What Is Groundsel?
Groundsel is a tall, rapidly-spreading weed that is easy to spot thanks to the bright yellow flowers it displays. Livestock farmers should take note if groundsel is spotted on their grazing property, as the weed is highly toxic to cattle and horses.
The groundsel weed, sometimes also called Old-man-in-the-spring, gets its name from a shortened version of the old English word for "ground swallower," a term indicating how rapidly the weed can take over a field if left untreated.
Groundsel Height
Groundsel is an upright or erect weed, producing multiple branches from the main stem and averaging 6 to 18 inches in height.
Groundsel Shape
Groundsel weeds grow as upright stems, and the leaves it produces are lance-shaped or oval with serrated edges. Some groundsel leaves are deeply split in the middle.
Leaves and Flowers on Groundsel
The leaves of groundsel weeds are lance- or oval-shaped, and often split down the middle. Groundsel leaves have toothed edges.
Groundsel produces small, round yellow flowers in clusters and puffy white seedheads called pappus. The pappus behave like a dandelion puff and allow for seed distribution on the wind. These seed pods very closely resemble those of a dandelion, but the plants can be distinguished by their differing flowers. The groundsel flowers stay compact and appear to be closed, while dandelion flowers are a traditional ring of yellow petals in ray formation.
Groundsel Roots
Groundsel's roots are usually shallow, with branching roots spreading out from a short taproot below. Because of these loose, shallow roots, groundsel is easier to hand-pull than many other weeds.
When Does Groundsel Grow?
Groundsel is more versatile than many other weeds and can behave as a winter annual or a summer annual in milder climates. In Northern states where the winters are colder, groundsel weeds only flourish during the spring and summer months of growing season.