How to Plant and Grow Bachelor's Button

Bachelor's button, also known as cornflower because of its prevalence in cornfields in its native Europe, is a cutting garden and cottage garden favorite. Grown for its bright blue, fringed flowers, the stems last for days in a cut flower arrangement. As a rugged reseeding annual that's hardy in Zones 2-11, bachelor's button will pop up year after year without needing much help from you.

In addition to cornflower blue, bachelor's buttons flowers come in many shades of pink, purple, white, and almost black. Along with showy blooms, bachelor's button leaves are an appealing silvery-green that mixes well with other plants, including grasses and wildflowers.

Where to Plant Bachelor's Button

For the best growing conditions, choose an area in full sun. Bachelor's button will grow in nearly any Zone, so you can plant it in your garden and be confident it will grow.

Once established, expect bachelor's buttons to sprout in the same spot year after year. In addition, bachelor's buttons produce copious seeds, attracting small birds such as finches.

How and When to Plant Bachelor's Button

For the best display, plant closely together to keep plants upright and rigid and to prevent them from becoming too leggy. Bachelor's buttons are one of the easiest plants to grow from seed. Plant the seeds in the fall for spring bloom. Alternatively, you can plant seeds in early spring, two to three weeks before the last frost.

Growing bachelor's buttons can be as simple as throwing a handful of seeds onto some freshly turned soil. Given their almost weedy nature, it's easy to see how these plants grow in many gardens.

Bachelor's Button Care Tips

Light

Grow bachelor's buttons in full sun, but a bit of shade is fine in the afternoon, especially when it gets very hot in summer. They'll be leggy and won't stand up straight when planted in mostly shady spots.

Soil and Water

While their ideal soil conditions are sandy loam, these plants tolerate poor soil conditions. Well-drained soil will keep bachelor's buttons flowers thriving. Avoid wet soil; bachelor's buttons are prone to rot if the roots get too wet. Water when the top 1 inch is dry to the touch, and when temperatures are higher than usual, give them more water.

Temperature and Humidity

Bachelor's button will grow best in 60ºF to 80ºF but will flower more profusely when temperatures go up to 85ºF to 95ºF. They like 30 to 50 percent humidity but need to be watched when it's especially humid because they can contract fungal diseases when there's a lot of moisture in the air.

Fertilizer

These plants will do fine in most types of soil, but if you want to give them a boost, add compost or a balanced, slow-release fertilizer before you plant the seeds. If you want to add fertilizer once planted, wait until they're about 6 inches high and use a natural liquid manure product. For the amount to use, follow product label instructions.

Pruning

Pruning isn't necessary for bachelor's buttons, but if you prune them, they'll flower for a longer time. Cut back the growth by about a third in midsummer or when the plants start to look scraggly or faded.

Potting and Repotting Bachelor's Button

Bachelor's buttons won't last long in pots, but you can still enjoy them in containers. Plant bachelor's buttons in clay or terracotta pots with ample drainage holes for optimal water draining. Use quality soil with perlite or a soilless medium such as cactus potting mix. Deadhead as often as needed to keep your pot looking pretty.

Pests and Problems

Because of it's brief growing season, bachelor's buttons rarely have any problems with pests. If you see aphids or mealybugs on your plants, spray them with water to remove them. Fungus like powdery mildew may develop, but it's better to remove the plants and let new ones grow instead, since the growing season is brief.

How to Propagate Bachelor's Button

Bachelor's buttons flowers bloom from early summer to just before frost. Remember that these are true annual plants; if you remove all the spent blooms, you'll also remove all future generations of flowers. Save some seeds for future use. However, remember, they're open-pollinated seeds: If you had a pure pink variety, the next round of blossoms might have some purple and blue in the mix.

Types of Bachelor's Button

'Black Ball' Bachelor's Button

Centaurea cyanus 'Black Ball' has purple-black flowers and grows 3 feet tall.

Bachelor's Button Companion Plants

Globe Amaranth

Globe amaranth thrives in hot conditions, blooms nearly nonstop, and its interesting pom-pom flowers are great for cutting and drying. It also attracts butterflies. Globe amaranth will thrive and bloom until frost. It's excellent in beds, borders, and containers. Plant established seedlings outdoors in spring after all danger of frost has passed. It tolerates a variety of soils and moisture levels. Be careful not to over-fertilize.

Salvia

Whether you have sun or shade, a dry garden, or lots of rainfall, there's an annual salvia that you'll find indispensable. All attract hummingbirds, especially the red ones, and are great picks for hot, dry sites where you want tons of color all season. Most salvias don't like cool weather, so plant them outdoors after all danger of frost has passed.

Snapdragon

Snapdragon comes in gorgeous colors, including some with color variations on each flower. They're a cool-season annual, coming into their own in early spring. They're also great for fall color. Plant snapdragon in early spring, a few weeks before your region's last frost date. Deadhead regularly for best bloom and fertilize regularly. Snapdragons often self-seed in the landscape if not deadheaded, so they come back year after year, though the colors from hybrid plants often will be muddy looking. In mild regions, the entire plant may overwinter if covered with mulch.