Department of Plant, Soil and Microbial Sciences Weeds

Common pokeweed (Phytolacca americana L.)

Life Cycle:

Perennial. Emerges in the spring and flowers from summer through fall. Berries turn black at maturity. Stems and leaves die back in the winter.

Emergence:

Little germination occurs 1 1/2-inches below the soil surface.

Reproduction:

Mode(s) of Reproduction: Reproduces by seed. Plants resprout from taproots.

Dispersal Mechanisms: Birds eat pokeweed berries, the seeds survive digestion, and are redeposited to create new infestations.

Longevity: Pokeweed seeds can remain viable in the seed bank for up to 40 years.

Dormancy: Some seed can germinate immediately after dispersal if exposed to light, however over-wintering (i.e. stratification) increases the germination speed and the number of seeds that will germinate. Over-wintering is required for seed to germinate in the dark.

Competitiveness:

Very competitive with field crops in reduced and no-till systems.

Preferred Soil/Field Conditions:

Prefers areas of reduced tillage.

Management:

Biological

Predation/grazing: No information.

Decay: No information.

Mechanical

Tillage: This weed is effectively controlled by tillage, such as moldboard plowing and disking.

Rotary Hoeing: Not effective.

Flaming:

No information.

Cultural

Crop rotation: Rotations that include tillable row crops can help reduce pokeweed.

Planting date: Most likely will not affect common pokeweed infestations.

Chemical

Application timing and effectiveness: S Seedlings are readily controlled by residual herbicides. Established plants are most susceptible to herbicides when they are between 8- and 12-inches tall. Sequential herbicide applications may be necessary for control. Please refer to E-434, "MSU Weed Control Guide for Field Crops," for herbicide recommendations.

Additional Information

Can be an alternate host for soybean cyst nematode.