Published in the Contra Costa Times on June 24, 2006

Q. I live in Walnut Creek near the edge of town, adjacent to Mt. Diablo State Park. About two to three years ago I noticed that my dogs and I were picking up these small, very sticky burrs when walking in the park. I subsequently realized they were the end result of small white flowers on a delicate small bush. When very young sprouts they resemble fern-like carrot leaves; when flowering they look very much like “baby’s breath”, but the burrs are so pervasive that I have had to throw out socks and T-shirts because I literally could not removed them from the knit fabric. This spring I notice they are spreading dramatically – thick and fast. They have virtually blanketed a school’s nature study area next to me and I see them all along roads and streets nearby. They seem like they could become really threatening to yards and gardens and will obviously continue to be spread by animals.

A. The pretty plant you are describing is called by several names. The botanical name is Anthriscus caucalis in the Apiaceae family. Carrots are members of this family also.

The common names include Bur Chervil and several others, unprintable. It is a weedy plant found in disturbed places at low elevations. It is native to the British Isles and prefers a moist environment. Currently it can be found from Washington to central California. In its native habitat it is described as rare. Although the plant appears delicate, the dainty white flower clusters can produce more than 2,000 viable seeds per plant. The seeds mature between 10 and 12 weeks after the flowers appear, and are covered with Velcro-like hooks that attach precipitately to animal fur, socks, shoe laces and clothing. They are extremely difficult to remove.

The wet winters we have enjoyed for the past few years have provided the perfect environment for Anthriscus and it has spread rapidly. Pulling the plants out when you notice them is your best line of defense. Do not let hem go to seed. This is an annual, and, if you can prevent the seeds from establishing, you will make your gardening life easier. There are reports of Anthriscus becoming as a lawn weed in some areas. Hand pulling as soon as it is noticed can provide effective control. In areas where you walk dogs, cut back the plants before the seed heads mature.