Grow and Care for Mexican Sunflower

Grow Mexican sunflower in full sun and poor-to-average soil that drains, and water it until the plant settles in. Mexican sunflower is Tithonia rotundifolia — a heat-loving annual from Mexico, not a garden sunflower.

Give it full sun, lean soil that drains, and water until it settles

Mexican sunflower is a fast annual that reaches about four to six feet in one summer, with coarse hairy leaves and brittle stems that hold 3-inch orange-red daisies. Sit it in full sun in soil that is only average, because rich ground and heavy fertilizer push foliage at the expense of flowers and leave stems that cannot hold themselves up. [1] It thrives in heat. Water a new planting until the roots take, then let dry spells pass; once it is settled it handles drought better than a weekly soak. [2] Deer usually skip the fuzzy leaves. Bees, butterflies, and hummingbirds work the heads from midsummer until frost.

Plant after frost, two to three feet apart, and stake the tall ones

Set nursery six-packs out after the last frost, when nights stay warm, in a bed you will not need to move later. Plant each one at the same depth it grew in the pot, then water it in the same day. Space plants about two to three feet apart so neighboring stems can lean on each other; if you stake each plant, you can give them a little more room. [3] The stems are brittle, so a fence, a wall, or a stake on the windward side keeps a storm from snapping the hollow flower stalks. To raise it from seed instead of a six-pack, see Growing Mexican Sunflower From Seed.

1. Wait until after the last frost, when nights stay warm.
2. Set each plant at the same depth it grew in the pot, in full sun and soil that drains.
3. Space plants about two to three feet apart, then water thoroughly the same day.
4. Stake tall plants, or site them where a fence breaks the wind, because the stems snap easily.

Pinch young plants, deadhead, or shear a third if they get lanky

Pinch the tips once while the plant is still young so it branches lower and stands better without a stake. If it races up lanky in early summer, cut it back by about a third; new side shoots fill in, and the plant stays shorter. Deadhead spent heads through the season if you want more flowers; leave some heads late if you want goldfinches on the seed, or if you plan to collect it.

• Pinch once on a young plant so it bushes out.
• Shear about a third in early summer if the stems are already too tall and thin.
• Deadhead for more bloom, or leave late heads for seed and birds.

Cut stems for a vase

The open daisies last in a vase. Cut a stem when the flower is open, and get it into water the same day so the hollow stalk does not wilt on the bench.

1. Cut the stem when the flower is open.
2. Stand it in a deep vase of warm water the same day.

Plant it with other hot-colored annuals that share full sun, such as How to Grow Zinnias, and keep rich feed and extra water off the bed.

Not a garden sunflower — and not tree marigold

The common name is the usual mix-up. A garden sunflower is Helianthus, often one large head on a tall stalk, grown for seed or a cutting series. Mexican sunflower is a different genus: many orange-red daisies on a branched annual, with hairy triangular leaves. [4] If you meant the big annual, read How to Grow Sunflowers instead. False sunflower is Heliopsis, a perennial border clump — see How to Grow False Sunflower if that is the shop tag.

Tree marigold is Tithonia diversifolia, a perennial shrub with pointed leaf lobes and larger yellow heads. It is not the orange annual in the packet, so do not treat a woody Mexican sunflower as this plant. Zinnia can look similar in a small photo; zinnia heads are usually fuller, and the plant is a different genus — see How to Grow Zinnias if the tag says zinnia.

If the stems flop by midsummer, the soil was probably too rich or the plant never got a stake. Next year sit it in leaner ground, pinch it once while it is young, and keep extra fertilizer off.