Centaurea montana or “Mountain bluet” flowers from late spring to early summer. The flowers are fringed in an intense violet-blue with deep purple centres and most attractive, very deeply cut petals which can be up to 7,5cm (3in) across, and blue-greyish, lance-shaped leaves.

Native to the meadows and woods of the mountains of Europe, it is drought resistant and because of this, they also do well in containers, where the soil may dry out quickly. It is very easy to grow from seed and an excellent garden plant as well as cut flower.

The origin of the word bluet is from France. The term bachelor’s-button refers to the long-lasting quality of the flower when it is cut and placed in the buttonhole of a suit or shirt; decades ago, bachelors sported the flower when they went courting.

Sowing: Sow February to May or September to November
Sow seeds in about one month before you want to plant the seedlings outdoors

Sowing Indoors:
Fill individual peat pots, seed-starting flats or cells, or 7cm (3in) pot with a commercial seed-starting mix. Moisten the mix and let it drain.
Sow the seeds in rows in the flats. Sow 3 to 4 seeds per pot and cover the seeds with a 1cm (½in) layer - centaureas need darkness to germinate. Use a fine spray to moisten the top.
Cover the containers with clear plastic to keep the mix moist while the seeds are germinating and place in a warm location 16 to 22°C (60 to 70°F). Germination of perennial cornflowers takes 3 to 4 weeks.
When the seedlings emerge, remove the plastic covers and put the pots in a sunny location or under grow-lights. Water as needed to keep the mix moist (not soggy).
When seedlings are about 5cm (2in) tall and have at least one pair of true leaves, snip off all but the strongest plant in each pot at soil level. (The first set of leaves is known as cotyledon leaves—they usually do not resemble the true leaf shapes of the plants). Fertilise the seedlings once while they are growing indoors with a weak water-soluble fertilizer.

Transplanting:
Transplant on a calm, cloudy day, so the plants can begin to get acclimatised before having to contend with sun and wind. Although they are not too particular about fertility, you may want to dig some compost or dried manure into the soil before planting: a 2 to 5cm (1 to 2in) layer should do.
Plant in full or partial sun in any average soil. Give them room to spread, space about 60cm (24in) apart. Place them in the mix at the same level they were growing originally. Water the planting well.

Cultivation:
Fertilise the plants monthly with a balanced fertiliser or use a slow-release plant food at transplanting time. Water infrequently; Centaureas are drought tolerant, and the stems actually get rather floppy if the soil is too moist.
Remove spent flowers to keep the plants producing new blooms.
Division is usually most successful while plants aren’t in active growth in spring or autumn. Keep well-watered afterwards.

Plant Uses:
Flowers Borders and Beds, Patio/Container Plants, Wildflower Gardens or Wildlife Gardens,
Cut or Dried Flower. Bee plant, First Year Flowering

Cut and Dried Flowers:
Freshly cut blooms last four to five days.
Cut the blooms in early morning when they are half open and strip the lower leaves from the stems.
To dry, pick them in late morning or in the afternoon. Select flowers that have just opened or they will drop their petals when dry. Air-dry the flowers: tie in bunches and hang upside down in an airy, dark place for two to three weeks.