Practice No. 8. Diversification
Diversification is a practice foreign to today's modern landscape. We tend to view landscapes as an extension of the interior decoration of the home – exterior decoration where the number of plant species is limited for visual effect. Garden rooms – outdoor spaces that mirror and extend indoor rooms – is the catch phrase for modern garden design.
This present day image of garden design is often in conflict with nature. The landscape is a dynamic system, not static, captured in a photo or still life painting. “By viewing our landscapes as dynamic ecosystems, rather than as static collections of inert objects, we can create gardens that inherently grow in healthy patterns and directions. This perspective lets us transfer much of the labor of maintaining our yards to nature,” (Hemenway, Toby, Gaia's Garden, A Guide to Home-Scale Permaculture, Chelsea Green, 2nd Edition, 2009).
Diversification refers to growing a large number of mutually benefiting plant species within the landscape. It is estimated that there are between 250,000 – 280,000 species of flowering plants (angiosperms). Of the approximately quarter million possible species, there are quite a few hundreds that grow exceedingly well in the Texas Panhandle. Diversification doesn't mean helter-skelter planting of a hundred different plants, but rather thoughtful, purposeful selection.
Build Plant Communities
One of the best methods of diversification is in building plant communities – groupings of trees, shrubs, herbaceous perennials, grasses and annuals together, mimicking native plant communities. The communities, often referred to as guilds, need not be composed entirely of natives. Non-native plants are intricately woven into our lives (food crops in particular) and don't need to be excluded, however native plants contribute to the native ecology. Natives and non-natives planted together provide shade, protect from the wind, build soil, provide habitat, nesting and food sources that attract beneficial life, from soil organisms all the way up to larger mammals. Nature, unaided or interfered by man, works.
Creating plant communities is artificial compared to nature itself, but is preferred to the present sterile landscapes. The absence of diversity is one factor that makes monocultural lawns and garden ornamentals highly susceptible to pest and pathogen attack. Today's traditional monocultures are abnormal, not only because of single plantings, but because of the gardening practices used to sustain them. Additionally, when so few plant species are planted city block after city street, links in the food chain are weakened or absent. Expanses of single or a few unfruitful hybrid plants make it easier for herbivores to pinpoint their next meal. Without the diversity of beneficial organisms to protect plants, predators move in to feast.
A diversity of plants create many different habitats for beneficial microorganisms, insects and animals. Pollinator friendly plants draw beneficial insects into your garden. Gardens composed of plants with a variety of flower shapes, colors, and consecutive flowering seasons appeal to many different insect species with different roles in plant protection and health. Limit sterile, pollen-less hybrids these pollinators cannot use. To enjoy a landscape filled with nesting birds, there must be insects. To have insects, there must be flowers they can use. If we want birds in our landscape to eat mosquitos, we need to provide the environment they need to survive. We and they are not mutually exclusive.
Provide a Safe Haven
Stopping the kill-off of beneficial organisms is half the equation. The other half is keeping them, providing food, water and shelter. Your neighbors may not switch to an ecologically-friendly method of gardening and continue with pesticide use. Those lone survivors (butterflies, birds, bats, toads, beneficial insects) of neighborhood chemical warfare will need a place to relocate to. Non-hybrid, native annuals and perennials act as flags and billboards drawing beneficial's into your garden. Capitalize on the exodus from chemically ravaged landscapes.
Stable ecological environments have a great many plant and animal species. The more complex the diversity of life, the more numerous and varied are the interactions between and among them. "Biological diversity increases biological complexity, which increases biological stability (or balance) . . . Balance is what happens when nature is in harmony with itself." (Grissell, Eric, Insects and Gardens, In Pursuit of a Garden Ecology, Timber Press, 2001). This is good for the health of your garden, enhancing beauty while reducing maintenance.