Boneset is a plant native to the wetlands of North America that has a long medicinal history and an attractive, distinctive appearance. While it is still sometimes grown and foraged for its healing properties, it may also appeal to American gardeners as a native plant that attracts pollinators. Exactly what is boneset? Keep reading to learn more about how to grow boneset and common boneset plant uses.
I. Appearance and Characteristics
Eupatorium perfoliatum, known as common boneset or just boneset, is a North American perennial plant in the family Asteraceae. It is a common native to the Eastern United States and Canada, widespread from Nova Scotia to Florida, west as far as Texas, Nebraska, the Dakotas, and Manitoba. It is also called agueweed, feverwort, or sweating-plant.
The name “boneset” comes from the use of the plant to treat dengue fever, which is also called “break-bone fever.” It is nearly always found in low, wet areas.
Eupatorium perfoliatum grows up to 100 cm (39 inches) tall, with opposite, serrate leaves that clasp the stems (perfoliate). The stem is hairy. The plant produces dense clusters of tiny white flower heads held above the foliage. In Illinois, the plant blooms during late summer and early fall. Its native habitats include damp prairies, bogs, and alluvial woods.
Eupatorium perfoliatum can form hybrids with other species of the genus Eupatorium, for example Eupatorium serotinum.
II. How to Grow and Care
Sunlight
Boneset tolerates partial shade but it will flower better if you give it full sun.
Temperature and Humidity
The above-ground foliage will die back in the winter, but its roots can handle temperatures down to -13 degrees Fahrenheit. It thrives in hot and humid conditions.
Watering
This plant prefers constant moisture and can even withstand a few days of mild flooding. Monitor the soil moisture level by inserting a tip of your finger about an inch deep; the soil should feel moist. If it doesn’t, water it thoroughly. Do not let the soil dry out completely.
Soil
Tolerant of a wide range of soil conditions, boneset is best grown in sandy soil or clay-type soil. Since this plant prefers its soil to be constantly moist, give it extra water if you grow it in sandy soil. Sandy soils are like sieves; they do not hold water well.
Fertilizing
Boneset performs best in soil with only average fertility. If you are planting it in compost-enriched garden soil, you should not need to fertilize it at all. If you choose to fertilize, don’t give it too much fertilizer; only use a quarter-strength and once at the beginning of the growth period in the early spring after the ground has thawed.
Pruning
Using sterilized pruning shears, you can cut back the plants once dieback occurs as the cold weather sets in. Or, you can wait until early spring and cut back nearly to the soil level. Prune back again in the summer to encourage bushy growth and abundant blooms. Deadheading will not help this plant rebloom, but it will help control seed and plant overgrowth.
Propagation
Boneset is best propagated via sowing seeds or root division. Boneset spreads by underground rhizomes that often crowd an area. To prevent overcrowding and keep the plant robust, divide the plant at least every three years. Divide in the fall just as the plant appears to die back or go dormant or when new shoots appear in the spring. Here’s how to propagate by division:
- You’ll need a hand shovel or spade to dig up a section of the plant, and if you’re replanting it in a pot, you’ll need a clean pot and fresh potting soil.
- Measure a radius of 6 to 8 inches from where the stem comes out of the ground, and start digging a circle around the plant.
- Dig around and under the plant, carefully digging up the underground root structure and root ball. Cut the rhizome into pieces.
- Replant the root sections in the ground at their original soil depth and water the soil well.
How to Grow from Seed
Seeds can be sown directly in the ground in the fall or in the spring after being cold stratified. Cold stratification tricks the seeds into thinking winter is over, and it’s time to grow.
To direct-sow seeds outdoors:
- If direct sowing outside in the fall, scatter many seeds around in lightly raked soil. You’ll use more seeds to ensure germination success since it is unreliable in an uncontrolled setting. Keep the area moist throughout the fall
- If directly sowing outside in the spring, germination success is more reliable if you cold-stratify the seeds in the refrigerator for at least four weeks. Sow the seeds as soon as soil is workable.
To sow seeds indoors:
- Start the seeds by cooling them in a refrigerator for 4 to 6 weeks.
- Using your finger, press the seeds into a bed of moistened sphagnum moss or seedling mix. No need to cover the seeds.
- Place it in bright, indirect light and keep the temperature between 70 to 85 degrees Fahrenheit.
- Keep the potting mix moist throughout the process.
- It can take two to three months to germinate.
Potting and Repotting
Seedlings are slow growers and can take up to a year before maturing. After a year of growth as a seedling, you can repot it in a permanent location in the ground or a larger planter. Boneset spreads when it grows. It needs a large container—at least 12 to 15 inches in diameter—with ample drainage holes.
Overwintering
This perennial plant naturally dies back as soon as temperatures fall. Once leaves and stems turn yellow, you can cut them down or keep them intact until early spring. Protect the root system with a three-inch layer of mulch if you live in an area where you expect a deep winter freeze.
Pests and Diseases
Common Pests
Grasshoppers, flea beetles, lygus bugs, weevils, sawflies, and several species of moth caterpillars like to feed off of boneset leaves. Insect activity leaves the plant looking ragged, but it can recover from infestations.
Try less invasive controls first, such as insecticidal soap and horticultural oil, to control bug activity. If those do not work, consider using pyrethrin, a natural pesticide extract derived from chrysanthemum flowers.
Common Problems
Boneset is relatively easy to grow and rarely experiences any problems. It does particularly well in wetlands and near water. It is not prone to any usual plant diseases.
Shriveling Leaves
Boneset is susceptible to leaf scorch or shriveling leaves when it does not get enough water. While it can tolerate a short drought, ensure it gets ample water, especially during the hottest summer months.
Foliage or Stems Falling Over
Giving this plant too much fertilizer can bring on leggy growth and cause this plant to fall over. Boneset does not require feeding. A compost-enriched soil works best to get this plant the nutrients it needs. If you plan to use fertilizer, dilute it, and only give it once at the beginning of the growing season as new spring growth emerges.
III. Uses and Benefits
- Ornamental uses
This tall, robust wildflower is versatile in the garden. It performs best in gardens where it’s allowed to naturalize freely, including the middle positions in mixed borders, and in cottage, native, and bog gardens. It makes an excellent addition to naturalized areas such as prairies and meadows. Boneset is also attractive to pollinators and is therefore a useful component of native wildlife and pollinator gardens.
- Traditional medicine
Eupatorium perfoliatum (also called boneset) was used in traditional medicine by Native Americans who applied extracts for fever and common colds. By the early 20th century, it was reported as commonly used by rural African-Americans in the Deep South to treat fever, including dengue fever, though it was considered less effective for yellow fever and typhoid fever. Possible effects of E. perfoliatum for these uses remain undefined by adequate scientific research, and are unconfirmed by high-quality clinical research. If consumed in large amounts, tea made from its leaves may cause diarrhea.
