Native to the prairies of North America, wood grass (Sorghastrum nutans) is a tall, bunching, warm-season grass that is also used as feed for livestock.
A popular ornamental grass, it works well as an upright backdrop in garden borders, or as a main mass feature when creating a natural meadow or wildlife garden. The fast-growing grass grows to be up to 6-feet tall when in bloom, and the seed-heads add a splash of yellow-to-orange color from late summer to early fall.
Because the short rhizomes are able to remain standing in winter while dormant, it can continue to add interest to your garden throughout the year. The grass blades add hues of green, grey, and even blue to the landscape. Plant wood grass from late May to early June.
As a result of its hardiness, clumping formation, strong rooting system, and ability to grow in infertile soils, wood grass can work well on slopes to prevent erosion.
Wood grass is highly flammable, and if you live in an area with a high risk for fire, it's recommended that you do not plant this grass within the defensible space of your home.
|Botanical Name||Sorghastrum nutans|
|Common Name||Wood grass|
|Mature Size||Up to 6 ft. tall|
|Soil Type||Adapts to a variety of soil types|
|Soil pH||Acidic, neutral, alkaline|
|Bloom Time||Late summer to early fall|
|Flower Color||Yellow to orange|
|Hardiness Zones||4–9 (USDA)|
|Native Area||North America|
|Toxicity||Nontoxic to humans and animals|
Wood Grass Care
Providing wood grass gets plenty of full sun, this could be an easy to grow, relatively low-maintenance addition to your garden. It adapts well to a variety of soils, and it can cope with dry conditions and even occasional flooding.
This plant reseeds easily and needs minimal attention once established.
The one thing that wood grass really does need to thrive is a sunny position. Without full sun for much of the day, it won't perform to its best potential. Ideally, the grass should be exposed to around six hours of direct sun every day.
This ornamental grass isn't particular about the type of soil it's planted in. Heavy clay and dry, infertile soils all still usually result in a good performance if the plant has access to the sun.
Its only preference is not to be consistently overly moist, so make sure the soil is well-drained. If this grass gets too much moisture, it can start to flop.
Don't be tempted to water your wood grass too frequently. This can result in sprawling stems that aren't as strong. Once established, this plant is fairly drought tolerant and copes well in dry to medium conditions.
Temperature and Humidity
Warm-season grasses prefer a drier environment and mild temperatures. Optimum temperatures are around 85 to 95 F, but anything over 60 F usually produces decent results.
Wood grass doesn't need fertilizer to thrive. In fact, it's best avoided as it can result in the roots becoming weak and overly long. The only time you might want to consider light fertilization is when you're trying to get very young grass established.
Cutting back wood grass to the ground in late winter to early spring can encourage more impressive growth the next year. If you want to appreciate the grass in winter or allow the remaining seed-heads to act as feed for birds and other wildlife, wait until early spring before you do this. Just make sure you've done it before any new growth begins; You shouldn't cut the grass back in its first year of growth. If your garden is small, you may want to deadhead during the fall to prevent excess self-seeding.
Propagating Wood Grass
Wood grass does well being grown from seeds. Division is possible, but it isn't recommended. The root system is sprawling, thick, and complicated, so it can be tricky to separate successfully.
How to Grow Wood Grass From Seed
This grass germinates easily from seeds. You can either sow them in the fall, or you can stratify them before sowing them in the spring. These seeds need soil temperatures above 50 degrees Fahrenheit for germination to be successful, and the soil should be kept moist while establishing. Wood grass is a rapid grower and reaches maturity by its second year.
Wood grass can fall prey to aphids, spider mites, and spittlebugs. All can be remedied with insecticidal soap or neem oil.
Leaf spot diseases also like wood grass; they are group fungal diseases that can be cured by both making sure the plant is neither overcrowded nor overwatered, and applying a fungicide to diseased areas.