Knapweed Garden Gem or Invasive Weed?
Centaurea macrocephala also called Knapweed is a tall perennial plant in the cornflower family. Even wikipedia can’t decide about the scale and desirability of the Centaurea family. As with many families there are good and bad and this species seems fine in my garden.
Growing Centaurea macrocephala
- At 3′ to 5′ high this bold plant is ideal for providing vertical interest in a sunny, well-drained herbaceous border.
- The golden-yellow thistle like flowers are on stiff stems from July to late summer and mid-green, lance-shaped leaves are followed by attractive seed heads.
- The flowers are attractive to butterflies bees and many insects as you can see. This and the attractive seed heads make this variety an eco-friendly plant to grow.
- When dried the seed heads are excellent for use in flower arrangements.
- Other Centaureas are blue and purple and can make fine cottage garden plants.
- Avoid Spotted Knapweed that are invasive and ugly cousins Centaurea biebersteinii , Centaurea maculosa and Centaurea maculosa subsp. micranthos
More insects on a Purple Centaurea that flowered in June.