Downy sunflowers are known for their characteristic bluish-gray hairs that cover their leaves and stems, making them look a little as if they have been covered in ashes. These beautiful midsummer to early fall perennials have large, showy, yellow flowers that do not emit a strong fragrance. Downy sunflowers are wonderful additions to bird, pollinator, wild, cottage, and native gardens in dry soils with a lot of sun exposure. This species is native to the Chicago region according to Swink and Wilhelm’s Plants of the Chicago Region and current research.
Size and method of spreading:
At maturity, downy sunflowers are approximately 2 to 4 feet tall and spread 1 to 3 feet wide. Downy sunflowers self-seed and spread by rhizomes. The roots of this plant will also send out chemicals (allelopathic) that suppress the growth of other nearby plants. This allows them to rapidly form dense colonies.
Native geographic location and habitat: (include C-value if appropriate)
Downy sunflowers are native to the Eastern and Central United States. C-value: 9.
Attracts birds or pollinators:
Bees, butterflies, moths, caterpillars, and flies are visitors of this species. Birds like to eat the seeds of downy sunflowers.
Leaf description:
The leaves of the downy sunflower occur in approximately eight to 17 opposite pairs along the length of the stem, with each pair at a right angle to the pairs above and below (decussate). The individual leaves (simple) attach directly to the stem (sessile) or slightly surround it (clasping). The upper and lower surfaces of the leaves are covered in short, bluish-gray hairs, for which this species is named. The edges of the leaves are smooth (entire margins) or can have some slight serration. The bases of the leaves may be slightly heart shaped (cordate) or just wider at the base (elliptic), and taper to a pointed tip.
Flower description:
Similar to daisy flowers, the downy sunflowers are composites of petallike ray flowers surrounding a group of tubular disk flowers. There are typically between 15 and 30 ray flowers that are bright yellow in color. The numerous disk flowers in the center are a slightly darker yellow than the ray flowers. There are also green, leaflike bracts that sit below (subtend) the base of the inflorescence in multiple layers (involucre). As the sunflower name suggests, these flowers will orient themselves to face the sun throughout the day.
Fruit description:
Like other sunflowers, downy sunflower fruits are small, dry, wedge-shaped, and slightly flattened (achenes).
Plant care:
Downy sunflowers are low maintenance if planted in the proper conditions. High winds can be an issue for downy sunflower’s shallow roots, and staking may be necessary. Avoid overwatering to limit fungal growth. Division may be necessary.
List of pests, diseases, and tolerances:
Downy sunflower plants are not susceptible to major disease. Minor fungal issues such as powdery mildew, rust, or fungal leaf spot can be an issue in poorly drained soils. The sunflower head-clipping weevil (Haplorhynchites aeneus) is fond of downy sunflowers, and may clip the heads, causing them to droop or fall off.
