Mountain bluet is just one name used for Bachelor Buttons and the Centaure family of plants.
Centaurea is a composite or member of the daisy family and with over 450 members of Centaurea to chose from, there is one for almost every sunny spot in the garden.
Here’s how to grow them.
- Sun: full sun is best
- Bloom Color: blue and shades of blue-maroon, yellow
- Bloom Time: early summer to mid-summer for about 4 weeks or shorter
- Height: 18-36 inches depending on species
- Width: 18-24 inches depending on species, plant 18 inches apart
- Propagation: seed often self-sowing to become a nuisance
- Growing Care Tips: Not many, this is a fool-proof plant. If your garden is too rich and well fed, this plant is going to flop around and may require staking.
- Hardiness: USDA 4
- Best Soil: well-drained but almost anywhere
- Potential disease problems: none that can’t be outgrown
- Potential insect problems: no substantial
- Use: cut flowers, perennial border, wild areas
Start Your Own Seed
Start the annual mountain bluet plants by direct sowing in the garden; they grow best in this way as they get too tall too fast in the greenhouse. They are also cheaper to purchase in a pack of seed rather than a starter pack.
Bachelor buttons will bloom from seed in their first year if started in January but will bloom the second year if started in the garden.
Cover the seed very thinly with soil so you just lose sight of the seed – do not bury it deeply or germination will not happen. Keep them moist and you can expect seedlings within a month of the ground turning warm.
Sow thinly but if you get them too thick – only 12 to 18 inches apart – you can transplant extra plants to other spots in the garden. Try to do this when the seedling has four to six true leaves and take as much soil with the young roots as possible.
Water the transplants thoroughly and regularly every day to two days until they start developing new leaves.
This is truly a self-sowing thug in many gardens. Left unchecked C. montana will form a solid mat of blue in early summer. Quite attractive but never met a plant it didn’t like to compete against.
Do put it into a wild area and allow it to thrive. The others have not been as bad.
- If you sow the seed indoors in January, it will bloom in its first year. This is assuming you give it all the light it requires and fed properly.
- If you mulch your garden, this plant may not self-sow well. The large seed tend to be noticed by birds (who will strip a plant out very quickly) and mice/chipmunks who forage around the base of the plant. A mulch simply makes it harder for the seed to survive.
This is the best known of the perennial species and it is known by several common names, Mountain Bluet, Perennial Bachelor Buttons, and even Perennial Cornflower. Native to Northern Europe, Cornflower
‘Gold Bullion’ is a yellowish-leaved variety and the blue blooms form a great contrast. I had this plant for two seasons and then lost it. It wasn’t a strong grower, unlike the species.
is a mid-sized 24-inch species with pink/maroon flower heads, native to Eastern Europe. Interesting but I was never impressed with it my garden. I obtained some wild seed and it was easily grown. It didn’t self sow as wildly as the C. montana did. Ho-hum. Didn’t go looking for more after I moved and left it in that garden.
Plant Legends and Name
While it has nothing to do with the name Mountain Bluet, as a kid, I always thought that centaurs were interesting creatures. Half horse and half man, these offspring of King Ixion were a warlike, passionate bunch constantly fighting and warring with themselves and the humans that lived nearby. These were lusty creatures, stealing wives and whacking each other with tree branches – just the kind of activity to fire imaginations and kindle legends.
However, rather than his warlike cousins, the peaceful Chiron is the best known of the centaurs. Chiron was the son of the god Cronus (who liked to wander around disguised as a horse) and the sea nymph Philyra (who evidently had a thing about horses) and lived near Mount Pelion in Thessaly. He is known as
As a reward for his service and compassion and giving up his life, the gods turned him into the constellation Sagittarius.
Now, that’s the long way around explaining that the plant Centaurea is also named after Chiron the centaur, and we also know it as Mountain Bluet. As you’ll see,
Resources to Find Material Mentioned on This Page
Mountain bluet seeds and plants – note there are both annual and perennial seeds of Centaurea here