Centaurea Imperial Planting Instructions


Centaurea imperialis, also known as royal sweet sultan, is a flowering annual plant and a hybrid of C. moschata and C. margaritas. C. imperialis is a variety of cornflower that blooms in 2-inch, thistle-like flowers in white, lavender, pink and yellow. If you are looking for a fragrant addition to your cut flower garden, consider the C. imperialis. Sow the seeds in April for July blooms.

Step 1

Choose a planting location for the Centaurea imperialis that gets full sun.

Step 2

Dig into the planting bed to a depth of 8 inches, turning and crushing the soil with the gardening fork.

Step 3

Add a 3-inch layer of compost to the soil and mix it in to a depth of 8 inches.

Step 4

Pour lime onto the soil and mix it to a depth of 8 inches. Agriculturists at Washington State University suggest that the amount of lime to add depends upon the type of soil in your garden. If you have sandy soil, add 4 lbs. of lime. If the soil is loamy, add 6 lbs., and if you have clay soil, add 8 lbs. of lime. These amounts apply to every 100 square feet of garden space.

Step 5

Rake the soil smooth after amending. Plant the Centaurea imperialis seeds 1/4 inch into the soil, and 12 inches apart.

Step 6

Water the area with the fine mist setting on the hose and keep the planting bed moist, not soggy.

Things You'll Need

  • Gardening fork
  • Compost
  • Lime
  • Rake


  • Washington State University: Soil Preparation and Garden Layout
  • Fritz Bahr's Commercial Floriculture: A Practical Manual For the Retail Grower
  • ‭"‬California Master Gardener Handbook‭;" ‬Dennis R.‭ ‬Pittenger‭; ‬2002
Keywords: plant Centaurea imperialis, Centaurea imperialis propagation, growing Centaurea imperialis

About this Author

Victoria Hunter, a former broadcaster and real estate agent, has provided audio and written services to both small businesses and large corporations, worldwide. Hunter is a freelance writer specializing in the real estate industry. She devotes her spare time to her other passions: gardening and cooking. Hunter holds a Bachelor of Arts in English/creative writing.