How to Grow and Care for Cornflower (Bachelor’s Button)

Cornflower Care

Here are the main care requirements for growing a cornflower:

• Plant in full sun with some afternoon shade.
• Stake the plant to avoid flopping.
• Use rich, well-draining soil.
• Water 1 inch per week.

Light

Cornflower prefers full sun but it will tolerate a bit of shade in the afternoon, especially during the dog days of summer. Shady conditions all day cause the plant to grow leggy and prone to flopping.

Soil

Cornflower grows best in rich, well-drained garden soil, on the alkaline side, with a pH of 7.2 to 7.8. If your soil tends toward acidic, add crushed limestone to your garden beds

Water

Cornflower needs the equivalent of 1 inch of water per week, especially during the hottest months of July and August. Allow the soil to dry slightly in between waterings, but don’t let it dry completely or the plant will flop. If this happens, a good, thorough drink will usually perk it up.

Temperature and Humidity

When it comes to temperature, cornflower tolerates both a light freeze as well as a hot summer day. This plant thrives in 60 to 80 degrees F. temperatures but may need 85 to 95 degrees F. to reach flowering maturity. Cornflower grows best with an average humidity range of 30 to 50 percent. Keep a close eye on your garden during humid spells, though, as this plant is susceptible to fungal disease under these conditions.

Fertilizer

If your soil is poor, fertilize your cornflower monthly with diluted liquid manure or compost tea. Start fertilizing in the early spring when the baby plants are 6 inches tall, and continue throughout the summer. If you have rich soil, you don’t need to feed your flowers at all. Often mixing a bag or two of compost into the soil before sowing is enough for the entire season.

Types of Cornflower

Most people are drawn to traditional vibrant blue cornflowers. You’ll often see this variety cropping up along roadsides or in the pastures of rural areas. However, other cultivars lend an equally attractive appeal, blooming in colors of white, pink, or red.

Below are a few of the favorites:

• An heirloom variety, ‘Blue Boy’ boasts thistle-shaped flowers of periwinkle blue. Plant this variety early in the spring for a show-stopping landscape display.
• The ‘Tall Double Mixed’ series provides a great option for a cutting garden, as the blooms of white, pink, and blue make attractive dried arrangements.
• The striking ‘Blackball’ variety provides a nontraditional option, complete with crimson poms that hold nectar coveted by birds.
• ‘Dwarf Blue Midget’ works well in beds and borders and begins blooming when the plant is 6 inches tall. This variety tops out at 12 inches, making it an excellent choice for containers.
• The ‘Burgundy Beauties Mix’ includes plants that produce three colors of blooms: burgundy and white bicolor flowers, solid burgundy flowers, and burgundy flowers with white tips.

Pruning

While not necessary for proliferation, pruning a patch of cornflower can extend its bloom time. To do so, trim the long stems back to the secondary stems once the plants’ first flowering period is over (usually around mid-summer). After the second bloom, cut the plants back to the ground or you can pull them out from the roots to open up space for late-season plantings.

How to Grow Cornflower From Seed

As you might expect from a plant that self-seeds so readily, it’s easy to propagate cornflower from seed. You can collect your own seeds from dried flower heads and store them over the winter until planting time. Or, you can also buy large, inexpensive packets of cornflower seeds.

Here’s how to grow cornflower from seed:

1. Sow seeds in late spring directly into the garden after the last frost. (Don’t be concerned about planting too early; Mother Nature will tell the seeds when to germinate.)
2. Cover the seeds with 12 inch of soil and keep the seedbed watered and moist until germination occurs (usually within 10 days in warm temperatures).
3. Once sprouted, thin the seedlings to increase both blooming and vigor in the plants.

You can also start seeds indoors to ensure early flowering. Do so six to eight weeks before the last expected frost using a seed-starter mix in a seedling tray. Keep the soil moist and warm until the seedlings sprout, and then grow them in a bright location or sunny window until it’s safe to transplant them outdoors.

Potting and Repotting Cornflower

When growing cornflower in pots or containers, make sure to keep the soil on the dry side to mimic pasture conditions. Porous clay or terracotta pots are best. Choose well-drained soil with perlite, or use a soilless medium made from organic material (similar to a cactus potting mix). Deadhead your potted cornflower for a tidy appearance, and be prepared for a short flowering season when grown this way.

Common Pests & Plant Diseases

An annual with a short growing season, cornflower rarely suffers from serious insect or disease problems. Aphids and mealybugs rarely, but sometimes, appear on a crop of cornflower. Control them by reducing the population with bursts of water from the garden hose. Avoid spraying pesticides around cornflowers, even organic ones, as both are harmful to bees and other pollinators that feed on them.

When kept in wet, humid conditions, powdery mildew can occur late in the season, appearing as white spots on the leaves. This fungus rarely kills the plant and treatment is usually not necessary since the plant’s lifecycle is short-lived anyway.

How to Get Cornflower to Bloom

How Long Does Cornflower Bloom?

Cornflower typically blooms for about 10 weeks (from May to mid-July). Seeding the flower on a spaced-out schedule of every two weeks will also extend bloom time.

What Do Cornflowers Look Like and Smell Like?

Cornflower’s lightly fragrant and delicate papery discs are surrounded by bracts that flower atop slim stems of narrow gray-green leaves. Their dense bright blue blooms are well known but this species also boasts several cultivars offering pink, white, and crimson flowers.

How to Encourage More Blooms

Cornflower blooms best in bright and sunny conditions, so make sure to always plant your crop in an area that receives a lot of sun. If your cornflower is not showing blooms due to insufficient light, the only thing you can do is plan better next year and seed them in a sunnier spot.

Caring for Cornflower After It Blooms

Cornflower makes an excellent cut or dried flower. Cut the blossoms in their prime before they begin to wilt.

Deadheading Cornflowers

Increase the bloom time of your cornflowers by deadheading spent blooms. Though deadheading may encourage more flowering, with this particular annual, the practice is not always necessary.

Common Problems with Cornflower

Although rare, cornflower can fall victim to fungal infections when overwatered and crowded. Make sure to adhere to watering recommendations and thin seedlings to allow for proper airflow around the mature plant. In drought conditions, cornflower is prone to wilting, which can cause your crop to fall over and look unsightly. Usually, a good drink is all that is needed to perk them up.