Cornflower (Centaurea cyanus) is a sturdy, drought-tolerant annual that will grow in poor, dry soil with very little care. Also known as bachelor’s button, cornflowers were originally blue, but the plants are now available in a variety of colors, including red, white and pink. The fuzzy foliage has a grayish-green appearance. The colorful blooms appear in March and usually last until the middle of May. Cornflowers are often used in dried flower arrangements, because the dried blooms retain their shape and bright color.
Purchase young cornflower bedding plants at a local nursery or garden center. Look for compact plants with buds but no open flowers. Avoid long, leggy plants and plants that have wilted, yellowing leaves.
Prepare a sunny spot for your cornflowers, as the plants will do best with at least six hours of sun per day. If you live in a desert climate, plant the cornflowers where they will be in shade during the afternoon. Spread a 1- to 2-inch layer of compost or aged manure over the top of the soil, then spade the soil to a depth of 6 to 8 inches.
Use a trowel to dig a hole for each cornflower plant. The hole should be two to three times wider than the cornflower’s root ball. Place the cornflower plant in the hole, planted at the same soil depth it was planted in the nursery pot. Planting too deeply can cause the cornflower to rot. Allow 10 to 12 inches between each plant.
Water the cornflower plants thoroughly immediately after planting and keep the soil moist until you see new growth, which indicates that the roots are established. Thereafter, water cornflower infrequently, only when the soil is dry. Cornflower is drought-tolerant and doesn’t do well in wet soil.
Pinch off wilted blooms so that the cornflower will continue blooming as long as possible.
Cornflower seeds can be planted directly in the garden in early spring. Plant the seeds about 1/2 inch deep, then keep the soil moist until the seeds germinate, which usually takes about a week. Thin the cornflower seedlings when the seedlings are 2 to 3 inches tall. Allow 6 to 12 inches between each plant.