The Centaureas are some of the most graceful flowers to grow in any garden. The flower heads are like showy, ragged thistle blooms of bright red, deep purple, golden yellow and blue. They grow from 2 feet to 3 1/2 feet tall and bloom during the Summer months.
SPECIES. The Golden Knapweed (Ceataurea macrocephala) is perhaps the showiest of all because the thistle-like, golden yellow flower heads are very large. The plant itself is an erect and somewhat spindly grower and the stems are stiff.
The Mountain Bluet (C. montana) has numerous deep blue flower somewhat resembling the annual Cornflower and grows 11/2 feet tall.
The Knapweed (C. dealbata) has flowers which are lilac-pink to white in the center, or a bright red. This species seems to attract the birds when the seed is ripe, thus making it hard to save the seed.
C. babylonica is a whitish perennial with yellow flowers which grows at least 3 feet tall.
Several of the species are known as Dusty Millers; the foliage is white throughout the Summer. C. cineraria has less divided leaves than the other common species C. gymnocarpa, but the leaves are usually whiter.
UTILIZE. Centaureas are used for the perennial border, for pots, baskets and the rock garden. The Golden Knapweed is the largest flowered sort and is most attractive planted among shrubs. Most of these plants produce long stemmed and lasting flowers which are admirable for cutting.
The Dusty Millers have a real place in the garden for there is no contrast so charming as that between the bright colors of most perennials and the gray or whitish leaves of these plants. They may be clipped low as edging plants.
GENERAL. Cetaureas are of very easy culture. They bloom best when planted in an open, sunny position, with any good garden soil. Clip back the Dusty Millers to keep them at the desired height and form. The blooms are not valuable.
PROPAGATION. They are propagated from seeds, although some of the sorts may be readily divided. The Dusty Millers are increased both by seeds and cuttings