I have some perennials that seem to be blooming very early, like my cone flowers and windflowers, which in the past, have been late summer. Will they give it another go later in the season, or is my garden way out of sync for the year?
I made the same observation a while ago. If you have plants that are budding now, most likely you can cut them back and delay bloom by weeks or more. The author of the "Well Tended Garden" explains in great detail how to do it for many different plants. If you don't own it, go to good bookstore when it is 90 today, and buy it. Then stay where it is air conditioned and read it. It really is invaluable
I'm not going to cut back the the first bloom of cone flowers, but I have pinched Autumn Joy back by a half, the phlox by a third, I hacked back a spirea I didn't get to before by half. That was two weeks ago and is completely covered with buds.
You can cut back Joe Pye Weed by at least a third, all the helianthus, heleniums, almost anything with multiple branching stems. Really, get out the hedge clippers or use your thumb and forefinger and pinch away.
Don't pinch back plants like veronicastrum candlelabra types. They'll grow back with multiple stems and lose their "real shape"
hWhat else? Any mums and keep pinching till early July, boltonias, asters, monarda.
Don't worry they won't all bloom at the same time. Different plants grow at different rates, so you'll still have a distribution of blooms over time.
If this makes you nervous, just pick a few to cut back.
Another interesting experiment is if you have multiples pinch back some alot, some less, and some not at all. You'll not only have a succession of color and bloom times for the same plant but you'll learn about the plants' growth habits.
Another suggestion: get some annuals that come into their glory in late summer and fall: all those wonderful salvias, which are at their best in the fall. Not the little squatty ones, but Black and Blue, the tall scarlets- a hundred choices. You may not have an excuse to buy annuals like these again in the near future