Geum is a genus of flowering herbaceous plants in the family Rosaceae. They are small perennial plants native to many continents. More commonly known as avens, these types of plants require well-drained soil. They also tend to perish if grown over the winter in wet soil. Many hybrids have been created and are frequently grown in flower borders or rock gardens.
The avens species and hybrids that are cultivated are typically 8 to 30 inches (20-76 cm) tall. The plants produce flowers on a single stem. Being members of the rose family, these blooms resemble those of small roses. The colors of the hybrid flowers are yellow, orange, or red.
The Geum plants grow in mounds. The moisture regime in which they are found in their natural habitat depends on the type of landscape. In arid areas, they tend to be found in areas that are more moist. In areas that are prone to more moisture, they grow in drier spots. Plants in this genus have a tendency to succumb to downy mildew and powdery mildew, diseases that strike when there is too much moisture.
Avens are ideal plants for parts of the garden that only receive minimal care. The hybrids grow best in a soil of sandy loam that has good drainage. They should be divided every few years in the fall or early spring, with division being the best method of propagation. Plants can also be raised from seeds.
One species of Geum that is commonly grown is Geum triflorum. This type of avens is commonly known as old-man’s whiskers or prairie smoke. It is known as prairie smoke, because, when seen from a distance, large numbers of the plants give the appearance of a prairie being on fire. The term old-man’s whiskers comes from the clusters of hair, up to 3 inches (8 cm) long, on the seed pods of the plants.
Prairie smoke is drought resistant and easily grown. It grows best in full sun, but is also tolerant of some shade. The plant grows to be 6 to 12 inches (15 to 30 cm) in height. The furry leaves are often green all year round, and the pinkish-tan, nodding flowers are borne in the spring and summer, and average three at a time on a single stem. The plant often forms mounds 8 to 16 inches (20 to 40 cm) wide. Prairie smoke should be planted at 12 inch (30 cm) intervals and spreads quickly.
In its native habitat, prairie smoke is often found colonizing disturbed sites. One type of disturbed soil that the plant grows well on is gopher mounds. The plant is found across the continental United States, in fields and prairies at a wide range of elevations.