C. dealbata produces rose-purple flowers and is also perennial. C. montana, which is commonly known as the Perennial Cornflower or Mountain Bluet, only grows 2 feet tall. The colors range from lavender-blue, rose, pale yellow or white among the different varieties of this plant. The hardy perennials thrive in regular, well-cultivated garden soil. They may be planted in the spring or autumn.
Annual Cornflowers are great for growing in pots or beds in the greenhouse.
They need a lot of sun and a night temperature of 45-50 degrees. May. When the seedlings are about 2 inches high, plant them in a nursery border and set them in their permanent positions the following spring or fall. They'll bloom the following year after sowing the seeds. These are vigorous plants, so they should be set 2-4 feet apart depending on their expected height. Those that have silvery or whitish leaves should be propagated by cuttings that are taken in late summer or early fall.