Fountain grass, belonging to the genus Pennisetum, is a popular ornamental plant known for its arching foliage and soft, bristly plumes that resemble a water fountain. Many gardeners wonder if this attractive grass will reappear after the winter dormancy period. Whether the grass returns each year depends entirely on the specific variety planted and the climate where it is grown. This is because different types of fountain grass are treated as either enduring perennials or short-lived annuals.
Understanding Hardy vs. Tender Varieties
Fountain grasses are categorized into two groups based on cold tolerance. Hardy varieties are true perennials, equipped to survive a typical winter freeze and return for multiple seasons. Common examples include Chinese fountain grass (Pennisetum alopecuroides) and its cultivars like ‘Hameln’ or ‘Redhead’. These varieties are generally cold-tolerant down to USDA Hardiness Zone 5, meaning they withstand average minimum temperatures well below freezing.
The second group is the tender varieties, which cannot survive sustained freezing temperatures, making them effectively annuals in most climates. The most widely planted example is Purple Fountain Grass (Pennisetum setaceum ‘Rubrum’). This striking plant is only a true perennial in the warmest regions, typically USDA Zones 9 through 11, where temperatures rarely dip below 20°F.
If planted in a colder region, tender varieties lack the genetic ability to survive winter outdoors. Gardeners often assume the plant is perennial due to its vigorous growth habit. Identifying the precise species and cultivar purchased is the only way to know the plant’s capacity to return.
Essential Winter Preparation for Survival
For hardy perennial fountain grass, preparing the plant for winter increases its chances of survival. The most important step is resisting the urge to cut back the foliage in the fall. This is a common mistake because the standing, dried leaves and stems act as a natural blanket, providing insulation to the crown, which is the plant’s growing point.
Ensure the plant’s crown remains protected from excessive moisture throughout the winter. Wet, cold soil often leads to rot and can be more damaging than freezing air temperature. Planting in a location with excellent drainage is the best preventative measure.
Applying a layer of dry, organic mulch is a helpful secondary form of protection against freeze-thaw cycles that can heave the crown out of the ground. Apply a two- to three-inch layer of light material, such as pine needles or shredded leaves, around the plant’s base after the ground has frozen solid. Keep this mulch slightly away from the center of the crown to prevent moisture from accumulating on the dormant plant tissue.
Assessing and Encouraging Spring Revival
Fountain grass is a warm-season ornamental grass, meaning it is one of the last plants in the garden to break dormancy. Do not be alarmed if you see no new growth when other plants are leafing out in April. The grass waits until soil temperatures have warmed considerably, often not showing signs of life until late May or early June.
The proper time to cut back the old, brown foliage is in late winter or early spring, just before new shoots emerge. Use sharp shears to cut the entire clump back to a height of four to six inches above the soil line. This clears the way for emerging green growth and improves air circulation.
To check for viability, look closely at the crown for small, bright green shoots emerging from the base. If no shoots are visible, lightly scratch the tissue near the crown. A firm, pale yellow or greenish color suggests the plant is still alive, while soft, brown, or mushy tissue indicates it likely perished. Once new growth is visible, a light application of compost or a low-nitrogen fertilizer can encourage vigor, though established fountain grass requires very little supplemental feeding.