Common Ragweed

Ambrosia artimisiifolia

Common Ragweed produces numerous slender spikes of small green flowers, which produce large quantities of the yellow pollen that causes hay fever from the last week of August well into the fall. The flowering spikes are about 1/4 inch wide and usually between 1 and 3 inches long, though they may be longer. The reddish stems are finely hairy.  The leaves are finely dissected, and may be several inches long with deep, pointed, opposite lobes.

Despite the misery it causes through hay fever, this native species is an major source of food for songbirds and a variety of beneficial insects, especially in late fall and winter, when the oil-rich seeds and pollen are an important source of energy.


1-4 feet, sun - partial sun.


Late Summer- Autumn (August-October).

  A specimen showing the plant's tendency to produce many branches with flowering heads.

10 August 2020.

Common Ragweed, 9 August 2020.