By Ruth Ann hales, Colorado State University Cooperative Extension agent, horticulture
The healthiest landscapes are those with the greatest variety of plants.
Gardens in balance with nature usually contain several kinds of monocots (grasses) and a wide variety of dicots (broad-leafed plants).
Monocots include the Kentucky bluegrass in your lawn, lilies and iris in flower gardens and chives in the herb garden. Dicots include lilac shrubs, ash trees and petunias, as well as the many other broad-leafed plants that add diversity to your yard.
Why is diversity important? Each plant is host to various good bugs and bad bugs. If your yard contains only a few species, those plants are vulnerable to an insect infestation. If, however, your yard contains a wide variety of species, there's much less chance that any one insect will damage the entire landscape. As well as living harmoniously with certain insects, different plants also attract different diseases. Some plants actually keep certain diseases away.
Yards with only three or four different types of plants lack biodiversity. This lack creates imbalances in pest populations that can lead to unnaturally large populations. When pest populations become large, the need for chemical controls increases. Increasing plant diversity is the most environmentally safe alternative to chemical control.
It's easy to determine the extent of your yard's biodiversity. Just count the number of different trees, shrubs and grasses. Count the flowers and herbs. The higher the count, the greater chance that the ecosystem within your yard will be a balanced one.
Photo: Judy Sedbrook
© CSU/Denver County Extension Master Gardener 2010
888 E. Iliff Avenue, Denver, CO 80210
Date last revised: 01/05/2010