Growing perennials from seed is a job that usually takes two to three growing seasons to pay off with flowers for your garden. With some varieties of Echinacea or coneflower (Echinacea purpurea), perennial in U.S. Department of Agriculture plant hardiness zones 3 through 9, you can see the daisy-like blooms with the spiky domed centers in late summer of their first year. The secret lies in selecting the right cultivar and cheating the season with an early start.
Fill a clean planting flat with moist seed-starting mixture approximately six to 10 weeks before your area's last frost date or before daytime temperatures are consistently about 70 degrees Fahrenheit.
Scatter the seeds of an Echinacea cultivar known for flowering in their first season across the top of the tray, and cover the seeds lightly with 1/4-inch seed-starting mix. Echinacea seeds need to be covered to germinate.
Set the tray in a dark location where the air temperature is between 70 and 75 degrees Fahrenheit. A seed-starting mat can be placed under the tray if your room is not that warm. Keep the seed tray moist and seeds can germinate in as little as four to five days. The warmer the temperature, the more quickly seed will sprout.
Move the tray to an area where it can receive full sun for 10 to 11 hours a day. This may require keeping the tray under grow lights on a timer.
Transplant the small seedlings into individual 4-inch pots in potting soil, setting the plants at the same height they were in the tray. Reduce the temperature to 65 to 70 degrees F.
Fertilize the seedlings with a low-phosphorus liquid fertilizer like a 15-0-15 at a rate .8 ounces in 1 gallon of water. Afterwards, keep them evenly moist.
Adjust the lighting to 14 hours on and 10 hours off to get the plants to bud. According to "Greenhouse Product News," when forcing first-year Echinacea into flower, 14 hours is the optimal day-length for encouraging flowering. Once the flowers bud, the amount of daylight is no longer important.
Transition the plants to the outdoors when daytime temperatures are 60 to 75 degrees F and nights are 50 to 60 degrees F. Leave them outdoors in a sheltered area for an increasing number of hours over a week until they are outdoors all night.
Plant your Echinacea in full sun to partial shade in well-drained soil. Set the plants slightly above the soil line to prevent stem rot and 18 to 24 inches apart to improve air circulation to avoid powdery mildew and mold.
Things You Will Need
- Planting flat
- Seed-starting mix
- Nursery heating mat (optional)
- 4-inch pots
- Potting soil
- 15-0-15 fertilizer
- Cultivars suitable for forcing include "PowWow Wild Berry," "PowWow White," "Cheyenne Spirit," "Prairie Splendor" and "Pink Parasol."
- Plants should flower in June if started in January under warm conditions with controlled lighting. Starting the plants early and using natural light can produce first-year bloom, although they may not flower until late in the season the first year, depending on the temperature.
- Missouri Botanical Garden: Echinacea Purpurea "PowWow Wild Berry'"
- University of Illinois Extension: Purple Coneflower, Echinacea Purpurea
- Herbaceous Perennial Plants; Allan M. Armitage
- Diane's Flowering Seeds: First-Year Flowering Perennials
- Grower Talks: Controlling Flowering of Echinaceas
- Greenhouse Products News: "PowWow" Echinacea
- CSU Extension Greenhouse Advisor: Fertilizer Calculations: Understanding Parts per Million
- Hallson Gardens: Planting Instructions for Echinacea
- Andy Sotiriou/Photodisc/Getty Images