Pennsylvania Smartweed

Scientific Name: Polygonum pensylvanicum
Family: Polygonaceae


Pennsylvania smartweed is a summer annual. The stems are smooth, reddish purple with swollen nodes, with alternating leaves. The leaves are lanceolate with a red watermark. The growth habit is erect with multiple branching. The flowers of Pennsylvania smartweed are bright pink and bloom from July to October. The individual flowers are small and form dense spike-like clusters on hairy stems. Pennsylvania smartweed is found throughout the United States. 

Cultural Practices

Pennsylvania smartweed may be physically removed. Frequent mowing and improved drainage will also assist in preventing infestation. Use of good turf management programs, including a sound fertilization program, to form dense stands of turf grass may also keep this weed from establishing.

Herbicide Use

Make your post-emergence herbicide application to Pennsylvania smartweed that is actively growing and in the seedling to flower stage of growth.


Germination Dates

3: June
4: June
5: May
6: April-May
7: March
8: March
9: February