The Unseen Benefit of Native Grass
By Linda Langelo, CSU Horticulture Program Associate
There is more to grass than just mowing, weed prevention, fertilizing and aerating. Grass, both hybridized and native grass, plays a very important role in the world not frequently on the minds of grass lovers. Panicum virgatum, Switchgrass with a deep root system traps coarse sediment and plant nutrients from farm fields. Yes, that's right, root systems do this. The unseen part of the grass not only supports the grass's health, but also helps our landscapes filter water. The larger the area of grass in the landscape, the more opportunity to better filter the water over time especially with types of grasses with deep root systems. These would be primarily native grasses.
According to Ronald R. Schnabel in his article, Improving Water Quality Using Native Grasses, "Native grasses improve water quality, both in limiting the source of pollutants and intercepting pollutants before they enter a water body." Native grasses are more than just about conserving water usage, reducing herbicides and fertilizers.
In fact, native grasses and plants have deeper root systems that can go several feet into the ground. A grass's genetic make-up and environment factors play a role in root depth. In general, the grass with more top growth also produces a significant amount of root growth to support the top growth. Big Bluestem, Andropogon gerardi, grows a root system spreading nine feet in the ground. With roots to this type of depth, we do not usually think about cleaning the water, but rather soil stabilization and a decrease in floodwater.
Buffalo grass used more frequently in home landscapes has a root system that reaches to a depth of eight feet. The deeper the root system, especially in clay soils, the more water is absorbed and retained in the soil. With the more popular turf grass, Kentucky Blue, the roots reach six to eight inches in depth.
Here is a short list of other native grasses that help with improving water quality and can be added to enhance the natural beauty of the landscape:
Andropogon scoparium - Little Bluestem
Bouteloua curtipendula - Side Oats Gramma
Sorghastrum nutans - Indiangrass
Sporobolus heterolepsis - Prairie Dropseed
Panicum virgatum - Switchgrass
Some of these native grasses are very attractive. Most cultivated varieties appear in cultivation. Some have cultivated varieties have been crossed within the same Genus and now in a hybridized form bears a particular attractive feature that breeders produce. Some are found naturally in the wild and just brought into cultivation. Some are found in seed batches of other cultivated varieties and are called genetic mutations that change the appearance of the plant in some way. According to Moon Nursery, Dr. Hans Simon spotted Panicum virgatum 'Shenandoah' in a batch of seedlings of Panicum virgatum 'Hanse Hermes'. This seed was an attractive mutation. It was chosen for its short compact habit and improved red color. Simon named the plant for Virginia’s Shenandoah Valley as a tribute to the species’ country of origin. Here are some other cultivated varieties you may be familiar with of Panicum virgatum listed below. Many of these cultivated varieties of Switchgrass have been in the trade for over 15 to 20 years.
1) Cloud Nine - 5 to 6 feet
2) North Wind - 5 to 6 feet
3) Dallas Blues -6 to 8 feet
4) Heavy Metal -2 to 3 feet
5) Shenandoah -2 to 3 feet
Take a look below at pictures of the native grasses listed above and judge for yourself the merit they might have for a place in your landscape.
Photo credit: www.omcseeds.com Sporobolus heterolepsis
Photo credit: L&H Seeds, Indian Rice Grass
Photo credit: Tri Valley, Side Oats Gamma
Photo credit: North Creek Nurseries, Little Bluestem
Photo credit: North Creek Nurseries, Switchgrass
So I hope you look at native grasses differently. I also must add that grass also produces oxygen. That goes for all grasses. There are plenty of native plants that can enhance your native grasses creating beautifully landscaped properties that are sustainable environments.
This is an early plug for a 2018 conference - Landscaping with Colorado Native Plants, February 10, 2018 at the Denver Botanic Gardens. Click on the following link for more information: https://landscapingwithcoloradonativeplants.wordpress.com/ .
Native plants in general have some wonderful qualities. Please keep this workshop in mind.