For the hard-working flower farmer, September may seem like the time for coasting. You’ve worked steadily since February or March, you’re tired, and your flowers are no longer as exquisite as they once were. But in your heart you know that you have to rally and start work on next year’s flowers.
In most parts of the country, now is the time to plant those crops that will bloom early next spring: Bulbs, biennials, perennials and cold-hardy annuals. Important crops such as larkspur MUST be planted now in most parts o t the country to provide adequate chilling.

In the mountains, upper Midwest and inland northeast, it’s too late to plant anything except bulbs; other crops will have to wait till spring.

Choosing what and when to plant depends on two factors: when your first hard frost is expected and how cold your winter will be. If you aren’t sure about how late you can plant, and you can’t afford to lose expensive plant material, restrict yourself to seed, which is cheap, and bulbs, which are certain to survive. You can learn more about the planting limits for your garden by experimenting with a small number of plants from a garden center. Next year, you’ll have more confidence about the best time for fall planting in your area.

Several expert flower growers around the country shared their fall planting schedules to help you figure out the best time for your area:
•Betsy Hitt, near Raleigh, North Carolina, is in Zone 7 with an average first frost date of October 20. Betsy starts on September 15 with direct-seeded bachelor buttons and hesperis, plus transplants of sweet william, foxglove, lupine, penstemon and gloriosa daisy. On Oct. 1 she seeds larskpur, nigella, agrostemma, coreopsis, and bupleurum. Also on Oct.1, she transplants scabiosa, delphinium and snapdragons. A second planting of larkspur is made on Oct. 15. On Nov. 1, she plants larkspur, nigella, Dutch iris, Asiatic lilies and daffodils.
•Ralph Cramer of Cramer’s Posie Patch in Lancaster, Pennsylvania, is in Zone 6 with an average first frost date of Oct. 20. He direct seeds in the first half of September: Larkspur, bupleurum, pennycress, nigella, atriplex, candytuft, agrostemma,hesperis, and saponaria. Ralph covers those crops with row cover in November.
•Here at Wild Onion Farm near Lawrence, Kansas, we’re in Zone 5 with an average first frost of Oct. 20. We divide perennials and transplant perennials and biennials the first half of September. We direct seed larkspur, agrostemma, nigella, and bupleurum between Sept. 15 and Sept. 22.
•Huey Kinzie of Stoney Point Flowers in southwestern Wisconsin, Zone 4, has an average first frost date of Sept. 30. He said that they have usually been successful seeding larkspur in November and covering with row cover.

One caveat is that all fall-planted material should be planted in well-drained soil. Wet feet – and the root rots that result – are the greatest threat to fall-planted crops. On the other hand, it may still be hot and dry when you plant, so be prepared to keep those beds supplied with adequate water. And if you have a winter drought, you will have to water throughout the winter, too.
With those factors in mind, here are some suggestions for fall planting that will pay off handsomely next year.

Perennials
In general, perennials from plugs or other containers need six to eight weeks before hard freeze to get their roots established. In the north, that opportunity may have already passed, but for growers with a freeze date of late October and beyond, you can plant now. If frost threatens before the plants look established, mulch them and cover with row cover to give them a couple of weeks extra growth before winter sets in. Remember that the biggest threat to young plants is heaving as the ground freezes and thaws; if that’s your usual winter weather pattern, you might want to forget about buying expensive plants now and wait till spring to plant them.

Divisions of your own plants are quicker to establish, so you can move them now. Don’t forget that many of your perennials need to be divided to keep yield high and stems long. Three to five years is about the maximum production time before most perennials need to be divided. Those that spread quickly such as yarrow especially benefit from division. If you have a field that has been taken over by rampant plants such as lysimachia or monarda, you can even plow or till strips through them to rejuvenate the plot.

Trim the divisions to eliminate excessive foliage. Plant into well-tilled soil that contains adequate phosphorous and potassium for root growth. You can add colloidal phosphate or greensand if your most recent soil test showed a deficiency; avoid fertilizers that are high in nitrogen at this time of year, unless your soil has a serious nitrogen deficiency. Keep the transplants evenly moist. If it’s really hot, you should provide some shade for a week or two until the plants get established. Once the weather cools off, you should see the plants putting on new growth; that’s a good sign, but you don’t want too much new growth as frost approaches, so don’t fertilize.

Biennials
Sweet William, foxglove, lupine and hesperis are three good cut flowers that can be planted now for early harvest next year. Biennials require a long period of vernalization – 12 weeks or more of 40°F or colder. But you need fairly large plants to set out this late, so if you haven’t planned ahead by seeding your own in mid-summer, you may have to purchase plugs from a plug supplier. If you don’t have a regular plug supplier, call Germania Seed at 800-380-4721 or visit their web site at www.germaniaseed.com. Germania brokers for a number of plug suppliers and may be able to find what you need. Even with plugs, you should use row cover once frost threatens to give the plants additional time to settle in.

Hardy annuals
Hardy annuals either require a long period of vernalization or they tolerate cold weather. Some of the best – and certainly the earliest – cut flowers fall into this category. In Zone 5 and warmer, most hardy annuals will germinate as soon as the soil cools to their optimum temperature. They will form small plants before hard freeze, then go dormant for the winter. They will resume growth once the soil thaws in early spring, and bloom soon after bulb crops have finished. In Zone 4, some growers plant late and the seed sits dormant until the soil thaws in late winter. Still, fall seeding is not assured success in Zone 4. One indicator of whether you can fall plant is how reliably your hardy annuals self seed; if you have larkspur and bachelor buttons popping up all over, you should try fall seeding.

If your soil texture permits direct seeding, use an Earthway seeder. Choose a seed plate for a vegetable that approximates the size of the flower seeds you’re planting. The radish or onion plate can be used for larkspur. Experiment with different seed plates for different flowers. Don’t be afraid to uncover the seed after you’ve planted to see if it’s as thick as you want. Seed is cheap! Some growers tape every other hole on a seed plate closed or mix the seed with vermiculite to reduce planting density. In any case, don’t thin until spring when you know what has survived.

Larkspur, bachelor buttons and agrostemma don’t usually need row cover, but other fall-seeded annuals may do better covered in very cold winters.

Bulbs
Perennializing bulbs such as daffodils and alliums should be planted in permanent beds, using the same methods you would use when planting them in a landscape garden. Pay attention to hardiness zones on alliums. If you are in a marginal area, use row cover to protect them. If you’re well within the hardiness zone, row cover is a disadvantage because it causes them to bloom earlier, making them more susceptible to late frosts.

Lilies can be planted now , 6 inches apart, with 6-8 inches of soil on top. If you want them to produce more than one year, you will have to leave at least a third of the stem. Otherwise, treat them as an annual.

Tulips also can be treated as perennials, but most commercial growers pull them, bulb and all, when harvesting. Mimo Davis and Kelly Anderson of Wild Thang Farm near Columbia, Missouri, plant their tulip bulbs using the “eggs in a carton” method of spacing, which means the bulbs are so close they almost touch but not quite. They placed the bulbs firmly on top of the ground, then used the loader on the tractor to dump six inches of soil over them.

When tulip bulbs arrive, be sure to ventilate them right away and keep them from sources of ethylene, including ripening fruits and vegetables, rotting plant matter, internal combustion engines and unventilated heaters. Ethylene can cause stunted and uneven growth and withered flower buds.