If you chop the spent head off, avoiding it spending all it's time on making seeds, you may get some reflowering in a month or two?

Well, mine has been somewhat like yours (4-6 weeks of bloom, then a few small flushes till fall). There's almost nothing that's a reliable perennial that can bloom it's head off for 4 months. That it flowers till fall, is that it may have a couple of flowers open till fall :)

OK, that's good to know. I got particularly thrown off by this article from The Spruce that claims "...it helps you keep your yard colorful in the second half of the summer, after the flowers of many other plants have gone by. A long-blooming perennial, once it comes into flower, you can be assured of color in the yard until the frosts of fall arrive."

Until the frosts of fall arrive? Really?

I see you're up North, where the frosts of fall arrive much earlier (lol), but you gotta remember England is a much more temperate climate than mine at least, and probably even yours.

One thing I noticed when I have been in Canada in late summer and early fall, is their plantings always look so much fresher than ours in the South that have been tormented by hot dry summer.

It's all relative depending on climate, I just have to console myself that they can't have cannas or maybe even dahlias because of the colder shorter seasons, and certainly not the southern hibiscus or amaryllids. So..it's all a trade off. Other than asters and physostegia, and a few sunflower species, I usually turn to fall bulbs for surprises in the late fall. For sure, no long blooming perennial is still blooming by then for me.

Thanks, gardengal. I hadn't known that new plantings may not bloom as long as those more well-established. That's good to know. And we certainly have been having some serious heat, and especially humidity, here in Boston. It would be interesting to learn more about how periods of exceedingly high humidity affects garden flowers. We've been getting some good rain so the soil doesn't seem dry.

OK, so when a website says "July-Sept" that could be referring to the total of the period of primary bloom as well as the smaller secondary bloom.

Garden phlox cultivars differ notably in things like colour and height but also on when they routinely come into bloom.

We currently have several dozen different garden phlox cultivars, usually with more than one plant of the same cultivar. Location within our garden is certainly a major influence on when plants of a particular cultivar come into bloom (notably how sunny the particular location is).

Still as said there are some systematic differences in bloom time between cultivars. I could not rank our cultivars by bloom time, but occasionally earlier versus later-bloom time seems quite evident. 'Glamour Girl' (in a number of locations in our garden) comes into bloom after most of our other cultivars. Again, in all of this, "which and when" is complicated by location.

Our garden phlox which blooms the latest is certainly 'Nora Leigh' (relatively nondescript bloom but variegated foliage). The foliage of many of these plants still looks fine here in October. I've been thinking that the strong mildew resistance of this cultivar might be related to it's late bloom time.

I'd say that the way to have garden phlox in bloom for a long time includes having many different cultivars and healthy plants in good growing conditions.

Thanks, dbarron. btw, I'm not sure I understand your reference to England -- is the Spruce published there?

That's what I thought..I could be wrong ;)

Hmm, I wonder what site I was thinking of...seems Spruce you referred to is indeed American.

I just noticed that I did transcribe the plant label into my notes when I planted it, and it says "Bloom: June to August." OK, that explains it.......

I have found that The Spruce isn’t a particularly reliable source for particular plant info. I am another fan of MOBOT for accurate info on a huge range of plants, though I often have to consider that both their pH and temperature are much higher than mine and adjust accordingly. Other sources that have comparison tests between different cultivars within a genus include the Mt. Cuba Center and the Chicago Botanic Garden. If you want info on a specific group of plants such as Rhododendrons or conifers, both the American Rhododendron Society and the Amaerican Conifer Society have incredible databases.

The reliability of MoBot has grown on me.

If their handling of Primula veris (both classification and name) is representative of the work of the Catalogue of Life, I'd put much greater faith in the Plant List (Kew, MoBot, etc.).

http://www.theplantlist.org

New on me recently too, Rick.