Over the years, a vine has grown up under the aged eave of the tiny frame house to form a large ball of dead leaves and branches. Facing east, it catches the morning sun, but by afternoon is in the shade. Most of the time, it is chock-full of sparrows — flitting, chirping and dropping down into the jumble of garden below. It is a joy to see and hear.
Being on that side of the building and under the eave, the vine is protected from cold winter winds by the building and from the snow and rain by the eave. With the sunshine and access to the garden, it makes a perfect habitat.
We know that urban areas, particularly suburbs with lawns, trees and gardens, make excellent habitat for many birds. Wildlife scientist, John Marzluff reported that bird diversity was greatest in the suburbs, in spite of high predation by domestic cats.
So, besides bird feeders, why are suburbs good for birds?
It seems that like people, birds favor places with diverse vegetation. Certainly, a tree canopy provides safety from predators, protection from weather, and roosting and nesting sites. Shrubbery is also an attraction for many of the same reasons, as a lot of birds prefer the lower tiers closer to the ground, and the denser vegetation for additional shelter. Birds also prefer some open, grassy areas, as well as flower and garden beds, for foraging on seeds and insects. Lastly, developed areas provide access to a wide variety of water sources, including gutters in the streets and on buildings, backyard ponds and pet watering stations, and irrigated lawns and gardens.
A suburban lot commonly has trees planted around its boundary. Shrubs are placed under and inside the tree line, then come the flower and garden beds surrounding the lawn. This cascade effect is perfectly suited for birds, providing transitions between vegetative stages. Tiering the plantings is good for more than wildlife, too.
Once, in Alaska, we went wild blueberry picking on a densely forested hillside. At the time, I was surprised, since I had understood sunlight to be critical to growing good things to eat. However, it turns out some wild plants prefer to grow in shade. So it is possible to develop agricultural operations using the tiered approach, too.
American writer, Brian Barth, reports, “Forest gardening has been the standard for millennia in many tropical regions, but it’s possible in more temperate climes as well. … I’ve seen it time and time again in my travels throughout Latin America — towering mango trees leaning over patches of banana and papaya, interspersed with little plantings of cassava here and there, perhaps a passion fruit vine snaking through it all.”
Forest gardening is becoming more popular as people consider permaculture and edible landscaping, not to mention fostering habitats more supportive of wildlife. The concept, according to Barth, consists of seven layers:
• Canopy trees requiring full sun throughout the day, like nut trees.
• Understory trees such as smaller nut trees and the majority of fruit trees.
• Fruiting vines and shrubs.
• Herbaceous plants, such as herbs and perennial vegetables.
• Groundcovers, some of which are edible.
• Rhizosphere, root crops.
Barth goes on, “Food forests are like the ultimate organic garden. Does a forest need tilling, weeding, fertilizer, or irrigation? Nope. And that’s the goal … Because they’re mostly perennial crops, there’s no need to till. Not tilling preserves the natural soil structure, preventing the loss of topsoil and allowing all the little microbes and soil critters to do their jobs, cycling nutrients and maintaining fertility. The deep roots of trees and shrubs make them much more drought tolerant than annual vegetables, and they shade the smaller plants below, keeping everything lush and moist in a self-maintaining — in other words, a highly sustainable — system.”
Interestingly, our lot already has many of the attributes of the forest garden. Many of our shrubs and vines are either native or were selected for their wildlife attractions. The boundary trees pre-existed our occupation, but we added a couple for habitat or fruit. Our vegetable garden, flower beds and lawn are suitably chaotic and pleasing to us as well as to birds and insects.
Maybe forest gardening is somewhat innate. Maybe it reflects some primordial urge to fit into nature, rather than battle with it. Maybe it harkens back to a time when man lived on the land and was a part of it.
Wouldn’t that be nice.
Brian Barth, How to Plant a Food Forest This Winter, February 8, 2017, Modern Farmer
John Marzluff, Subirdia, 2014