Centaurea Cyanus: Best Practices for Growing the Cornflower

Grown from seed each year, Centaurea Cyanus can easily add a splash of color to any garden bed or window box. It’s a beautiful plant with large, colorful flowers.

Pronounced [sen-TAR-see-uh SY-an-us], the Centaurea Cyanus is also called bachelor’s button or cornflower. It’s part of the Asteraceae family and native to parts of Europe.

The plant was often found growing as a weed in cornfields, which led to the common name. While it’s rarely found in its native habitat, the cornflower seeds are readily available.

This annual plant is easy to grow and care for throughout the year and produces flowers all summer, making it a great choice for brightening a garden.

To grow this former wildflower, some standard plant care steps need to be followed.

cornflower is a summer-bloomerPin

Caring For Centaurea Cyanus

The cornflower is a summer-bloomer that can reach up to three feet tall. While it can reach up to three feet tall, it often grows to just one foot when placed in a pot.

As an annual, it’s often grown from seed. However, it’s also possible to find small plants at nurseries early in the season. The plant is rather bushy and grows lance-shaped leaves and thin stems.

What Do Cornflowers Flowers Look Like?

The large flowers are the best feature of this plant. When the seeds are sown in early spring, the plant flowers all summer. There is no discernable fragrance.

The flowers appear at the tops of the long stems. While the cornflower blue is the most common variety, the plant also comes in shades of red, purple, white, and pink. There is even a variety that showcases all these colors.

What Are Bachelor’s Button Light and Temperature Light Requirements?

These plants can be grown almost anywhere. They are suited for USDA hardiness zones 2 to 11, which is an extreme range of regions.

As an annual, winter temperatures are less of a concern. The plant just needs to last through the warmer months when it can show off its flowers.

Cornflower grows best in full sun. In shaded areas, it’s less likely to get the nutrition it needs to grow large, healthy flowers.

How Often To Water and Fertilize Centaurea?

Throughout the growing season, ensure that the plant has plenty of water, especially in warmer regions.

What is The Best Soil For Centaurea Cyanus Plants?

Standard potting soil works fine for the bachelor’s button. The soil should offer good drainage.

When using a planter, drainage holes are needed to keep the soil from retaining too much moisture.

TIP: If your planter doesn’t have drainage holes, add a layer of gravel to the bottom of the planter. Excess water will drain through the soil and into the gravel.

Does Centaurea Need Any Special Grooming or Maintenance?

As the flower heads wilt, trim them off to encourage more growth before the end of the season.

The cornflower is an annual and won’t live past the year. When it dies out, remove the old growth or leave it in place and allow it to naturally decompose.

The dead flowers can help add nutrients to the soil when grown in a garden bed.

How to Propagate Bachelor’s Button

Propagating the plant is possible with seeds. The seeds can be sown in early spring or late summer.

When sown in the spring, they should flower in the summer. If sown in the summer, the plant may flower during the winter, in warmer regions.

When sowing the seeds, spread the sowing out. After sowing a handful of seeds, sow another handful two weeks later.

The seeds may also be started in a seed tray or pan. This also allows you to start the seeds early. However, they should not be transplanted outdoors until there is no danger of frost.

After the seedlings sprout, they can be thinned to prevent overcrowding. Crowding causes the plants to fight for nutrition, resulting in less growth.

Helpful Pests or Disease Tips For Centaurea Cyanus

The plant is not toxic, but it’s considered invasive in some regions, as it grows and spreads quickly.

Pests are also not a problem, as the plant doesn’t last very long.

When a white powdering coating is detected on the leaves, the plant is likely suffering from mildew.

The affected parts should be trimmed away to keep the issue from spreading. Spray the surviving areas with fungicide and limit watering.

If brown spore-like growths appear, the plant is suffering from rust. The affected areas still need to get trimmed away. If the issue spreads, the entire plant may die.

Suggested Uses For Centaurea

As it thrives in almost any climate, grow the plant indoors or outdoors. The plant is easy to grow in a container, garden bed, or window box.

It can add color to a porch or patio or bring more depth to a perimeter garden.

The larger varieties are best suited for outdoor growth while the smaller varieties work well in planters and window boxes.