Jennifer Schultz Nelson
Extension Educator, Horticulture
Purple Fountain Grass
Many of us forget that foliage can be as interesting as flowers if chosen wisely. There are surprisingly diverse plant colors available, one of the most dramatic being purple. With the increasing popularity of using ornamental grasses in gardens, most of us have seen purple fountain grass (Pennisetum setaceum 'Rubrum'), even if we didn't know its name.
This plant has become a very popular choice in gardening with ornamental grasses for several very good reasons. One characteristic that makes it especially suited for central Illinois (although not as important this year!) is its drought tolerance. The deep purple foliage is topped by feathery flower spikes resembling bottle brushes from summer through the fall. The flowers make a unique addition to dried flower arrangements. Purple fountain grass is considered to be a moderately sized ornamental grass, with clumps growing to about four feet tall and two to three feet wide. This resilient grass requires little more than full sun and occasional watering after it is established. It is also a very versatile player in the garden. It can make a dramatic statement on its own, or when paired with other plants. Plants with yellow foliage or flowers look particularly striking when paired with purple fountain grass.
Unfortunately, purple fountain grass cannot survive Illinois winters, and it is grown as an annual here. Only those living in Zone 9 or above, the most southern parts of the U.S., can grow this species as a perennial. The rest of us are forced to buy new plants each year, as the variety 'Rubrum' is sterile and does not set viable seed. Depending on your needs, this may be a good thing. You won't be stuck battling seedlings that desperately want to take over your garden each year!