Wild Leeks welcome us to spring, but need careful harvesting

Following simple rules may not apply when it comes to a springtime favorite.

From Jennifer May for the New York Times

by Steve Gabriel

Anyone who has come across the Ramp, or Wild Leekallium tricoccum, likely can’t help but feel a sense of abundance; these often show up in clusters that can range from a few square feet to a solid quarter acre or more of green. It’s a welcome gift of the forest in this time of year, as the forest wakes up from a long winter’s nap. Ramps are mostly commonly found in the rich, moist soils of deciduous forests. The best patches often occur on North facing slopes and long stream beds.

Other than being a tasty delight, Ramps fulfill an important role as a “spring ephemeral” in the forest. Ephemerals are a class of plants that leaf out before the forest, capturing nutrients and water and holding onto them for several weeks until the rest of the forest comes alive. These plants then die back and offer the trees and other forest plants a dose of food that would otherwise have literally washed away.

Native Range of Ramps

For years I’ve looked forward to harvesting this tasty, tangy, and nutritious plants and felt I could easily harvest a hearty share without inflicting any harm on the population. I used as a guideline the common “2/3 rule”, which suggests that in harvesting one should gather no more than 1/3 of a population to ensure a stable community persists.

But what is this guideline based on? As I thought more about it, the concept sounded nice and simple but I knew better, for plants and ecosystems are rarely able to be summarized in such a way. Further, I imagined an inherent problem with applying a blanket rule to wild plants when I know that the dispersal patterns, regeneration, and regrowth characteristics are vastly different from plant to plant. Some, like ramps, appear to be very fragile by nature, while others, like Stinging Nettle (urtica dioica) is persistent to the point where many consider it a nuisance species. Not me! I love to consume them and they are one of the most nutrient-dense wild foods out there.

A practice I’ve been working at for the past several years is to follow the tracks of hearsay and try to see if I can find research and evidence to support a given claim. The very nature of agroforestry systems is that they operate on longer timescales, demanding careful thought and planning for all activities, whether we are conducting a timber stand improvement, cultivating mushrooms, or wildcrafting edibles.

Backing up ideas with fact is a simple concept, something I hear a lot of talk about in permaculture circles, at my job at Cornell, and as I discuss sustainability in the community. In practice well-researched material seems to often be an afterthought much of the time, so I figured I would look a bit closer at Ramps.Ramp Flowers- http://www.minnesotawildflowers.info/flower/wild-leek

I must give credit to co-author Ken Mudge, whom I’ve been fortunate to work with for many years, for pointing me to some good literature on the subject. The only previous mention I’d seen on the issue of overharvesting Ramps was a New York Times article from a few years ago that mostly asked the question without providing any answers. The first, a 2004 study entitled, “Population recovery of wild leek Allium tricoccum following differential harvesting in the southern Appalachians” cites a startling conclusion after trials harvesting at various intensities over a four year period:

“Harvesting wild leek is not sustainable except at very modest levels. Using the results of this study to predict recovery times, by assuming that growth rates and concomitant recovery times are affected in a consistent manner by levels of harvesting, the sustainable harvest level is predicted to be 10% or less, once every 10 years.”

Another research project comes from the British Ecological Society, who published a 5 year study in Quebec that studied a dense population of Ramps in detail. The conclusion was less dramatic but still highlighted that even a small harvest percentage could have a big impact:

“In a particularly unproductive season like 1985 -86, even a 5% harvest is deleterious, and in all other years a decline is predicted when a 15% harvest is stimulated.”

ramp-seeds: http://www.minnesotawildflowers.info/flower/wild-leek

Many questions remain. It is not only harvest quantity, but also how they are harvested that could make a difference (see this interesting blog post). It might be more sustainable if just the green tops are cut and the bulbs left in the ground. It might be more sustainable if care is taken to harvest the more mature bulbs and leave the young ones. These details we don’t know. What we do know is that a harvest over 10% is likely detrimental, but to be safe aim for a maximum of 5% each year from a given population.

This becomes trickier when harvesting from populations on public lands where multiple people may come through hunting for the ramps. It demands that we take more time to observe, catalog, and note the changes in populations from year to year. And, when in doubt, we should err on the side of caution.

To further reduce stress on wild populations, those interested in ramps should consider cultivation. This factsheet from North Carolina State University is a useful guide for getting started. The eXtension Forest Farming community also produced this excellent set of videos, featuring Jim Chamberlain discussing the ecology, life cycle, and cultivation of ramps through a YouTube series.