Key Facts
- A biennial plant that typically flowers in its second year
- Shows flat topped clusters of yellow umbrella shaped flowers
- Contains a sap that can cause severe phototoxic skin reactions
- Spreads primarily by seed and can form dense stands in disturbed areas
- Native to Eurasia and considered invasive in parts of North America
- Often found along roadsides fields and other disturbed sites
- Has a deep taproot that makes mechanical removal difficult
Wild Parsnip is a biennial weed many gardeners encounter in fields and along roadsides. The plant spreads easily by seed and its sap can cause severe skin burns when exposed to sunlight.
Identification
Wild Parsnip produces flat topped clusters of yellow umbrella shaped flowers in mid to late summer. In its flowering year plants typically reach about 20 to 59 inches (50 to 150 cm) tall. Leaves form a basal rosette the first year and a tall flowering stem in the second year.
Where it grows and why it matters
Native to Eurasia Wild Parsnip is considered invasive in parts of North America. It commonly colonizes disturbed ground such as roadsides field edges and pastures. It tolerates a wide range of soils but prefers well drained fertile ground and does best in full sun to partial shade.
Lifecycle and spread
Wild Parsnip is a biennial that typically flowers in its second year. Plants reproduce mainly by seed and can form dense stands. An individual mature plant often occupies about 12 to 36 inches (30 to 90 cm) across so populations can expand quickly where seed is allowed to set.
Safety when handling
The plant produces a sap containing furanocoumarins that cause phytophotodermatitis. Contact with sap followed by sunlight can produce painful blisters and long lasting skin discoloration. Avoid touching leaves stems and sap. If you must work near plants wear long sleeves long pants gloves and eye protection and wash exposed skin promptly.
Control and removal
Because Wild Parsnip has a deep taproot mechanical removal can be difficult. Management focuses on preventing seed production and protecting people during control work. Mow or cut plants before they flower to reduce seed set and remove flowering heads carefully using protective gear.
Collect seed heads in bags and follow local disposal guidance. Do not compost seed heads where seeds can survive. If you plan physical removal dig out the root crown but expect regrowth from deep roots in some sites.
Watering and site conditions
Wild Parsnip prefers well drained soils and tolerates poorer and drier conditions. It establishes readily in disturbed soils and open sunny sites. Shading can reduce flowering and seed production but will not reliably eliminate plants.
After flowering care
Remove seed heads before seeds mature. Repeat monitoring in following seasons because plants reproduce by seed and seedlings will appear near parent plants. Treat new rosettes early when they are easier to remove.
Frequently asked questions
How fast does Wild Parsnip grow? Wild Parsnip typically forms a rosette the first year and produces a tall flowering stem in the second year. Mature flowering plants can reach multiple feet in a single season.
Is Wild Parsnip better grown indoors or outdoors? Wild Parsnip is an outdoor biennial and is not suitable for containers or indoor growing. It is considered invasive in many areas and should not be cultivated in home gardens.
How dangerous is the sap to people and pets? The sap is phototoxic and can cause severe skin irritation and blistering when skin is exposed to sunlight. Exercise caution with children pets and pets that may come into contact with plants and consult local poison control for pet exposure concerns.
Will mowing stop Wild Parsnip? Mowing before flowering can reduce seed production. Repeated mowing or cutting may help control patches but will not remove deep roots. Monitor and remove new plants that sprout from seed.
Can I compost plants I remove? Do not compost flowering heads or seeds. Bag and dispose or follow local waste guidelines to avoid spreading seed.