Frost Damage on a Black-Eyed Susan

Annual Varieties

• Annual black-eyed Susans vary in their tolerance for frost. Because some tender annuals suffer severe damage from frost, protecting your black-eyed Susan variety from frost is wise unless you are familiar with its frost tolerance. Black-eyed Susans grown in pots or other containers can be moved to a sheltered location when frost threatens while those in a garden bed can be covered with sheets or other fabric to keep frost at bay. Because two to three weeks of good weather usually occur after the first fall frost, moving or covering the plants to protect them from frost damage then removing or uncovering them allows you to enjoy their appearance until well into fall, when consistent cold weather arrives. Annuals complete their life cycle in one year and do not return the following year. So annual black-eyed Susans should be discarded or added to a compost bin.

Biennial Varieties

• Biennial black-eyed Susans produce a rosette of leaves their first year and bloom their second year. When grown in a garden bed, they typically act like perennials because first- and second-year plants coexist in the bed. Although the plants will not appear in the same location from year to year, growing them in a perennial garden bed generally provides an abundance of blooms from them each year. Biennial black-eyed Susans tolerate a light frost with minimal damage to their foliage and continue to bloom until a hard frost strikes. A hard frost kills the foliage, but the roots of the first-year plants survive and produce large, showy plants the following year. The roots of the second-year plants do not survive.

Perennial Varieties

• The perennial black-eyed Susans live for many years. These flowering plants remain in the same location in a garden bed, allowing you to maintain the same garden design from year to year. The perennial varieties tolerate light frost, but heavy frost kills their foliage. Their roots, however, survive winter and send up new shoots in spring.

Wild Varieties

• Wild black-eyed Susans line roadsides and grow in meadows, setting the land aglow with their yellow-orange blooms from early summer into fall. Because those plants may be annuals, biennials or perennials, they create an ever-changing tapestry of color from year to year. Like other black-eyed Susans, most wild varieties survive light frosts and are killed when a heavy frost arrives.