2lips Carol Ann,
Congratulations for the honor of being asked to be on a garden tour, I am certain your garden is worthy. Breathe in and out. With that said I am going to throw you a curve ball and suggest that your main focus not be on pruning/pinching plants for later bloom but rather to fully embrace the late season garden. Frankly I believe people are more interested in what they can replicate in their gardens and are not expecting the over the top flower show of a June or July garden at that time of year. Consider how lucky you are to have mature sized rare annuals and tender perennials at their best in the late season. Frankly I would consider plants with strong architectural foliage such as cardoon (perennial), Melianthus major (Tender Perennial?), Angelica archangelica or giga, ect.
If you are planting perennials now for the tour choose them for their foliar color not an ify floral display .
I would definitely not pass up filling up your garden with tender SalviaÂs, Ageratum (the tall one 30-36").
I think coming off a year from a wide spread tomato blight I would think twice about depending heavily on Dahlias.
I am on the news letter mailing list for Ken Druse who is NJ and doing a garden tour himself this year (Carl are you going) and he made mention of a 2002 NYT article he wrote about garden tours that I thought you might enjoy (or find useful).
Best of luck Katy

Here is a link that might be useful: Snippers, Snackers and Garden-Tour Gaffes By KEN DRUSE Published: June 13, 2002

If you have hydrangea Endless Summer (or 'David Ramsey', which is the same, only unpatented) in your garden and will deadhead it not later than July 10-15, you'll have a second flash by early September.
Also, depends on a cultivars, some lacecap hydrangeas (if NOT deadheaded) may produce nice show with inverted red petals. Lady in Red is particularly attractive in this respect.
...and September is the prime time for the most of H.paniculata :-))
Good luck!

Are you showing on the Garden Conservancy Tour? I know it's in September in this area; probably because parking here is impossible for non-residents until after Labor Day.

My suggestions: asters, mums, for Fall flowers, then garden ornaments & furniture to be visual interest.

Carol

Thank you so much for the fantastic suggestions! I have made a little shopping list (for special annuals & tender perennials, ageratum, asters which I don't have any of, plus mums, etc), jotted down July 10th in my calendar for hydrangea pruning, and thought about borrowing a few cute chairs, etc from friends! Also got a kick out of the article :-) I really appreciate the input!!

late September here, Sedum 'Autumn Joy' is usually in full bloom....as well as the last of the New England and New York Asters and the goldenrods...for annuals, try adding lots of sweet alyssum, that keeps going right until frost here. I think somebody else mentioned the blue salvia, those are great too for late season color. Oh and don't forget grasses - their plumes are usually at peak in the fall...good luck!

I just looked back at my photos from the last few years.

End of September blooms in my garden:

Shrubs/Trees:
Caryopteris, Lespedeza, Crape myrtle, Heptacodium miconiodes (red calyces), Franklinia, Callicarpa (berries), Daphne ÂSummer IceÂ

Perennials:
Boltonia, Agastache ÂPurple HazeÂ, Gaura, Ceratostigma plumbaginoides (true blue plumbago groundcover), Anemones, Persicaria ÂFiretailÂ, Chelone, Helianthus ÂLemon QueenÂ, Asters, Begonia grandis, Sedum, Knautia, Solidago, Coreopsis ÂRed shiftÂ, Eupatorium coelestinum, Eupatorium ÂChocolateÂ, Sanguisorba ÂLemon SplashÂ, Gentiana makinoi, Cimicifuga

Annuals:
Cleome ÂSenorita RosalitaÂ, Tithonia, Cannas, Dahlias, Salvia, Fuchsias, Thunbergia/black eyed susan vine, Verbena bonariensis

Vines:
Lonicera ÂAlabama CrimsonÂ

Bulbs:
Colchicum

In addition to the above good advice, here's my suggestion for you and for people planning garden weddings or other occasions where they absolutely have to have bloom on a precise date. My garden has also been on tours in the past so this is from experience.

Plan on hitting every nursery, big box store, whatever within a week or ten days of your target date. Have your design scheme firmly in mind and buy what is in bloom to fill in and brighten up. It's not the cheapest way to go but almost a necessity.

Even Gertrude Jekyll did this--not for tours--she was very private--but she did let the cognoscenti in and was prepared with her own home-grown supply of fill-ins.

Your problem is that it is so late so you might ask around now as to who will have plants in bloom for sale after Sept. 15. Good luck!

I'm not as organized as Monique (though I wish I were!) but I'll do my best with what I remember. Hydrangeas (Endless Summer & paniculatas), maybe some of my late summer clematis, Gentiana septemfida, Cimicifuga, my half-hardy sages like Salvia guaranitica 'Black & Blue' and pineapple sage, 'Lady Elsie May' rose, Dapne 'Summer Ice', geranium 'Jolly Bee', Colchicum & fall crocus, hardy mums, Montawk daisies. I also rely a lot on foliage all year, both color and texture. This far north some things are starting to color, especially in wetland areas by mid-September, but I don't imagine you can count on that.

There's a thread archived in the FAQ on the perennial forum on fall flowers which I've linked below.

Here is a link that might be useful: Some Little-Known Plants for Fall Gardens