Biodiversity Gardens

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Land in temperate climates supports various gardens such as ornamental flowers, vegetables, herbs, or cacti. A biodiversity garden acts as another specialized type of garden that helps maintain diversity in nature. Biodiversity gardens contain plants selected to provide habitat, shelter, or feeding for reptiles, amphibians, insects, birds, small mammals, and even invertebrates and microbes. In some urban neighborhoods these gardens may present one of the few places where a healthy ecosystem can function.

In addition to providing for native plant and animal life, biodiversity gardens can serve a role in rescuing plant species that are slipping toward extinction. Two hundred years ago farmers grew a large variety of vegetable plants and fruit trees, but over time commercial farms reduced the number of varieties to make packing and shipping easier. Growers prefer plant and fruit varieties that mature quickly, resist bruising during shipping, and have a long shelf life. In the process of targeting these traits, many thousands of other varieties have become increasingly rare. The Public Broadcasting System (PBS) reported in 1998 that to save plants with a long history in North America, called heirloom varieties, “an increasing number of dedicated gardeners are growing these threatened plants and sharing the seeds with others. These ‘seed savers’ have rescued hundreds of varieties . . .” The naturalist Craig Tufts of the National Wildlife Federation explained in the PBS show, “When people open their eyes, they can be amazed at what they can find in their own backyards.” Biodiversity gardens offer an excellent way for a household to observe nature.

Planning and building a biodiversity garden adheres to the following steps:

1. Explore local open space and determine the types of bushes, shrubs, and plants that grow there.
2. Seek a natural location to plant the garden in a place where it will attract wildlife—near ponds, streams, meadows.
3. Plan vertically as well as horizontally by selecting climbing plants such as ivy or creepers or small trees and build a trellis if needed.
4. Provide water in a ground-level space and also in a raised birdbath.
5. Include plantings that provide hiding places for birds, reptiles, and small mammals.
6. Substitute organic fertilizers for chemical fertilizers and eliminate use of chemical pesticides.
7. Install raised nest boxes for birds and install nearby bat boxes.
8. Minimize trimming and clipping, but water often.

 The Royal Horticultural Society headquartered in London, England, suggests that the best way to assess whether a garden contributes to biodiversity is by watching for birds, bees, and butterflies. Birds indicate that the garden offers nectar, pollen, seeds, and insects and may possibly provide adequate nesting space for a new family of hatchlings. Birds also supply a food source for foxes and hawks. Birds and bats additionally act as effective insect pest control. Honeybees and bumblebees indicate that flowering plants and trees are breeding and producing pollen and nectar. The presence of other insects such as hoverflies and ladybugs indicates that pest control is working because these species eat harmful insects such as aphids. Butterflies contribute to the garden ecosystem because their larvae provide a protein source for birds, small mammals, and other insects.

 A good rule of thumb in answering the question of how well a biodiversity garden helps nature is to watch or listen for a variety of insect, reptile, amphibian, bird, and mammal life. Daytime and nighttime activity by a wide variety of species assures that the diverse plantings have successfully provided a space for nature to thrive.