The oxeye sunflower has big beautiful blossoms beloved by bees and butterflies.
Oxeye sunflower is a large coarse perennial growing up to 5 ft (1.5 m) tall from a heavy fibrous rootstock. The thin 3-6 in (7.6-15.2 cm) dark green ovate leaves have sandpapery surfaces (both above and below) and toothed margins. They grow on short petioles, usually in opposite pairs, but sometimes arranged in whorls of three. From midsummer into fall, the plants bear 2 in (5.1 cm) flowers scattered singly atop loosely branched tall bare stems. The ragged daisylike blossoms are composed of 10-16 pointed yellow ray flowers and numerous orange disc flowers which mature into smooth 4-angled seeds. The most widely available cultivar is 'Sommersonne' or 'Summer Sun', a form of Heliopsis helianthoides var. scabra. It bears dark green foliage and profuse quantities of golden yellow flowers on plants only 30 in (76 cm) tall. 'Goldgreenheart' is a 3 1/2 ft (1 m) plant with double flowers that are lemon yellow tinged with green in the center. 'Ballerina' is a compact dark green plant with semi-double flowers. 'Gigantea' grows to 4-5 ft (1.2-1.5 m) and has semi-double flowers. 'Golden Plume' bears double yellow flowers. 'Karat' produces large rich yellow flowers on 3-4 ft (0.9-1.2 m) plants. 'Incomparabilis' has zinnialike orange-yellow flowers on 3 ft (0.9 m) plants. 'Ballet Dancer' bears large daisylike flowers with toothed rich yellow petals surrounding dark orange discs.
Oxeye sunflower in native to North America, from New Mexico east into South Carolina and north into southern Canada. Oxeye sunflower was originally a species of tallgrass prairies and savannas. It is now most commonly encountered in prairie remnants, woodland edges, open or rocky woods, and along old roads and railroads. It may grow at elevations up to 7,000 ft (2134 m).
Oxeye sunflower will grow in most any moderately fertile soil, including moist sands. New shoots may be slow to emerge in the spring, so you need to mark their locations and not be too quick to give up and plant something else on top of them. This is an erect growing, sturdy stemmed plant that can get by without staking a lot better than most of its back-of-the-border brethren. Lifting and dividing the plants occasionally will help keep them vigorous. This species is presumably adapted to near-annual prairie fires and should do well in meadows maintained by prescribed burning. Light: Oxeye sunflower prefers full sun, but will tolerate partial shade. Moisture: Oxeye sunflower likes good drainage and will tolerate dry conditions, but it performs best where the soil stays moist all summer.
Hardiness: USDA Zones 2 - 9. This species tolerates both severe winters and hot summers well.
Propagation:Heliopsis is easy to grow from seed. Sow the seeds outdoors about two weeks before the last frost. To produce transplants, start them in a greenhouse six to eight weeks before last frost. At 68-70ºF (20-21 ºC), the seeds will germinate in 1-2 weeks. Be sure to keep the young plants evenly moist. To propagate oxeye sunflowers vegetatively, take cuttings from non-flowering shoots in the summer or divide the clumps while they are dormant. New plants can be potted up in the fall and set out in the spring.
These oxeye sunflowers anchor a native plant demonstration garden at the Big Bone Lick State Park, Kentucky (heh, heh - I know I'm immature enough to think that's funny name...-Jack).
Oxeye sunflowers are usually grown in prairie restorations, wildflower meadows, casual borders, cottage gardens, rock gardens, and similar informal situations. In their book The Perennial Garden, Jeff and Marilyn Cox show photos of different Heliopsis helianthoides varieties in appropriate landscape settings. The leaves of this species have been employed in folk remedies, such as honey sweetened teas for loosening lung congestion or reducing fever. The stems have been used to treat malaria.
This is a great plant for the busy home gardener who expects his plants to give him more than he deserves. It will produce arm loads of flowers all summer long and never once ask for decent soil or proper care. It will even thrive on heavy clay where other flowers refuse to grow. And bees, wasps, flies, and butterflies will feed on the nectar and enjoy it while the "gardener" is away doing real work.
Left to its own devices, oxeye sunflower reseeds abundantly and tends to become a weed. It can easily be kept under control by autumn deadheading since it does not spread from rhizomes.