Scarlet Cinquefoil in the Landscape

Stephen Love, University of Idaho

Scientfic Name:  Potentilla thurberi
Common Name:  Scarlet cinquefoil, Thurber’s cinquefoil

Description:  Scarlet cinquefoil is a very unusual plant, as evidenced by the dark red flowers on plants from a family of yellow-flowered species. The combination of dark green leaves and bright scarlet flowers creates a startling visual combination. Potentilla thurberi is an herbaceous, very long-lived perennial. Plants produce numerous stiff, highly branched, upright to spreading stems as much as 18 inches tall. Dark red flowers decorate the tips of the branches for at least eight weeks in mid-summer. The foliage remains attractive throughout the summer. Scarlet cinquefoil will provide striking color in any mixed perennial bed or borders.

Native Habitat:  Native distribution of scarlet cinquefoil is limited to a geographical region on either side of the Arizona, New Mexico border. Its primary habitat includes coniferous forests, moist meadows, and riparian communities at high elevations, 5,500 to 9,000 feet.

Cultural Requirement

Soil:  Adapted to a wide range of soils, including those with high pH. Performs best in heavier soils with higher moisture-holding capacity and some organic matter.

Moisture Tolerance:  Considering its riparian origins, scarlet cinquefoil is remarkably drought tolerant. Prefers moderate summer-long moisture but can survive and bloom in moderately xeric conditions.

Sun/Shade/Preference:  Thrives in a range of light exposures from full sun to moderate shade. More sun equates to more flowers.

Transplanting:  Transplants easily, both from pot to pot and from pot to garden. Seedlings transplant successfully at the 3 to 4 true leaf stage Seedlings develop rapidly and maintain well in pots of any common size up to 1-gallon.

Propagation:  Best propagated from seed. Requires 6 to 8 weeks of cold stratification. Germination rates are usually very high. Seedlings exhibit few problems. Can be vegetatively propagated via crown division.

Maintenance (pruning, fertilization, deadheading, division, irrigation, etc):  Remove dead foliage in the spring. Trim the flower stalks back to the basal leaf mound as bloom wanes. Under conditions of adequate moisture, plants will rebloom if deadheaded. For best bloom, provide consistent supplemental irrigation (every 10 to 15 days during the hottest part of the summer). Occasional fertilization may be required to invigorate older plants.

Insect, disease, or other problems:  Scarlet cinquefoil has no serious pests or diseases.

Landscape Value

Use in the Landscape:  Scarlet cinquefoil can be employed to provide color to any mixed perennial bed. It is best placed with other plants that require some supplemental irrigation during summer months. Moderate shade tolerance allows this plant to be used to fill in around trees and shrubs.

Foliage:  The large, five-fingered leaves form a loose mound. The color of the foliage is deep green, a marked contrast to the dark red flowers. The foliage is vibrant and healthy from early spring until very late fall.

Flower:  Flowers develop on the ends of spare, highly branched stems. The 5-petaled flowers are about ¾ inch in diameter and dark, velvety red.

Timing:  June-August.

Fruit:  The fruits are composite like the related strawberry, but are dry rather than fleshy. Individual seeds, tan, oval and small, comprise the actual fruits.

Form:  Mounded in the foliar phase, sparse and openly spreading in bloom.

Texture:  Moderately coarse.

Ultimate Size:  Prebloom: 6 to 10 inches tall; in-bloom: 15 to 20 inches tall with slightly greater spread.

Rate of Growth:  Seedlings develop at a moderately rapid pace. Foliage is usually well-developed and attractive by the end of the first season. The plants never bloom the first season and seem to need winter cold to trigger bloom the second year

Suggested Plant Partners:  One consideration with scarlet cinquefoil is complementation of the dark red flower color. Plants that bloom white or blue make excellent companions. Many blue-flowered penstemon species add complementary color, including Penstemon venustus, Penstemon humilis, Penstemon hallii, Penstemon subglaber, and Penstemon mensarum. Other good companion plants are Delphinium occidentalis, Erigeron glaucus, Erigeron speciosus, and Anaphalis margaritacea. This species can also be effective when placed around the base of native trees and shrubs, such as Acer glabrum, Amelanchier alnifolia, and Sambucus caerulea.

Availability:  Available as potted plants from mail order native plant nurseries, primarily those located in the Southwest. Seed can sometimes be purchased from native plant seed suppliers.

Cultivars:  One cultivar, ‘Monarch’s Velvet’ is occasionally available in the nursery trade.

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