Elecampane (Inula helenium) is a perennial herb in the aster family with a long history of medicinal uses, though such use is less common today. In appearance, it is reminiscent of a sunflower plant, with tall stalks, pale green foliage, and bright yellow flowers with large seed heads in the center. The flowers of elecampane are much smaller than sunflowers, but it has enormous leaves that can grow to 2 feet in length. Elecampane is easy to grow but is not a notably showy plant. Once grown primarily for its use in herbal medicine, it is today grown mostly as a novelty in wildflower gardens or cottage gardens.
Elecampane is not a plant generally found in nurseries, so it is normally planted from seeds sown in mid-spring or started indoors a few weeks before the last frost. The plant typically will not flower its first year, but from the second season on, it should have robust blooms from early summer through early fall.
|Botanical Name||Inula helenium|
|Common Name||Elecampane, horse heal, elfdock|
|Plant Type||Perennial herb|
|Mature Size||3–6 feet tall, 2–3 feet wide|
|Sun Exposure||Full sun to part shade|
|Soil Type||Any well-drained soil|
|Soil pH||6.5–7.5 (neutral)|
|Bloom Time||Summer to fall|
|Hardiness Zones||3–7 (USDA)|
|Native Area||Eurasia; naturalized in North America|
How to Plant Elecampane
Elecampane needs some room to grow and should be planted 12 to 30 inches apart. It is easy to grow from seed and can be divided once mature. Elecampane spreads via rhizomes, underground "runners" that bear both roots and upward-climbing shoots. While many other rhizomatous plants are aggressive spreaders, elecampane is more subdued and rarely becomes invasive. In ideal conditions, it can self-seed and grow new plants from fallen seeds. If desired, you can divide large plants every few years.
As befits a plant that naturalizes so readily, elecampane has few serious pest and disease problems.
Elecampane grows best in part shade but will tolerate full sun.
Soil conditions for elecampane do not need to be precise, provided the soil is well-drained. The plants can tolerate a range of soil types, from sand to clay. Moist, semi-fertile loam is ideal.
Water as needed to keep the soil moist but not wet. As a wildflower, elecampane does not require a precise watering schedule, but proper, deep watering will help produce healthy roots for harvesting.
Temperature and Humidity
Elecampane grows in a wide range of climate types and temperatures, but it does best in zones with mild summers and cold winters. It does not grow well in very hot and humid areas.
There is no need to feed elecampane flowers with commercial fertilizers or flower food, and organic feeding is best if you plan to harvest the roots for medicinal uses. Simply top-dress the soil with compost in spring.
There are no named cultivars of elecampane, but there are three other species in the Inula genus which are sometimes confused with this plant:
- I. britannica (British yellowhead) has flowers similar to elecampane, but the leaves are much smaller. It can be an invasive plant if it escapes cultivation.
- I. hookeri (hooker inula) is similar in appearance to elecampane, but is generally a shorter plant, rarely growing more than 3 feet tall.
- I. salicina (Irish fleabane) is an increasingly rare wildflower species that grows to about 2 feet tall. Its leaves are much smaller than elecampane, though the flowers are quite similar.
Use caution when using harvested plants for medicinal purposes. When used in commercial herbal preparations, elecampane is usually blended with other herbs to create supplements aimed at supporting respiratory health. Used alone, the roots are cleaned, chopped, then used in teas or tinctures. But there is evidence that consuming large amounts can make you ill, so this is not a plant to use casually.
If you want to harvest the roots of elecampane, do so in the spring or fall season, beginning in the plant's second year or later. It has a very large and sturdy taproot that requires some digging to harvest. The roots and rhizomes spread out in an octopus shape, so dig a broad area to retain as much of the root as possible. Digging with a pitchfork helps to loosen the soil without damaging the roots too much, but a shovel works fine, too.
You can harvest the entire plant if desired. Or, if the plant is large, you can essentially divide it and harvest just a portion of the root growth and foliage. The foliage likely will have died back and is not worth preserving in any case.
After harvesting the plant, cut off the foliage and clean the roots well. Squeeze the tough outer skin of the root by hand to break it apart, then peel it away to expose the clean, white root interior. Prepare the root interior as desired.
Propagate elecampane with cuttings in the fall, after harvesting the root. Select a healthy piece of root that is about 2 inches long and contains a bud or eye. Plant each cutting about 12 inches deep, spacing them at least 12 inches apart. Water the area until the ground freezes. In spring, water carefully to keep the soil moist. The resulting plant should be mature in two years.
How to Grow Elecampane From Seed
Elecampane is easy to grow from seeds. If sowing in the garden, plant them after all danger of frost has passed. Or, you can plant them indoors, in a greenhouse, or in a cold frame a few weeks before the last frost. The seeds need light to germinate, so sow them on the surface or under a very light layer of soil that sunlight can penetrate. Keep the soil moist. The seeds should germinate in about two weeks. Transplant the seedlings to the garden once they sprout two sets of leaves.