by guest blogger Kristina Jones, director of the Botanic Gardens at Wellesley College
When I was a kid, my neighbor had an ancient green plum tree with branches that reached over the fence into our yard, laden with the sweetest fruit. This tree is one of my favorite memories of the neighborhood. Fruit trees are some of the most appealing things you can grow, so why aren't more neighborhoods dotted with peach, cherry, pear, and green plum trees (the fruit-bearing kind, not the ones that flower to no avail)?
Unfortunately, most fruit trees are high-maintenance, requiring lots of attention to meet their needs for soil nutrients, water, and pest and disease control, so we tend to douse them with synthetic chemicals and shower them with drinking water. But there is another option: You can set up a biological community to support the needs of the trees so that your main job is just to harvest the fruit.
The idea behind an "edible ecosystem" garden is a different but complementary approach to organic farming. Rather than make a traditional agricultural operation more ecologically sound by using organic methods, the edible ecosystem approach mimics a natural ecological system but swaps in food plants so that the system is particularly productive for humans--although you may still need to outsmart the birds and other creatures also interested in the fruit!
In New England the model ecosystem is a forest. Nobody fertilizes the forest or sprays pesticides, but most years the oaks still make gazillions of acorns. The key to gardening like a forest (and to setting your fruit trees up for success) is to select plants that are both well adapted to existing conditions and serve the various functions needed by the fruit trees. For example, deep-rooted plants like comfrey serve as elevators for nutrients, bringing phosphorus and potassium from deep in the soil up into their own leaves, which then serve as nutritious mulch for the tree, and nitrogen-fixing plants such as legumes enrich the soil, as well. And choosing plants with root structures that are different from the fruit tree's helps minimize competition for nutrients and water.
Yarrow and coreopsis, which have many small flowers over a long blooming season, attract and retain beneficial insects in the community. Have you ever released ladybugs to control aphids? When the aphids are gone the ladybugs leave, too, unless there's an alternative food source available; pollen serves that function well. Herbs and other strongly scented plants may serve as "aromatic pest confusers" for everything from beetles to deer.
While some plants serve several of these functions, it's a good idea to have a diversity of species performing the various roles so that the community/garden is most resilient in the face of challenges like drought or disease.
This is clearly a knowledge-intensive approach to gardening, so it is fortunate that there are lots of good resources out there to help. At Wellesley College, we are working with permaculture experts Dave Jacke and Keith Zaltzberg to implement an edible ecosystem garden that includes a nut grove, fruit thickets, a fruit woodland, and an edible meadow (or "eddow") in less than half an acre within the campus botanic gardens. Dave and Keith have connected us to the permaculture community and to resources such as the amazing Edible Forest Gardens books and the Apios Institute, which builds and supports communities of amateur and professional practitioners to research and demonstrate agricultural ecosystems modeled on the structure, function, and dynamics of temperate climate forests.
We are studying the garden at Wellesley as it evolves, taking data on everything from pest damage to yields. The garden is only in its second year, so our yields so far have been understory plants like mint and chives. We've also been able to make anecdotal observations like noting the baby nut trees that had chives nearby have had less browse damage than those without chives as neighbors. As more and more people implement permaculture gardens, the knowledge base supporting this approach will grow.
Healthy ecosystems really do provide the services that species require, even high-maintenance ones like fruit trees (or humans). Assemble a highly functional, self-sufficient community in your own garden--and reap the rewards!
Kristina Jones is the director of the Botanic Gardens and assistant professor of biological sciences at Wellesley College. She is interested in plant-animal interactions, particularly pollination and herbivory, and ecological approaches to growing food.
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