I haven't heard to pinch three times--that's news to me. I pinch mine around mid-June or about the time they've grown to 2 ft. in height. I just pinch the first pair of leaves on each stem. This has worked to control height & flopping so far but only one clump is mature enough (3+ years growing) to maybe need a second pinch. Glad you asked this question--I'll be interested in seeing what others have to say.

according to 'The well tended perennial garden', she indicates to 'cut back by 1/2 in early-mid June, which which would delay flowering by 2 weeks. if cut back earlier in mid may, flowering may not be as greatly delayed...' She goes on to list specific varieties ending up 6" to 12" shorter doing this.

Wonder if you could cut back now and then again mid June for the look you want?

I have flox that grow 4-5 feet tall and we would like to keep the height lower if that's possible. Just cutting top 1/2" will make it 6"-12" shorter? I will try it on half of the lot this year. Any more details (with photos etc) on this technique? (I will post links if google helps me out ..)

tnker

I think you misunderstood what linda0210 said. She was quoting from the book, The Well-Tended Perennial Garden, and the statement was as follows: Cut back by 1/2. That means cut the plant in half (not a half inch!) What I usually do is cut the first bunch of leaves off the plant in Mid May (now) and the second bunch a month or so later. This pruning results in two branches being created from the one stem (i.e. - bushier with many more flowers!).
Sometimes I get two stems, but not always. I was trying to figure out how to ALWAYS get two stems. (Greedy bugger, aren't I?) Then when you cut the second time, the original stem is now four! Pretty cool, eh? Happy Gardening.

I once pinched it back in half mid-June and it never recovered and bloomed well, so I never tried again. Maybe I'll try it now in mid-May.

The precise answer probably depends on the particular cultivar and micro-climate. Experiment and take notes for next year.

Personally, I've never pinch any garden phlox, as I like massed phlox bloom coming at multiple heights.

Re bushier with more blooms: some old and some newer phlox (latter, e.g. 'Peppermint Twist') are so vigorous that my emphasis would be on fall division; namely, on avoiding too much of a good thing (or rather too much of some good things at the expense of others).

Can you bring in for winter. I have one that I took out of garden early after bloomed didn't look well. Put in pot and started blooming again.

Phlox need to be outside for the winter - they don't make good house plants. I'd either plant the whole pot and mulch well (planning next spring to plant it back in the garden) or plant it in the ground now and mulch well. Don't put mulch over the stems -put it around the plant.

Txt for info

I forgot to add that after a hard frost you should cut the plant back to the ground and clean up any fallen leaves. Phlox tend to get powdery mildew, and if you remove the year's plant debris in the fall, there are fewer disease spores left.