Wild parsnip (Pastinaca sativa) is a pervasive and hazardous plant that poses significant risks to human health and native ecosystems. Wild parsnip is a biennial plant belonging to the Apiaceae family, including carrots, parsley, and celery. Native to Eurasia, it has become widespread across North America, often inhabiting roadsides, fields, and disturbed areas. While the roots of cultivated parsnip are edible and nutritious, the wild variant is notorious for its toxic sap, which can cause severe skin reactions.

How to Identify Wild Parsnip

Accurate identification of wild parsnip is crucial for safe management. Below are the key characteristics.

Leaves: Wild parsnip has compound leaves that are pinnate with 5-15 leaflets. The leaflets are toothed and can be up to 6 inches long.
Stems: The plant has a hollow, grooved stem that can reach heights of 4 to 5 feet. The stems are green and may have a slight purple hue.
Flowers: During its second year, wild parsnip produces flat-topped clusters of small, yellow flowers arranged in umbels, each measuring 2 to 6 inches across.
Roots: The plant has a long, thick, white to yellowish taproot resembling the cultivated parsnip.
Growth Pattern: Wild parsnip forms a basal rosette of leaves in its first year and sends up a flowering stalk in its second year.

Life Cycle Of Wild Parsnip

Understanding the life cycle of wild parsnip is essential for effective control.

First Year (Rosette Stage): Wild parsnip seeds germinate in the spring or fall, producing a rosette of leaves that lie close to the ground. During this stage, the plant focuses on root development and energy storage.
Second Year (Flowering Stage): In its second year, the plant sends up a tall, flowering stalk that produces numerous yellow flowers from early to mid-summer. After flowering, the plant sets seed and dies.
Seed Dispersal: Each wild parsnip plant can produce thousands of seeds, which are easily dispersed by wind, water, and human activity. The seeds can remain viable in the soil for several years, contributing to the persistence of infestations.

Dangers Of Wild Parsnip

Wild parsnip poses several dangers, primarily due to its toxic sap.

Phototoxicity: Wild parsnip sap contains chemicals called furanocoumarins, which become activated by sunlight. Skin contact with the sap followed by exposure to UV light can cause a condition known as phytophotodermatitis. This results in severe burns, blistering, and discoloration of the skin, which can persist for several months.
Ecological Impact: Wild parsnips can outcompete native vegetation, reducing biodiversity and altering wildlife habitats. Their aggressive growth can also hinder agricultural productivity and pasture quality.

Preventing & Eradicating Wild Parsnip

Because of the danger wild parsnip poses to people and pets, effective prevention and eradication strategies are essential to manage it.

Prevention

Early Detection: Regularly inspect your lawn and surrounding areas for early signs of wild parsnip. Early detection allows for timely intervention.
Proper Mowing: Maintain a regular mowing schedule to prevent the plant from flowering and setting seed. Ensure mowing equipment is cleaned to avoid spreading seeds.
Healthy Turf Management: Promote a dense and healthy lawn through proper fertilization, irrigation, and mowing practices. Healthy turf can outcompete wild parsnip and other weeds.

Eradication

Manual Removal: Manual removal can be effective for small infestations. Wear protective clothing to prevent skin contact with the sap. Dig out the plants, ensuring you remove the entire taproot to prevent regrowth.
Chemical Control: Herbicides containing glyphosate or 2,4-D can be effective against wild parsnip. For best results, apply herbicides when the plants are in the rosette stage. When using chemicals, follow all label instructions and safety guidelines.
Mowing & Cutting: Repeated mowing or cutting can weaken the plants and reduce seed production. Mow before the plants flower and ensure that mowing equipment is cleaned to prevent seed spread.
Biological Control: No specific biological control agents are widely available for wild parsnip. However, promoting natural plant competition and maintaining ecosystem health can reduce wild parsnip prevalence.

Wild parsnip is a formidable and hazardous plant that requires diligent management to protect human health and maintain healthy ecosystems. Accurate identification, understanding its life cycle, and implementing effective prevention and eradication strategies are crucial for homeowners. Be sure to reach out to the Summit Lawns team for more information on weed control and landscaping in your area!