How to Grow Parthenium

Parthenium are a perennial herb related to the aster family. They are native to the eastern and midwestern region of America. Oval to lance-shaped leaves are variable in size and have toothed or lobed edges, often producing a mild and pleasant fragrance. Huge, flat topped clusters of pale blooms mount long, thick stems throughout late spring and summer. They are best suited to flower beds and borders within cottage, prairie, wildlife and informal garden settings. You should expect to see Parthenium grow to an approximate height of 70-90cm (28-36”) and a spread of 50cm (20”).

Parthenium are best planted in moist, well-drained soil of sand, loam and clay. They are best positioned in full sun but will tolerate part shade if necessary. You may wish to amend the soil with organic matter or compost at the time of planting. Ensure there is space between companion plants so they can spread freely whilst growing to their individual mature height and spread.

Water Parthenium freely throughout active growth, making sure they are kept moist, especially during periods of drought. You can cut and dry these flowers for ornamental purposes. You should not need to prune Parthenium other than to remove old, dead and damaged foliage.

It is possible to propagate Parthenium by seed during the winter.