Common pokeweed (Phytolacca americana) is a perennial weed native of North American. It is frequently found in pastures, as well as fence-rows, row crop fields, and wooded areas.
All parts of the plant contain saponins, oxalates, and the alkaloid toxin phytolacine. The roots and seeds of this species contain the highest concentrations of these compounds.
As winter moves to spring, this plant is emerging from its winter dormancy. The recent warm weather has accelerated the re-growth in north Florida.
Once common pokeweed becomes established, it regrows each year from a large, fleshy taproot. The crown of the root is where the plant is regenerated and can be as large as five and a half inches in diameter at the soil surface within two growing seasons.
Pokeweed usually has a red trunk like stem, which becomes hollow as the plant matures later in the year. Leaves become quite large as the plant grows to its full potential and are the basis for the “poke salad”.
When in bloom the individual flowers appear green to white and are typically missing petals. Fruits are green when immature and turn a deep purple to black at maturity which is the basis for one alternate name for this species, “inkberry”.
Each fruit contains about nine small, hard-shelled seeds. Pokeweed can produce a few thousand seeds to over 48,000 seeds per plant annually.
These seed may remain viable in the soil for over four decades (40 years) under the right conditions. When exposed to the right environmental conditions the seed sprouts and the process is repeated.
While not a suitable selection for people or livestock, birds eat the fruits without much evidence of harm and are usually the means for seed dispersal. Roosting sites along fence rows and under utility lines frequently show signs of seed deposits.
In addition to feed the cardinals, mocking birds, cedar waxwings and other birds, the pokeweed is a host to a variety of insects. Some beneficial and others are not.
A number of caterpillars utilize this weed to sustain their larval stage of development. Unfortunately, some other less desirable insects use the local weed.
Pokeweed can act as reservoirs of various viruses, transmitted by insects and can be destructive to agronomic as well as ornamental plants. Whiteflies and aphids are the main culprits, but other insect species can contribute the disease issue.
Control is achievable by use of some readily available herbicides. The publication Common Pokeweed offers additional information.
To learn more about pokeweed and how to control it, contact the nearest UF/IFAS County Extension Office.