This article originally appeared in the June/July 2002 issue of Growing for Market Magazine.

One of most important factors in a successful flower business is succession planting. It is simply not possible to plant once, then sit back and harvest for the rest of the season. You need to have new crops coming on all the time, and you need to always be looking ahead three or four months to ensure you’ll have a long, profitable season.

So although you may have just finished getting your summer flowers planted, it’s time now to start on fall crops. Summer’s heat, pests, and weeds will take their toll on your first few plantings, and by September, you’ll be longing for some fresh flowers to take to market.

Annuals are the key to fall crops in most parts of the country. Perennials may be useful, but there are few perennials that bloom in September and October in most of the U.S. Many of the so-called “fall perennials” such as Physostegia, Sedum and Solidago, bloom in August in climates where the weather is frost-free beginning in March or April. By the time September arrives, there are generally few perennials that haven’t bloomed.

The wise flower grower will plant as late as 90 days before the expected first frost - or even later, if the gambling type. Many years, frost will be several weeks later than the average, and it pays to have flowers to sell as long as possible.

“Some years we lose money spent on seeds because all the new plants get frozen,” said Joan Thorndike of LeMera Gardens in Ashland, Oregon. “But some years surprise us: the plants manage to bloom, albeit just one flush, before the hard frost hits. We find that last crop to be the icing on the cake for the season because every fresh flower that looks really fresh and beautiful in October is manna from Heaven.”

Joan is one of four growers I called from different areas of the United States to find out what they are planting now to cut in fall. Also contributing were Dave Dowling of Farmhouse Flowers in Maryland, Peggy Huff of Johnny’s Selected Seeds in Maine, and Tammy Ford of Perennial Favorites in Indiana. Their recommendations, combined with my own menu of fall bloomers, provides an extensive list of flowers you may be able to grow in your area:

Agrostemma - This is one of those varieties that Joan seeds late, after summer’s heat has broken, on the chance of a delayed first frost. The silky, speckled blooms of lilac or white require 90 to 100 days, and do best in cool weather.

Artemisia annua - Sweet Annie will bloom 90 days from planting, and the new organic variety from Johnny’s Selected Seeds blooms later than the others, says Peggy Huff, who is managing the flower trials at Johnny’s.

Asclepias ‘Silky’ series - I have planted these as late as mid-July and gotten good production from them until frost. The beautiful new red varieties, coupled with the Silky Gold, are great fall colors. Start them in the greenhouse now in small cells and get them out into the field asap. Our Maine and Indiana contributors also mentioned Asclepias as good for them.

Asters - Joan recommends the annual varieties, Callistephus chinensis, for a late crop. ‘Matsumoto’ blooms in 90 days.

Bachelor Buttons - A quick flower that works in cool northern areas such as Maine, but probably not in hot climates.

Bells of Ireland - They work for Joan in Oregon in fall; they take 90-110 days to bloom, and they like cool weather, so it will be tough to get blooms in most climates.

Calendula - Same as Bachelor Buttons. Try the bronzed variety ‘Indian Prince’ from Johnny’s for its great fall color.

Caryopteris incana - It’s a mystery to me why more seed companies don’t carry this, as it’s a great late-blooming cut flower. It’s the tender cousin of the woody shrub Caryopteris x clandonensis, Blue Spirea. The deep blue flowers (with a few pinks and whites) cover the 3-foot stems from September until frost. Park Seed has it, way in the back of the catalog, under a section called “Garden Treasures.”

Celosia - Everybody plants celosias of all kinds until mid-summer. Dave Dowling says he direct seeds ‘Chief’ because it loves the heat. I like the orange ‘Chief Persimmon’ for fall bouquets. Hi-Z is quick to bloom, and Amazon has great purple foliage.

Cerinthe major - Fleshy, bluish green leaves get a purplish cast near the top of the stem, where a small purple flower dangles. It’s an odd looking plant, in my opinion, but it can be used in mixed bouquets. I planted it in spring last year and it looked good until mid-June, when it fried in the heat. Peggy says it looks good in fall in Maine; the cooler temperatures intensify the purple color.

Cosmos - All cosmos bloom better in the cool, short days of fall. ‘Versailles’ is especially suited to fall, as it blooms under short days in 60-90 days.

Marigold - ‘Gold Coin’ is the cut flower variety that blooms in fall; in fact, it requires short days to flower. It needs 90 to 100 days to bloom.

Salvia - All of our contributors grow the blue annual salvias ‘Victoria’ or ‘Blue Bedder.’ They really thrive in the cool days of autumn, developing intense color.

Salvia leucantha is another good choice for growers in areas where first frost isn’t till mid or late October. This wonderful plant, known as Velvet Sage or Mexican Sage, has long stems of fuzzy purple flowers. It needs short days to bloom, so no matter when you plant it, it won’t bloom until the day length is right.

Here on the 39th parallel, that’s September 15. Unfortunately, it is extremely tender and the lightest frost will kill it. And at four-feet tall, it’s too tall to protect with row cover. We grow it in the unheated hoophouse and have flowers till late October. There are two varieties, one all-purple and one purple and white. The all-purple blooms two weeks earlier than the purple and white. “Last year I pinched some plants in early July with good results, nice long single stems, none of those bushy stems that need to have all the side shoots stripped when picking,” Dave said.

Saponaria - Another cool-weather filler that Joan in Oregon sometimes gets to bloom before frost.

Sunflowers - ‘Elite Sun’ is ready in eight weeks, ‘Sunbright Supreme’ in 10 weeks, says Dave Dowling. Joan grows ‘Sunbright Supreme’ in pots in the greenhouse for fall bloom. We use the hoophouse for the last crop. If you want to try other varieties, look for those marked “day length neutral” for fall crops.

Zinnia - Keep planting those zinnias. They grow really fast in the hot days of summer so we plant until August. Watch for powdery mildew in September as the nights get cool. We have had good luck with the baking soda cure for powdery mildew: Mix 1 Tablespoon baking soda and 2.5 Tablespoons Sunspray or other light horticultural oil per 1 gallon of water. Spray on plants every seven days, covering foliage thoroughly, including the undersides of leaves. This has kept the disease at bay until frost.

That’s it for the annuals (though we welcome other suggestions from readers). That should be enough to make decent bouquets during September and October.

Here are a few more ideas from our correspondents:

•Dave Dowling: “Asi-Florum lilies. Some varieties will bloom in 8-10 weeks - a quick return on a 40 cent investment. Last year I planted some July 15th and picked in late September, selling them for $3.00 at farmers markets and $1.25 to florists. Even planting them that late and picking just before frost they have still come back this year and look great, nice robust plants with lots of buds.
“Liatris will bloom in about 60 days during the summer. I’ll plant until early August.”

•Tammy Ford: “We throw in a little Bittersweet, although I don’t recommend planting it, as the Celastrus orbiculatus is a terrible weed in some parts of the country. We planted Sedum ‘Autumn Joy’, ‘Matrona’, and ‘Brillant’ last year but the jury is still out on that one. Looking back I see that we still have a few short stems of Lisianthus and Phlox paniculata late in season. This year we are going to try Salvia leucantha again although it is sometimes a rush to bloom before a frost gets it. We tried Callicarpa dichotoma for years but never could get the leaves to hydrate and removing them is not economically viable.”

•Joan Thorndike: “Other than those mentioned above, my very favorite fall flowers are monkshood, blue scabiosa fama, delphinium and helenium, all perennials. We also rely on what we hope will be a bounty of amaranths and a variety of cutting grasses. If the frost is kind to us, or if we have smartly planted in the cold frames, we do love our celosias and the dahlias.”

•Peggy Huff says that several new varieties would be worth a try for fall flowers. Two have just been named AAS winners for 2003.
Rudbeckia ‘Prairie Sun’ is similar to ‘Indian Summer’ but with a green center and petal tips of a lighter yellow. It’s hardy in Zones 4-9.
Pennisetum glaucum ‘Purple Majesty,’ is an ornamental millet with dark purple foliage and stems that grows 36 to 60 inches tall.