Coneflowers are quintessential prairie plants. Native to eastern North America, they are hardy, drought-tolerant, long-blooming, and cultivated in an ever-widening range of colors. It's hard to find a garden without at least one variety of the bloom. Best planted in early spring (after the final frost), coneflowers will germinate in about three to four weeks and produce leaves in three months but can take up to two years to actually produce blooms.
Purple coneflower, or Echinacea purpurea, is by far the most popular variety of coneflower. It has a fibrous root system, rather than the long taproot and woody crown found in other native species, making it more adaptable to garden conditions, and more forgiving of dividing and transplanting.
Coneflower's daisy-like booms are actually made up of several small flowers, with petals that are sterile to lure insects toward the many fertile flowers in the central disk or cone. These flowers are rich in nectar and very popular with both bees and butterflies. Hummingbirds also enjoy coneflowers, and birds like finches eat (and spread) the seeds.
|Botanical Name||Echinacea purpurea|
|Common Name||Purple coneflower|
|Plant Type||Herbaceous perennial|
|Mature Size||2–5 ft. tall, 1–2 ft. wide|
|Sun Exposure||Full sun, partial shade|
|Soil pH||Neutral to acidic|
|Flower Color||Purple, pink|
|Hardiness Zones||3-8 (USDA)|
|Native Area||North America|
Purple Coneflower Care
Purple coneflowers grow well just about anywhere in USDA hardiness zones three through nine, but in colder climates, you may want to give them a little winter protection in their first year. However, once established, coneflowers are rugged and hardy.
Coneflowers grow well from seed and can be divided to make new plants. They can also be grown from stem cuttings, but often with less success. They're easily found in garden centers and can also be purchased via mail order. Coneflowers start blooming in early summer and will repeat-bloom throughout the first frost. They may take a break after their initial bloom period, but they will quickly set more flower buds.
To get the most blooms (and the sturdiest plants), plant your purple coneflowers in a spot that gets at least six to eight hours of full sunlight each day. The plants will tolerate partial shade, but may eventually flop over, and the blooms won't be as prolific.
Coneflowers grow best in a garden that boasts a neutral soil pH of about 6.5 to 7.0. They can thrive in a variety of soil types, including sandy, rocky, and clay soils. However, they do not like wet or mucky soil. For best results, add a bit of compost to your mixture when planting to give your coneflowers successful a good start.
Coneflowers are often listed as drought-tolerant plants, but they will actually do much better with fairly regular watering. Water them daily just after planting, then transition to an inch of water per week for the rest of the plant's first year of life. Second-year and older plants may only need watering during droughts.
Temperature and Humidity
As a native prairie plant, purple coneflower thrives in hot, dry climates but can handle a range of temperature and humidity fluctuations. However, they do not do as well in very humid climates, or in rainy areas where the soil stays wet.
Although coneflowers thrive best in a soil high in organic matter, too much supplemental fertilizer can cause them to become leggy. Adding compost each spring usually gives them the nutrition they need for healthy foliage and blooms.
Pruning Purple Coneflower
Pruning purple coneflower is helpful, but not imperative. You can leave the plants standing throughout the winter months to feed the birds, and shearing them back in the spring will result in bushier plants that bloom longer into the season.
That being said, deadheading is the primary maintenance for coneflowers. They are prolific bloomers, and deadheading (removing the dead flowers from living plants) will keep them in bloom all summer.
Flowers start blooming from the top of the stem, and each flower remains in bloom for several weeks. As the initial flower fades, more side shoots and buds will form along the stem. Keep the plants deadheaded, and you'll keep getting more flowers. The process will also help prevent an overabundance of self-seeding from the plant.
How to Grow Purple Coneflower From Seed
Purple coneflowers are relatively easy to grow from seed. If you'd like to save the seed, wait until the cone has fully dried—it should be darker in color and stiff to the touch. The seeds are attached to the sharp spines, so you'll want to wear gloves, and separate the seeds from the cone. Spread them on a paper plate or screen to dry thoroughly before storing.
The seeds germinate best with some cold stratification. The easiest method is to sow them outdoors in the fall, either in the ground or winter sowing them in milk jugs. If you are going to start seed indoors, simulate the chilling period by planting seeds in a damp seed starting mixture and placing the sealed container in the refrigerator for eight to 10 weeks. Then, take them out and plant them as you normally would. The seeds need darkness to germinate, so plant them about half an inch deep and cover them with soil. They should germinate within 10 to 14 days. Place the seeds under grow lights that are about an inch or two above the plant once the seedlings emerge.
For the most part, coneflowers have very few problems. As long as the plants are given plenty of room for good air circulation, they should not be bothered by fungal diseases. If you see mildew or spots on the leaves, simply cut them back and let them fill in on their own. A few pests enjoy coneflowers, so keep an eye out for Japanese beetles, aphids and leafhoppers.
Also keep an eye out for aster yellows, a systemic plant disease that causes growth deformities in the flowers. It can affect hundreds of different flowers, not just those in the aster family. There is no known cure and it is spread by sap-sucking insects like leafhoppers, so affected plants should be removed and destroyed as soon as possible in order to protect other nearby plants.