Invasive Wild Chervil Blooms Again- Unless You Pull It Up
By Victoria Weber Chervil Correspondent

It is chervil season! I bet almost everyone in central Vermont knows that, but most of us have found excuses for not getting out and working on chervil. I have been amazed at myself for the number of other tasks I have found to do in this very busy season, other than dig out wild chervil.

Wild chervil, or Anthriscus sylvestri,s is the Queen Anne's lace look-alike which is blooming now all along our roadsides and into our fields, woods, yards and pastures. If you have watched it for a few years, you have seen how rapidly it is spreading. There is only one thing to stop, or even slow it, and that is us.

Garlic Mustard, Too

Another thing I have been spending my time on is pulling out garlic mustard, an invasive plant just moving into the Central Vermont area. There is a large patch of it behind the hockey rink in Randolph, a lot near the bridge in Gaysville, and many smaller patches along roads.

It blooms a bit earlier than wild chervil, and is going by now, leaving thin seed pods. So right now is the time to pull garlic mustard to avoid spreading thousands of seeds.

Garlic mustard is about three feet high with straight, unbranched stems, and heart shaped leaves with scalloped edges. Each stalk is topped by a nickel-sized cluster of small bright-white flowers. The visual effect as I drive by a patch is of a bunch of ladders.

I'd estimate that garlic mustard is at the point wild chervil was about 20 years ago. It will spread as rapidly as chervil has, leaving us with a serious infestation within just a few years.

Unlike wild chervil, garlic mustard (Alliaria petiolata) is very well established in many areas of the country, and a lot of research has been done on it. Enough research to know that it moves into woodlands and actually changes the structure of the forest by suppressing the regeneration of the dominant canopy trees. It does this by shading out seedlings and also by inhibiting their growth by negatively affecting the mycorrhizal fungi which aid trees in obtaining nutrients. This is known as an allelopathic effect.

Garlic mustard is simpler to deal with than chervil as it is a true biennial (chervil is a perennial) and it is easy to pull out by just grabbing at the ground level and pulling. The first seeds begin to form in long green pods as the flower clusters begin to bloom. Even if the plant is pulled up, they continue to develop and ripen. Therefore, I take no chances. I stuff the entire plant into a garbage bag and take it to the transfer station to avoid seeds escaping.

Refresher on Wild Chervil

The two things that definitely work to kill wild chervil are weeding it out and smothering it. I weed with a narrow trowel which I first use to loosen the root. Then I grab all the stalks at the ground level and slowly tug the root out of the ground. Just pulling off the top does not do much good, as the root will re-sprout.

Weeding is always easier when the soil is moist, so do it after a rain if you can. I toss small numbers of pulled plants on the dirt road where they quickly disintegrate, and have the added value of advertising that it is possible to take action against invasive plants. Large numbers can be piled up and "poached" under plastic.

Smother chervil by covering it with black plastic, old metal roofing or carpet and weighting them down well. Leave for at least 2 years and then plant something else. This works well on smallish dense plots on fairly even ground.

Cutting does not kill the plants but will keep them from blossoming and spreading their seeds to new areas, so it is worthwhile if you cannot weed or smother. Cut just as flowering begins and again once or twice when it starts to flower again. The more growth the roots have to put out each time, the more likely they are to use up their reserves of carbohydrate. Do NOT mow after seed has set- about June 15 onward, as some will inevitably get into your mower and be moved to new locations.

Information on wild chervil is found at the Wild Chervil Information Center on this newspaper's web site. Go to www.ourherald.com and click on the box at the left under "Services." Information on garlic mustard, and also on chervil, is found at www.IPANE.org, on the Global Invasive Species Initiative web site, and also on the Vermont Master Gardener website.

Invasive Weed Walkabout

Last Saturday a small number of people led by Mike Bald met in Royalton Village for an informal weed walkabout workshop. They examined and identified garlic mustard, wild chervil, swallow wort, buckthorn, Japanese knotweed, honeysuckle and dame's rocket, and discussed control options and experiences.

If you'd like some assistance and advice to get going yourself, contact the Coalition through Lynn McNamara at 728-4422 or lmcnamara@tnc.org.