Wild chervil (Anthriscus sylvestris) is a troublesome weed in some regions that has invaded roadsides and other non-crop lands, pastures, wood edges and open woods with rich soils. It resembles other members of the carrot family, so can remain undetected until it becomes an issue. In stands it grows 30 cm tall to 1.5 m tall and looks similar to wild carrot, although wild carrot does not usually form such extensive, dense patches. Once patches of wild chervil are established, the plants will spread aggressively and can be very difficult to eradicate. It will choke out desirable vegetation and native plant communities, reducing wildlife habitat.
Wild chervil is a biennial or short-lived perennial that spreads by seed and by budding at the base. The seed spreads easily by birds, humans, mechanical equipment, recreational vehicles and water. A basal rosette of fern-like leaves grows the first year. The plants develop a tap root that grows up to 1.8 m deep. Flowers form in the second or later years in panicles of umbels with five small white petals.
// What to look for
Some key characteristics to differentiate wild chervil from other species:
• Wild chervil flowers very early compared to other look-alikes, in late May and finishing by early June. Wild carrot does not start flowering until June and continues flowering until September.
• Wild chervil has compound fern-like leaves that clasp the stem at the base and have hollow, distinctively ridged stems. Wild carrot has more finely divided leaflets that smell like carrot when crushed.
• Wild chervil seeds are smooth and turn green to dark brown. In contrast, wild carrot seeds have rows of hooked spines and often remain in bird’s nest-shaped clusters on the wild carrot plants.
Wild chervil is a host for a virus that infects carrots, parsnips and celery.
// Bayer Solutions
Apply herbicides early, shortly before blooming or a month after pre-bloom cutting.
Applying Navius or Truvist to small chervil plants – preferably when they are 10 - 15 cm tall – can improve control. If chervil plants are taller than 15 cm, or for heavy infestations, effective control requires complete spray coverage of the foliage. Use application equipment that gives the best coverage of all chervil plants while minimizing spray drift. Remember, taller plants, railroad ties, guardrails and other obstacles can shield or shadow smaller plants and limit contact with shorter chervil plants that are targeted for control.
Late summer and fall control of wild chervil rosettes is effective as long as the plants are still green and will prevent seed production the following year. In late summer and fall, photosynthates are moving to the root, which is an advantage for root control with many foliar herbicides. The benefit of using herbicides with residual control is to prevent germination of seedlings after treatment.
Cleaning equipment after a herbicide application to a site, after mowing, ditching or any other work on infested sites will help to prevent linear spread down rights-of-way. For cleaning protocols for contractors: https://www.ontarioinvasiveplants.ca/wp-content/uploads/2016/07/Clean-Equipment-Protocol_June2016_D3_WEB-1.pdf
After control, establishment of competitive cover is important to prevent new infestations.