The Annual Sow Thistle is a winter annual weed that is soft and not as prickly to the touch as Spiny sow-thistle.  Plants are coarse, erect, and can reach about 4-3/5 feet (1.4 m) in height. The stem is smooth, thick, hollow between stem joints (nodes), and secretes a milky sap when cut. The leaves are hairless somewhat bluish green. The upper leaves are smaller than the lower leaves, stalkless, and clasp the stems with claw-like basal lobes. Lower leaves are usually about 4 to 8 inches long, with a tapered or winged base, and are deeply lobed. The terminal leaf lobes are much larger than the lateral lobes.

S. oleraceus is a common seed crop contaminant and has been carried either deliberately or accidentally by humans to almost every corner of the earth, where it invades mainly open and disturbed areas. It grows in a wide variety of environments on a wide range of substrates – roadsides, cultivated land, gardens, construction sites, sand dunes, logged or burned areas, on walls, mountain slopes, and near water. Once introduced to a new area the plants spread quickly because they grow and flower quickly and produce copious wind- and bird-dispersed seeds that germinate quickly in large numbers. They invade many cropped areas, especially among vegetable and winter crops. Additionally, this species has small light seeds which are easily dispersed by wind and water.

Flowering generally takes place in the spring and summer and under favorable conditions, year-round. Flowers cluster at the stem tips to form daisy-like flower heads. When closed the flower heads are urn shaped. Flower heads mature into white, fluffy seed heads, although not ball-shaped like in dandelions.

Organic control of this weed includes hand digging the tap root.  Mowing or digging should be done before the plant goes to seed.  Mulching well will keep any seed from landing and germinating in a bed.  Young plants love growing in moist areas.Ann