Mexican sunflower
* Common name: Mexican sunflower
* Botanical name: Tithonia rotundifolia or speciosa
* What it is: Mexican sunflower is a tall, daisy-family, annual flower with large, three- to five-inch-wide yellow, orange, or red-orange blooms. It’s native to Mexico and central America and is attractive to a variety of pollinators and beneficial insects, including bees, monarch and tiger swallowtail butterflies, and syrphid flies.
Mexican sunflowers are easy to start from seed planted directly in the ground in mid-May, although blooms won’t start until July. Then plants will flower continuously, though, until frost. Young transplants also are sometimes available at garden centers.
Deer hardly ever bother Mexican sunflowers.
* Size: The straight species blooms orange and grows tall and bushy to four to six feet tall. Yellow Torch is a yellow-blooming variety that grows about that big as well. Torch is a red-orange bloomer that grows to a more compact four feet tall, while Fiesta del Sol is a 2000 All-America Selections award-winner that blooms orange and early and tops out at three feet tall.
* Where to use: Mexican sunflowers do best in full sun and are very heat- and drought-tough. Because of their height, they’re best used as a back-of-the-border annual in a sunny flower garden or mixed in a sunny pollinator garden or meadow garden.
Mexican sunflowers also make good cut flowers.
* Care: Plant seeds or transplants after danger of frost passes in spring (mid-May or after). Keep soil damp the first few weeks to aid rooting, then water is needed only in extended dry spells.
Work compost and timed-release flower fertilizer into soil at planting. If you do that, supplemental fertilizer usually isn’t needed. Otherwise, a scattering of granular, balanced flower fertilizer two or three times during summer may boost flowering, especially if your soil is lean in nutrients.
Stems and stalks are sturdy enough to prevent flopping most of the time, especially when Mexican sunflowers are interplanted and have neighbors to lean on. Otherwise, staking will help keep them upright. The compact Fiesta del Sol is stocky enough to avoid flopping.
Deadheading of the flowers isn’t needed. Yank and compost plants after frost kills them in fall.
* Great partner: Zinnias, coreopsis, gaillardia, black-eyed susans, hardy hibiscus, and true sunflowers (Helianthus) are other brightly colored, sun-loving flowers that pair well with Mexican sunflowers. Dark-leafed ninebark is an excellent shrub partner.