probably flower next year,! mine dont get any special treatment and always manage to flower.