Urban Jungle

April 16, 2013

Garlic mustard: Salad days for an invasive plant

In April, garlic mustard begins its rampant growth in local woodlands. Should you join a group organized to remove the invasive plant, you will inevitably hear about the recipes: pesto, soups, roulade, frittatas, vinaigrettes.

It only takes a few plants to make a meal, but during a weed pull, tens of thousands are yanked from the ground, bagged and sent to the landfill.

Despite its tasty potential, garlic mustard is an unwelcome colonist that overwhelms native herbs. Although the mechanism isn't fully understood, the presence of garlic mustard inhibits the soil fungi that many other plants rely on for growth — fungi of which garlic mustard has no need.

An absence of natural insect predators might also be giving the weed an edge. (Even deer won't eat it.) But if an animal does take a nibble, it may find itself chewing on an array of bitter chemicals.

Don Cipollini, a Wright State University professor of plant physiology and chemical ecology, discovered a few years ago that, unlike most other plants in the mustard family, young garlic mustard leaves contain significant amounts of cyanide.

That could be "concerning for mammals," Cipollini said, "if large amounts of fresh leaves were ingested" or eaten "chronically, like a salad of fresh garlic mustard every day," which would be difficult to do: "The leaves are awfully bitter eaten fresh," Cipollini said.

But "cooking would greatly reduce or eliminate cyanide levels," he said, pointing out that lima beans also harbor cyanide and need to be cooked before consumption.

Garlic mustard has a two-year life cycle. The first year is spent as a small rosette of leaves close to the ground. In the spring of year two, the plant bolts, sending out big leaves and a stalk topped with small, four-petaled flowers.

Cipollini found that levels of bitter chemical compounds are lower in the leaves of second-year plants than in those of first-year plants. "At that point in their life cycle," Cipollini said, "the plants are devoting a great deal of resources toward reproduction, rather than defense." Although Cipollini doesn't recommend a daily garlic mustard salad, "eating it on occasion, and in items like pesto, should be harmless if not even beneficial."

A 2007 study of the nutritional composition of the herb revealed that garlic mustard is high in Vitamin C, carotenoids and minerals, and it has remarkably high levels of fiber.

So, eat up.

QUICK GARLIC MUSTARD SAUTE

♦  In a shallow pan, saute a chopped garlic clove in a tablespoon of olive oil.

♦  Add a handful of loosely chopped garlic mustard leaves and a tablespoon
   of water to the pan.

♦  Cover pan on low heat for 5 minutes.

♦  Remove cover and add a dash of balsamic vinegar.

♦  Cook uncovered for a few more minutes or until leaves have fully
   collapsed.