Common sorrel is a short-lived perennial weed also known as sheep sorrel and red sorrel. It is a native of Europe and Asia and probably came to America in the mid to late 19th century. Today it is spread throughout the United States including Alaska and Hawaii, and is considered a noxious weed in at least 23 states. It thrives in full sun and gravelly or sandy soils with low fertility and high acidity. It is considered an indicator plant for highly acid soil. Common sorrel invades disturbed sites such as gardens, pastures, meadows, roadsides, and lawns where it is especially troublesome.
Description: The arrow head-shaped leaves of common sorrel are 4 to 12 inches long and form a rosette until flowering time when erect, ridged stems are produced that are 6-18 inches tall, often maroon tinted, and branch in the upper portions. Leaves on the flowering stems are small, alternate, linear, not lobed, and lack petioles. Small male and female petal-less flowers are produced in clusters on the tops of separate plants from May to October. Female flowers are red to maroon while male flowers are yellowish-green. A red to maroon fruit (achene) develops from each flower that can remain viable in the soil for 10 to 20 years. The root system consists of a slender fibrous taproot with long rhizomes that grow out in all directions, producing new plants as it goes.
Control: Because of the long viability of the seeds and the roots that produce new shoots, common sorrel can be difficult to manage. The presence of common sorrel suggests that the soil is poor and acid so improving the soil is a good first step to control. Adding manure and other soil amendments such as lime will reduce the common sorrel and encourage more favorable species. This is best done according the recommendations indicated by a soil test (contact your local county extension agent). Hand pulling the weed when the soil is moist several times during the growing season is necessary because of the root sprouting problem associated with common sorrel. Follow up with a thick layer of mulch. For heavy infestations in lawns post emergent herbicides such as dicambra and triclopyr are effective.
Karen Meyers