In Praise of Native Plants

Ordinarily, February is not my favorite month. Patience isn't my virtue. I become out of sorts when not engaged in productive work, physically. I keep thinking about all the things that need to be done while realizing there's nothing much I can do about them until, well, spring arrives. This Chantilly greenhouse cured me that February blue this year.

We completed sowing: 104 species, 724 trays of pots, and more than 16,000 small pots of native plants from the seeds we collected last year. We could have easily doubled these numbers if we have the space!

More than third of these pots are devoted to grass and sedge species. Altogether, we've sown 33 species of native grasses and sedges, without counting the ones already available at our nursery in Springfield. There's a good reason for it.

When you visit wild areas —whether it be open dry meadow, moist open areas near streams, woodland openings, shaded hillside, or marsh— what you will see first is grass or grass-like species on the ground. Grasses make up of large percentage of our native vegetation in any type of wild areas. Grasses are baseline plants whose presence help make the ground more hospitable to other plants and insects.

Let's suppose that you have an abandoned field and want to return it to a lush meadow with some shrubs on the side. My advice is to start with grass species, especially if you are dealing with the bare ground.

The bare ground can be surprisingly harsh for small plants to survive. The bare ground responds quickly to the sun's radiation. During the day, it heats up quickly and during the night, it cools off as quickly. The surface temperature fluctuates dramatically. When the ground is bare, it is also hard to control the moisture level in soil. It has no mechanism to retain, regulate or budget the water. In winter, it's hard to retain snow cover on the bare grounds. When not protected by snow cover, the ground goes through a freeze-and-thaw condition repeatedly, thereby damaging the roots of small plants. The frost would lift the roots of small plants right out of the ground. In summer, the temperature at the surface level on the bare ground can be surprisingly high. Such is the microclimate at the ground level.

Our native grasses could change this microclimate condition in many good ways. Their robust root systems make the ground more porous, absorbing water easily and retain water longer. Their shade would lower surface temperature and would retain soil moisture better. They would also help cut down surface winds. In the wild, grass almost always takes hold of the ground before other flowering plants are arriving. It therefore creates a more hospitable condition for other small plants with more equitable temperature, higher humidity, and more porous soil. The ground, with small plants of just two to three inches of height, is now becoming an inviting habitat for many small insects and other invertebrates.

This doesn't mean that you have to grow grasses exclusively in the first year. It rather means that you should use grasses as baseline plants to support other and more delicate flowering plants and young woody seedlings. It's like background coloring in painting.

When you are planting young woody seedlings in the bare ground under the full sun, you should cover the ground with warm-weather bunch grasses like Little Bluestem and Broomsedge to give the needed protection for woody seedlings.The grasses would create more hospitable microclimate for them. In the natural setting, the young woody seedlings receive lots of protection from older trees above (shade) and the organic debris in the ground (nutrients and moisture).

Our native grasses and sedges also function as an excellent barrier to unnecessary erosion. Often their root systems behave like a huge, continuous mat underground. In floodplain, small sedges colonize the sandy ground, thus making the whole area more stable and able to sustain from repeated flooding. It works much the same way on the drier hillside. The sedges and grasses are the working soldiers to hold the soil intact on the slope.

We are able to grow fewer than 40 different species of grass at the moment. That's a fraction of grass species that are growing naturally in our region. Their preference for a type of soil and for other conditions are quite varied. Some species prefer dry and sunny meadows while others favor shaded woodlands. Some need to stand in wet, while others insist on a narrow strip of in-between places. Their preferences are as varied as there are many different types of soil make-ups in our region.

I always think of flowering plants as inserting plants in between grasses. If the bare ground is a canvas, I would first give a broad brush work over the canvas to create a background depth. Our native grasses work much the same way.