Garlic Mustard - Alliaria petiolata.
Garlic Mustard
Natural History... and a little philosophy
Garlic mustard is one of a thousand species of non-native plants now established in eastern USA, most of which have recently arrived and settled into peaceful co-existence in their respective niches, increasing our local biodiversity. Most often, the victors were the ones who could successfully adapt to the brand new habitat created by our agricultural and industrial practices - open, sunny, disturbed ground. Plant immigration is nothing new - the process is literally as old as the hills. Most of the 2000 native plant species of Ohio, if you go back in time long enough, came from somewhere else, just like most of us did. So what makes garlic mustard so "bad?"
First of all, garlic mustard is not "bad." It is a perfectly well-behaved and community-minded plant at home in the British Isles where it grows in modest numbers along streams and floodplains. However, it is one of many plant species that reached our continent without its assemblage of inter-dependent comrades, species that keep it in balance in its native home such as seed-devouring fungi and beetles. In England, the biennial Garlic mustard is naturally adapted to soils disturbed by flooding, and when it first established itself in the eastern USA's woodlands in the nineteen sixties and seventies, it exploded in numbers.
Above: a garlic mustard feast. Garlic mustard is a delicious green when added
to a number of recipes.
It is easily observed that garlic mustard makes its entry most readily into forests that have suffered some disturbance to the soil, most commonly after a severe logging when the soils have been opened up by logging roads and heavy equipment. Once garlic mustard gets established, it over time sows itself so thickly on the forest floor that our perennial native wildflower species - their populations already highly diminished by human disruption - begin to disappear in its wake.
What can we do?
We have been attending to removing non-native garlic mustard in our preserves for years, but the year 2008 was a major wake-up call, and we have been exceptionally attentive ever since. For the first time, we realized that balance would not occur naturally, and we could actually lose the native understory of our hard-won preserves if we did not remove the plant. Scanning the entire 4000 acre preserve system for colonies of garlic mustard, each with the capacity to grow and spread, is now something we know we must do thoroughly, every single year, without fail.
Volunteer removes garlic mustard in the beautiful
spring woods.
Plucking garlic mustard from our preserves by hand (the surest and most environmentally sound method of removal) is an immense task, one that requires LOTS of volunteer help - a true community of effort - to successfully accomplish. Maybe that's what garlic mustard came here to do for us Americans - to teach us that nothing truly important can be done without effort, and the virtues of community, earnest hard work, and non-procrastination. In regard to the latter, there is only a 10-14 day window in which to effectively act each year to weed garlic mustard - falling at a time when almost everyone is hearing the siren call of their gardens and yards. Regardless, it is a task that can't be deferred to a more convenient time. To successfully remove garlic mustard from any one site requires complete 100% weeding of the species over a span of seven years. After that time, relatively easy maintenance keeps it garlic mustard-free.
Of our 14 preserves, the most severely threatened areas in the Arc of Appalachia Preserve System are undoubtedly the Ohio River Bluffs Preserve on the Ohio River; our oldest and largest preserve, the Highlands Nature Sanctuary where the garlic mustard has gotten a head-start along the canyon floor of the Rocky Fork Creek and several side tributaries; and Spruce Hill which was only recently acquired with a problem already established.
At the Bluffs, although the mustard has taken over a third of this spectacular wildflower-drenched preserve, we managed to reclaim a respectable section of it last spring, helping to save what what just might be one of the best wildflower displays in all of Ohio - and one of the most imperiled. You can tell from the photos this is not a spectacle we should let fall off the face of the earth "sitting down." Quite simply we need a LOT of people to succeed.
Volunteers turn into friends after a successful day. Photo courtesy Catherine Kendall.
There is no use blaming garlic mustard for its fecundity - plants are devoid of malice. Perhaps we could blame ourselves for bringing it over to our country with such a sense of incaution, or for causing so much unprecedented soil erosion in our forests and fields, thereby inviting in a new species to cover our wounds. Or perhaps we could humbly admit that we may be seeing in garlic mustard's "aggression," simply a mirror of our own, since we too are rapidly taking over the world as a single species. Or, perhaps we can choose to blame neither ourselves nor the mustard plant, and simply accept the inevitable impact of our one-world economy on diverse landscapes that have heretofore grown for eons in isolation.
Guilty or innocent, we must accept the reality that collectively our species is sowing the seeds of a new world, and now we must choose with our actions what we want that world to look like. We hope that you will find yourself admiring of garlic mustard's vitality and lime-green radiance. We also hope you choose to weed it, not as an enemy, but with the calm determination of a person who has made a choice for native bio-diversity, and will continue to weed until that day when the garlic mustard finds its natural balance in the new world. And that day shall surely come, because it is the nature of things. Let's hope we learn to do the same!