How to Grow and Care for Helenium (Sneezeweed)

sneezeweed helenium

The Spruce / Adrienne Legault

Allergy sufferers need not worry about planting the sneezeweed, as the common name for helenium derives from a long-lost use of the ground plant as a snuff ingredient. After inhaling, the resulting sneeze was said to drive evil spirits from the body. The only creatures apt to be affected by the blooms of helenium are butterflies, which seek out this late-flowering plant.

As a native plant, helenium grows in moist, low-lying meadows or at the edges of damp woodlands. Horticulturists have taken the genus far beyond the simple yellow daisy-like flower of the native type, expanding the varieties to include every conceivable shade of gold, orange, red, and brown.

The full Latin name of Helenium autumnale is a reference to Helen of Troy, although the plants are native to the Americas, and the fall blooming time. The Helenium is a member of the Asteraceae family, which includes many similar-looking daisy-like flowers such as coneflowers, cosmos, blanket flowers, and sunflowers. You may have seen stands of helenium growing in the moist areas it loves in growing zones 3–8. The plants are characterized by lance-shaped foliage with stiff, upright stems that rarely need staking. Planted in early spring, helenium plants grow quickly to a mature size of three to five feet tall and spread to 24 inches wide.

Botanical Name Helenium autumnale
Common Name Sneezeweed, Swamp sunflower
Plant Type Perennial flower
Mature Size 35 feet tall
Sun Exposure Full sun
Soil Type Well-draining
Soil pH 5.5 to 7.0
Bloom Time Fall
Flower Color Yellow, gold, orange, coppery brown, red
Hardiness Zones 38 (USDA)
Native Area the Americas
sneezeweed used in a landscape
The Spruce / Adrienne Legault
helenium
The Spruce / Adrienne Legault 
helenium
The Spruce / Adrienne Legault

How to Grow Helenium

Helenium plants are easy to grow from seed, but gardeners may want to start with named hybrid varieties only available as plants. If you choose seed starting to get a large colony of helenium quickly, don't cover the seeds, as they require light to trigger germination. Plants will germinate in about two weeks at room temperature.

Light

Helenium flowers will get leggy if they don’t receive at least six hours of sun each day, but they will accept some afternoon shade, especially if the planting area is on the dry side.

Soil

Helenium plants like their soil on the acidic side, with an ideal pH range of 5.5 to 7.0. Place heleniums where they will enjoy moist conditions, but not in a boggy site. Consider a rain garden site where moisture naturally collects, such as a low-lying area or beneath a downspout. Well-draining soil is best, but heleniums are clay tolerant.

Water

Although helenium flowers resemble coneflowers and black-eyed Susan flowers, they do not share the drought tolerance of these look-alikes. In fact, heleniums like moderate to heavy moisture, hence the nickname swamp sunflower. A three-inch layer of organic mulch will conserve moisture and maintain the acidic soil pH heleniums like.

Temperature and Humidity

Helenium plants tolerate humidity and hot summers, but proper spacing is important to prevent fungal diseases like mildew and rust where humidity is high.

Fertilizer

Heleniums aren’t heavy feeders, and one application of a balanced flower fertilizer in the spring is enough in fertile soils. Excessive fertilizer causes lanky growth, but pinching heleniums back in the spring encourages branching. After blooming, cut the flower stalks down to the foliage. Divide plants in the spring or fall every three years to keep plants vigorous.

Garden Design With Helenium

The simple form of helenium flowers suits cottage gardens and wildflower gardens. Pair helenium plants with other moisture-loving ornamentals that peak late in the season, like beautyberry or hibiscus. Plant helenium plants in groups of three or five for the best effect.

Deer seldom browse helenium plants, making them a natural choice for meadows, prairies, and other naturalized areas that must accommodate wildlife.

Heleniums make excellent, long-lasting cut flowers to make seasonal bouquets with other autumn beauties like sunflowers, asters, or sedum.

Varieties of Helenium

For such a seemingly simple and underused perennial, the number of helenium varieties is surprising. Variations in flower form, height, and color allow a gardener to devote an entire plot to growing helenium if he wishes. Here are a few of the most interesting selections for your garden:

  • 'Adios': Purplish-brown prominent cones; downturned petals
  • 'Beatrice': Yellow petals more upward than most varieties; yellow and brown cone
  • 'Butterpat': Pure yellow flowers from petals to cone
  • 'El Dorado': A large brown cone flanked by a petticoat of lemon-yellow petals
  • 'Red-Haired Katy': Petal color seems to shift from crimson to copper depending on the light
  • 'Waldtraut': Long blooming time; orange petals flecked with gold
all-yellow helenium
The Spruce / Adrienne Legault 

Plants Similar to Helenium

At first glance, helenium flowers and blanket flowers (Gaillardia grandiflora) seem to be almost identical. Both plants feature daisy-like flowers in bright red and gold hues. However, a key difference between the two sun-lovers is the amount of moisture required for thriving plants. Helenium plants need ample moisture and do well in a rain garden. Blanket flowers are very drought tolerant and need only occasional irrigation.

Helenium flowers look similar to coneflowers (Echinacea spp.) in that petals face outward from a central cone in a ray shape, or may droop downward. You can distinguish helenium from coneflowers by its late summer into early fall bloom time; in contrast to the early summer blooms of coneflower. Helenium flowers also differ from coneflowers in water needs and don't exhibit the same drought tolerance that coneflowers do.

Blanket Flower
Blanket Flower. Rüdiger Katterwe / Getty Images 
Yellow Coneflower
Yellow Coneflower. 500px / Getty Images