It often doesn’t occur to people that the beautiful shrub they planted last spring could be a major driver of habitat and wildlife loss. By crowding out native plants and wildlife, invasive plants, together with other invasive species, are the second greatest threat to global biodiversity after outright habitat destruction. They can increase wildfire risk—changing the natural-fire regime by increasing the frequency and intensity of wildfires. They also exacerbate floods and droughts.
A 2009 fire in California’s Angeles National Forest, for example, was exacerbated by Spanish broom, a highly flammable, plant that covers much of the surrounding mountains. Farther north, in the Port of Stockton, invasive water hyacinth has blanketed waterways, depriving aquatic life sunlight and oxygen, clogging harbors in the Sacramento-San Joaquin Delta, and making the rivers impassable to boats.
Controlling invasive plants is also expensive. Countries throughout the world are vulnerable to the costly damage of invasive plant species. Australia, for example, spends approximately $1.5 billion on eradication efforts and estimates agricultural crop losses of $2.5 billion each year. California spends more than $80 million each year just trying to manage and control invasive plants. Nationally the management costs are estimated to be in the billions.
As climate change amplifies the impacts of invasive species, finding ways to reduce the number of invasive plants people can buy is more important than ever. Unlike most pollutants that stress our land, air, and waterways, this botanical, biological litter adds insult to injury by self-populating. In the United States, according to the US Forest Service, invasive plants are spreading at a rate of 1.7 million acres per year. Lucky for us, preventing new ornamental invasive plants represents an avoidable problem with big cost savings (economically and environmentally). At the risk of mixing metaphors, using exclusively non-invasive plants (exotic or native) is also a low-hanging-fruit solution in a complex landscape of daunting environmental problems.
When our California-based organization, Sustainable Conservation, learned that 50 percent of the invasive plants in the U.S. were introduced through gardening, we set out to engage the gardening and nursery industry in solving the problem, starting in our own backyard. Many entities and individuals influence the sale of garden plants— landscape architects and designers, nursery retailers, plant breeders, botanical gardens, and people who write about gardens—so no one organization or even several organizations could fully address this issue on their own. Finding a solution required that we bring together leaders from the various constituencies that influence plant purchases, along with environmental organizations and government agencies that understand the serious environmental and social impacts invasive plants have. We crafted an approach that centers on building collective buy-in around a common goal, and then devised strategies to realize that goal in partnership with all who were affected by the problem.
Catalyzing the PlantRight Network
After thoroughly researching how the horticultural market works and learning who its leaders were, our first step was to gain the nursery industry’s partnership in addressing the issue. We began by organizing a one-day workshop in 2004, to which we invited stakeholders from all industry segments—including national representatives—that influenced the sale of plants.
At the workshop, we shared the results of credible surveys conducted in California showing that virtually all nurseries were selling one or more invasive plants, and engaged scientific experts who explained the negative impact of invasive plants. We then presented some possible approaches to stopping the sale of invasive plants, and asked whether the representatives present would like to work collectively and collaboratively to address the issue.
The group was enthusiastic about working together and over the course of the next year, we met regularly to establish a common understanding of the problem and the nursery industry through in-person meetings and field visits to both a plant invasion site and a nursery facility. We encouraged deep listening and understanding of diverse perspectives, which built trust and led to agreement on strategies. The group decided to call the alliance that came out of this process PlantRight.
We proceeded to meet quarterly, and have since designed and guided PlantRight to prevent the sale of invasive plants in California and promote non-invasive alternatives to minimize the economic impact on nurseries. This has required that network members agree on—based on scientific evidence—what plants are invasive and inappropriate to sell, which alternative species should be promoted instead, what criteria should be used for removing plants from the PlantRight list after they are no longer commonly sold, and what criteria should be used for adding new plants as information becomes available. Sustainable Conservation’s role has been to provide the platform, resources, facilitation, guidance, and recognition for stakeholder commitment.
The Viral Effect of a Network Approach
The beauty of gaining buy-in for a collective goal is that the most effective messengers—trusted industry leaders beyond the walls of our own organization—are advocating on behalf of PlantRight to their colleagues. The prominent national ornamental plant grower Altman Plants, for example, introduced PlantRight to The Home Depot buyers and helped secure The Home Depot’s commitment to not sell invasive plants in California. That commitment has played an important role in the 60-percent decline of big-box stores selling an invasive plant in California over the past year.
The results of PlantRight in California have been impressive. Measured by an annual survey of a randomly selected and statistically significant number of nurseries, sales of the original 19 species on the PlantRight list have decreased dramatically. 100 percent of nurseries offered one or more invasive plants in 2004, and as of this year, only 13 percent do. And recently added invasive plants decreased from 40 percent to 30 percent over the past year.
Sustainable Conservation is now working to broaden the PlantRight network as we seek our ultimate goal: preventing the introduction of invasive plants to the horticulture market in the first place. To do this, we have created a new, national coalition to guide the deployment of a scientific tool that has a 95 percent accuracy rate in predicting invasive behavior risk in a given region. The coalition will encourage the nursery industry to adopt the tool.
Involving stakeholders from across the whole system, from the beginning, has not only better informed our strategy, but also enabled diverse groups to embrace the outcome—importantly, without the feeling of winners and losers that results from a more adversarial approach. In addition, our partners have helped extend the commitment to keep invasive plants out of the nursery trade by opening doors and lending a sense of credibility to our efforts that would have taken us far longer to achieve on our own. As the network expands, we believe that not selling invasive plants will become business as usual.