What is Hieracium?

Hieracium is a very large genus of flowering plants in the sunflower family, most of which are classified as weeds. Members of this genus are closely related to plants like dandelion and chicory and they bear the distinctive yellow flowers seen on most members of their family. Although generally regarded as weeds, there are a few members of this genus with value as ornamental plants. Ornamental species are available at nurseries and through trades with other gardeners, although gardeners should be advised that they can become invasive.

These plants produce a basal rosette of leaves. Often, the leaves are hairy, and they may be simple, toothed, or lobed, depending on the species. Tall stalks produce tightly packed yellow flowers that go to seed in the fall. The seeds develop in puffs, allowing them to be easily dispersed by the wind and helping the plant spread through the natural environment. Although Hieracium dies back in fall, it has a perennial root and will return in the next year.

The number of species in this genus is a topic of debate. Some botanists estimate the number at hundreds, while others suggest there may be thousands. The sunflower family in general is one of the largest botanical families and the huge numbers of Hieracium species contribute significantly to those overall numbers. The species can be found variably throughout the world in an assortment of environments from roadside ditches to household gardens.

Ornamental cultivars are grown for traits like leaves with variegated foliage or unusually large and interesting flowers. Breeding has eliminated some of the classically weedy appearance, but usually not the invasive traits associated with Hieracium. Gardeners interested in cultivating ornamentals generally need soil of medium to poor quality and moisture, and a sunny to partly shady spot in the garden. It is advisable to trim back the flowers as they die off to prevent them from going to seed.

Many butterfly species are attracted to Hieracium. Wildflower reseeding with native species to cover and protect washed out or damaged soil may include some Hieracium species to attract butterflies and beneficial insects, and gardeners can plant ornamental species with similar goals in mind. Butterfly gardens, gardens specifically designed to appeal to butterflies, typically include a broad array of flowering plants and trees to entice as many species as possible. Such gardens can also lure nectar-seeking birds and insects, and providing a bird bath may be appreciated by garden visitors.