Garlic Mustard Challenge

The Challenge Of Garlic Mustard
Along The C&O Canal

March 2016

The invasive garlic mustard plant is advancing rapidly into the C&O Canal National Historical Park, as it is elsewhere in this region. The growing banks of garlic mustard visible along the towpath and throughout the park are endangering the ecology of native plants and animals. The canal park staff is asking for help from volunteers to meet the Garlic Mustard Challenge (GMC) and join the effort to stem the influx of the plant into the park (no pun intended).

Garlic Mustard

The C&O Canal Association formally accepted the challenge and calls upon our members to join a long battle against the plant's spread. It will require a commitment of at least five years to be effective in eradicating this plant from any identified area. What exactly is the challenge and what should we do to meet it?

Garlic mustard (alliaria petiolata) is a classic alien, nonnative invasive plant. It is not easy to eradicate and can overwhelm the habitats upon which plants, and even animal life, native to an area depend.

What are the plant's distinguishing characteristics?

• Fast growth is its hallmark. It grows in shade or sun and can cross-pollinate or self-pollinate. It is a biennial and in its second year each plant sends out hundreds of seeds. It can soon take over a site and produce seed banks generating thousands upon thousands of seeds.
• The second-year plant generally appears in early April and goes to seed beginning in late May and June. Once seeds are sown, they may lay dormant for 2-3 years before sprouting.
• The plants can quickly monopolize a site and, remarkably, produce chemicals curbing the growth of other plants and even native fungi that help the growth of tree seedlings.

Ridding the park of garlic mustard is no easy task. In order to develop an effective action plan:

• We will be working very closely with the park staff.
• We will provide necessary training for dealing with garlic mustard and its surroundings.
• We need to identify specific areas of the park where garlic mustard has taken hold.
• We then need to get our members to either adopt one of these areas or be ready to help others who have adopted an area.

The garlic mustard must be removed each year for at least five years to produce good results. It is envisioned that over the next few years responsibility for a site or area can change hands. The most important thing is consistent removal of all second year growth each year. We encourage all of our members to get involved.

If you know of an area that has been invaded by garlic mustard, let us know the location. The park service MUST approve each site/area. If there are endangered native plants in that area, special procedures need to be put into place to protect them.

It is of utmost importance that the general public realize this is not an activity that anyone can do without training AND approval from the C&O Canal park staff. We want to advance the quality of our park, not to do damage to it through limited understanding.

To get more information about garlic mustard, check internet websites for garlic mustard. A number of sites contain information on how to control its spread. Some of the sites present a variety of garlic mustard recipes for this edible plant. Although removing garlic mustard is not difficult, perseverance in the task is the key to success.

The Association continues to conduct the Garlic Mustard Challenge (GMC) and will offer hands-on training sessions for new volunteers as the need arises. If you are interested in participating in the program please contact Jim Heins or Steve Dean at gmc@candocanal.org