How to Plant and Grow Helenium

Add glorious late-season color to your landscape with helenium, also known as sneezeweed. This sun-loving native perennial delivers long-lasting floral displays each year from mid- to late summer through fall. It features bright green foliage that contrasts beautifully with velvety, daisy-like flowers. The species has primarily yellow flowers while cultivars and hybrids come in shades of orange, yellow, dark red, and golden brown. Most varieties feature flowers with petals in a stiff skirt that spreads out from the center. Others sport flowers with downward-facing petals in the manner of a shuttlecock.

Where to Plant Helenium

Select a site in full sun with well-drained, acidic soil.

Sneezeweed is the most attractive planted as a grouping or as a mass planting. Use it to add vibrant late-summer and fall blooms to borders, cottage gardens, naturalized areas, meadows, and prairie-style landscapes. It is also a fantastic addition to a pollinator garden, drawing all kinds of butterflies and bees.

How and When to Plant Helenium

To plant a potted nursery plant, dig a hole about twice the diameter of the pot and about the same depth. Place the plant in the hole and fill in original soil to the top of the root ball. Gently tamp down the soil and water it well. Keep it watered until the plant is established.

Space plants 3 to 4 feet apart.

Helenium Plant Care Tips

Like most native plants, helenium requires little care once established. Some of the taller varieties may require support or staking to keep plants upright.

Light

Plant helenium in full sun (at least six hours a day) to promote long-lasting displays of color. Although some varieties tolerate afternoon shade, this plant typically becomes floppy and leggy in part-shade conditions.

Soil and Water

Helenium needs well-drained, slightly acidic soil (pH between 5.5 and 7.0) and moderate moisture, which makes sense because its native setting tends to be low-lying meadows or the edges of damp woodlands. Water at least weekly, increasing frequency in times of extreme heat. Although similar in looks to both black-eyed Susan and coneflowers, this plant does not share their ability to withstand droughts. It also dislikes boggy areas, so make sure the planting bed doesn't retain standing water.

Temperature and Humidity

This perennial, which is native to much of the US and southern Canada, is adapted to a wide range of climates from Zone 3 to 8. While harsh winters are not a problem, the plant does poorly in areas with extremely hot and humid summers.

Fertilizer

If planted in fertile soil, the plant has no to moderate fertilizer needs. At the most, feed it a balanced flower fertilizer once per year in the spring.

Pruning

Helenium grows quickly and will require frequent deadheading in order to produce new flowers and reduce its fondness for self-sowing. Pinch deer-resistant helenium back in spring to make it shorter and bushier, possibly at the cost of delaying flowering. Once it's done blooming, cut the flower stalks down to the foliage. To provide food for wildlife during the winter, however, don’t cut back the seed heads until the spring to provide.

Potting and Repotting Helenium

Due to its size and the fact that the plant looks best in groups in a naturalistic landscape, helenium does not make a good potted plant.

Pests and Problems

Generally, helenium is not often affected by pests and diseases. The most serious disease is aster yellows. It is caused by a bacterial infection and cannot be treated. Dispose of infected plants promptly to prevent the disesase from spreading.

In humid weather, powdery mildew may occur; some varieties such as 'Butterpat' are more prone than others. Poor drainage and the presence of pathogens in the soil can lead to root rot. Potential pests on helenium include aphids, leafhoppers, thrips, and spider mites. Occasionally, slugs feed on the plants.

How to Propagate Helenium

With the exception of varieties that are protected by plant patents, helenium can be propagated by division or from seed. Even if you don’t need extra plants, it is recommended to divide helenium every three years in the spring after it comes out of dormancy to ensure vigor. Dig out the clump and separate it into smaller sections. Replant them at the same depth as the original plant and water it well until established.

Direct sow seeds outdoors 2 to 3 weeks before the last frost. In a warm climate, you can also plant the seeds in the fall. To get a head start on the growing season, start seeds indoors 8 to 10 weeks before the last frost. Using cell packs or flats filled with potting mix, press the seeds into the into soil but do not cover them as they need light to germinate. Keep them moist at all times at a temperature between 65 and 70 degrees F. Germination takes 10 to 21 days.

Transplant the seedlings outdoors after the last spring frost.

Types of Helenium

'Mardi Gras' Helenium

This hybrid, which was discovered as a chance seedling of two Helenium cultivars, bears 2-inch daisies in rich orange washed with yellow and red. Its upright clumps may reach 3 feet tall. Zone 4–8

'Moerheim Beauty' Helenium

Helenium 'Moerheim Beauty' seldom tops 3 feet. Its coppery-red ray flowers surround a darker disc. Zone 4–8

'Salsa' Helenium

'Salsa' (trademark name: 'Mariachi') is a dense, compact plant covered in bright orange and yellow blossoms beginning in late summer. Zone 3–9

'Dakota Gold' Helenium

'Dakota Gold' is an annual variety of Helenium amarum, commonly known as bitterweed. It only grows about 12 inches in height and has gold flowers and finely textured foliage.

Helenium Companion Plants

Obedient Plant

Obedient plant (Physostegia virginiana) is named for the way flowers that are moved to a new position on the stem stay in place, much to the delight of children. It produces showy, unusual flower spikes with little tubular flowers in white, pink, or purple. They're excellent as cut flowers. Square stems carry pairs of mid-green (sometimes variegated), lance-shaped foliage, toothed along the edges. Obedient plant tolerates most soils, but tends to become aggressive when given ample water and full sun. It tolerates most soils. Zone 3-9

New England Aster

Because the robust New England aster (Symphyotrichum novae-angliae) is one of the most popular asters native to North America, many cultivars have been bred so you have lots of choices. The species gets 3 to 6 feet tall and has an upright growth habit. The flowers have purple rays and yellow centers. Zone 4-8

Switchgrass

Switchgrass (Panicum virgatum) was originally the grass that dominated the native tall-grass prairies of North America. It is a tough ornamental grass that stands up to a variety of harsh conditions while adding both texture and color to a garden. It spreads slowly over time and adds stunning vertical accents wherever it is planted. It blooms in mid to late summer. Zone 4-9