Ecological value of native plants

Barb Mrgich
Adams County Master Gardener

(3/17) Native plants are generally defined as the plants that were growing in our area before the arrival of the European settlers. Not everyone agrees as to whether that plant should be a species plant or a cultivar of the species, but we can all agree on the fact that native plant habitats are decreasing. So why should we care? Because native plants support beneficial insects and other wildlife.

So, you say, "Great, I hate insects!" "What good are they, anyway?" Would it surprise you to know that more than ninety percent of all insects are considered beneficial? In many cases, it's the beneficial insects that eat the pests and keep nature in balance.

Do you like songbirds? Did you know that the bulk of their diet is insects, and that, with a few exceptions, they feed their babies insects exclusively? If we had no insects, we would have no birds. Do you get excited when you see a beautiful butterfly in your yard? Remember, they ARE insects, and before that butterfly or moth looked like it does today, it was a caterpillar! Caterpillars are the primary food source for baby birds. People love to put out hummingbird feeders to attract the hummers. Did you know that they also feed nothing but insects to their young?

These are just a couple examples. There are millions of insects out there doing important jobs of which the average gardener is never aware. Of course, we all know about bees. Many people are afraid of bees. Did you know that only the females can sting? Bees are our most important pollinators, but most insects are pollinators, and that brings us back to the plants.

Bees and other insects go to plants in search of nectar and pollen. Both are an important food source for them. When they are nectaring, they are sipping the sweet sugar liquid of the plant, but they are also brushing against the pollen of the plant and moving it from the male to the female parts. This is pollination. It is the sexual side of plant life. Most plants have male and female parts on the same plant, often on the same flower. The male parts produce the pollen which must get to the undeveloped seeds in the ovary (the female part of the plant). If those seeds are never pollinated (fertilized), a mature seed will never develop, and the plant will not make fruit, or reproduce. In other words, without pollinators, we would lose a huge percentage of our plant life, which translates into a huge percentage of our food supply!

Are you beginning to see the importance of insects? Another important point to understand is that pollinators can nectar on any plant, but they need native plants as their host plants if they are to raise young. Every insect has specific plants that its babies can eat after they hatch out. That is the plant where the female lays her eggs. Some insects, such as the familiar monarch butterfly has only one acceptable host plant, but other insects may have several, usually within the same plant family. Whatever the host, it is always a native plant for a native insect. Conversely, there are some plants that can only be pollinated by a certain insect. If the plant or insect is extinguished, the other goes with it.

All native plants are host to somebody. The oak is credited with supporting the most species of wildlife. Native plants produce fruits, seeds, berries and nuts that all wildlife depend on for life. Imported plants may look beautiful in our landscapes, but, generally, do nothing to support any wildlife. Our native wildlife and plants have evolved together over thousands of years. An imported plant, although it may look the same to us, is not usually recognized as food by the local wildlife.

When William Penn came to view his chartered land in 1682, he found beautiful woodland and wildflower meadows along with clean, sparkling streams and rivers. He found wildlife in abundance. Today huge cities cover many acres of what was once wildlife habitat. Malls, big box stores with their massive parking lots, multi-lane highways and housing developments replace more habitat. Native plants are destroyed and replaced by imported ornamentals, or lawn grass. Worse, many imported plants, lacking natural controls, have escaped cultivation and invaded our few remaining natural areas crowding out the native plants that remain.

A personal choice

It has really come to the point where what we grow and how we manage our backyard landscape is very important to more than just ourselves. If you are interested in introducing some native plants to your property, remember that you need to site them correctly. Consider whether your planting area is wet, dry, sunny, shady, acidic, or neutral soil. Then do some research. To find lists of Pennsylvania native plants, go to the PA DCNR Native Plant website for an interactive plant search, or google Penn State Extension/ Native Plants.

Read other articles on ecological gardening & native plants

Read other articles by Barbara Mrgich