Common pokeweed (Phytolacca americana L.)
Perennial. Emerges in the spring and flowers from summer through fall. Berries turn black at maturity. Stems and leaves die back in the winter.
Little germination occurs 1 1/2-inches below the soil surface.
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.
Very competitive with field crops in reduced and no-till systems.
Preferred Soil/Field Conditions:
Prefers areas of reduced tillage.
Predation/grazing: No information.
Decay: No information.
Tillage: This weed is effectively controlled by tillage, such as moldboard plowing and disking.
Rotary Hoeing: Not effective.
Crop rotation: Rotations that include tillable row crops can help reduce pokeweed.
Planting date: Most likely will not affect common pokeweed infestations.
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.
Can be an alternate host for soybean cyst nematode.