The Pennsylvania Governor’s Invasive Species Council and partners in the state celebrated the third annual Pennsylvania Native Species Day May 16.

There are several definitions of the term “native plant.” The Pennsylvania Department of Conservation and Natural Resources describes a native plant as one that occurred in the region before settlement by Europeans.

Native plants include ferns, grasses, perennial and annual wildflowers, woody trees, shrubs and vines that covered Penn’s Woods when the first settlers came.

Some examples are garden phlox (Phlox paniculata), bleeding heart (Dicentra eximia), beebalm (Monarda didyma), New England aster (Symphyotrichum novae-angliae), butterfly weed (Asclepias tuberosa), and flowering dogwood (Cornus florida).

There are compelling reasons why you should plant natives in your garden.

Native plants preserve Pennsylvania’s biodiversity.

Biodiversity means the number and variety of living things in a specific region. Native wildlife, especially birds, butterflies, pollinators and other organisms evolved with the plants in the region. Many can only feed on plants they co-evolved with.

Unfortunately, unwise development has led to large expanses of lawn and exotic (nonnative) plants replacing natural areas.

If your garden has no natives, it becomes an ecological desert for the pollinating insects that are essential to human survival.

Insects are needed to pollinate crops. Additionally, native plants are needed to support songbirds by supplying food for the insects that most baby birds require.

Natives provide the habitat (food, cover and places to rear their young) that wildlife needs. Without native plants, wildlife is at risk of extinction.

Native plants are not invasive.

A nonnative plant is one growing outside its natural range. Some exotic plants have become invasive, aggressively spreading into natural areas and threatening native plant communities.

Some native plants are more aggressive than others, but that does not make them invasive. Using regionally and site appropriate native plants reduces the risk of introducing an invasive exotic.

Native plants are generally easier to grow and cheaper to maintain.

While some native plants have exacting requirements and are best enjoyed in the wild, natives are well-adapted to climate and soils because they evolved in a particular area. This means they are generally easier to care for once they are established, needing little or no pruning, deadheading, watering or fertilizing.

Large lawns and showy exotic plants demand high levels of fossil fuel use, fertilizers, pesticides and supplemental water, making natives a less costly option. Site your native plants in a spot that provides the conditions it prefers (soil type, water amounts, sun or shade) and it will thrive.

Purchase from a reputable source.

Do not take native plants from the wild as this is a threat to their populations and a disruption of the ecosystem.

Suggestions on how to use natives.

Integrate them into your perennial borders:

A blending of natives and nonnatives is suitable for many sites.

Naturalize a large area such as a meadow or woodland with more aggressive natives such as sunflowers, asters and black-eyed Susans.

Create a rain garden with natives:

Their root systems stabilize and hold the soil. Choose plants that tolerate fluctuating water levels such as blue flag iris (Iris versicolor), cardinal flower (Lobelia cardinalis), great blue lobelia (Lobelia siphilitica) and blue star (Amsonia tabernaemontana).

Replace unsightly and invasive plants with natives.

Reduce the size of your lawn by adding a bed of native plants.

Educate yourself about plants that are native to the area, then use them in your garden knowing that you are preserving biodiversity, enhancing the livability of your home.

“Growing Green” is contributed by Diane Dorn, Lehigh County Extension Office Staff, and Master Gardeners. Information: Lehigh County Extension Office, 610-391-9840; Northampton County Extension Office, 610-813-6613.