The Mountain Bluet (Centaurea Montana) Care Guide

The Mountain Bluet, otherwise known as the Centaurea Montana or Mountain Cornflower, Perennial Cornflower, Mountain Bluets, Knapweed, Mountain Knapweed, Bachelor’s Button, Great Blue-Bottle, is a rather well known perennial plant by gardening enthusiasts around the world.

Best known for its low maintenance and moderate growth, this perennial will likely liven up your house (or garden) with its gray-green colored leaves. But, only if you learn how to take proper care of it for it to thrive.

This is why all the topics you need to know in order to achieve this will be covered in this Mountain Bluet Care Guide. Ready? Let’s go!

The basic care guidelines you need to remember for your Mountain Bluet are the following:

  • Water: The Mountain Bluet needs soil that is constantly moist through regular watering.
  • Light: Keep your Centaurea Montana in an environment where it can receive full sun on a daily basis. 
  • Soil: Make sure to keep the Mountain Bluet in soil with well-draining properties, so ideally, one that is made of sand and loam.

That’s it – sunlight, water and soil! The basic 3 fundamentals for all plant care, and with the Mountain Bluet this is no exception. With these three elements, your leafy friend will live healthy and happy.

Scientific / Botanical Aspects

In botanical terms, the Mountain Bluet belongs to the Asteraceae family, the genus Centaurea and the species Montana, hence its scientific (or botanical) name Centaurea Montana (sen-TAR-ee-uh MON-tah-nuh).

As with other Centaurea’s, the Mountain Bluet is a herbaceous plant, which means it will die back to the ground every year. 

Growing Region

The Mountain Bluet is a plant native to Europe.

You might be wondering why your Mountain Bluet’s native region is important. Well, if you know where your plant originally came from, you’ll know which environment conditions it prefers, and with it, knowledge on how to replicate it at home.

With this in mind, the Centaurea Montana will be most used to the heat zones in the 1 – 9 region, as the plant hardiness level falls between 3a, 3b, 4b, 4a, 5b, 5a, 6b, 6a, 7a, 7b, 8b, 8a and the ideal climate zone is between 2, 3, 4, 5, 6, 7, 8, 9, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24.

Growth and Size


In terms of size and growth, the Mountain Bluet is a relatively moderate grower, which makes things somewhat easy for any plant enthusiast.


But, how big does the Mountain Bluet actually get? What should you expect in terms of size? Let’s dive right in…

The Centaurea Montana can grow up to 1′ – 2′ (30cm – 60cm) in 1′ – 2′ (30cm – 60cm) and 1′ – 2′ (30cm – 60cm) in 1′ – 2′ (30cm – 60cm). 

These dimensions make the Mountain Bluet a relatively medium perennial compared to others, so it’s best to keep this fact in mind since it will affect where you want to keep yours at home.

This is why experts recommend keeping an area of approximately 15″ – 18″ (37cm – 45cm) free so the Mountain Bluet can spread to its best extent.


In terms of watering, the Mountain Bluet is a fairly complicated plant to take care of. This is mostly because it has a not so straightforward watering schedule and somewhat regular watering needs.

Specifically, most experts agree that the Centaurea Montana needs soil that is constantly moist through regular watering.

Which is why it is considered a plant with relatively average needs in terms of water. 

As a rule of thumb, you should remember to keep your Mountain Bluet in soil with well-draining characteristics, as these will guarantee the right conditions for your plant to grow and thrive. 

When you consider this, this is why you should aim to choose soil that has moist properties to keep the right moisture levels at all times. 

In our experience, the famous ‘thumb’ or ‘finger’ test is what works best for the Mountain Bluet since with it, you will be able to give it the right amount of water, every time – regardless of the environment or placement where you do decide to keep it.

Soil Mix

As mentioned earlier, the Mountain Bluet prefers to have soil with moist properties at all times, reason why you need to make the soil mix out of sand and loam.

In addition to this, expert gardeners recommend having preferably alkaline, acid or neutral soil.

Light and Exposure

In terms of light & exposure, the Mountain Bluet requires full sun in order for it to thrive under the right conditions. 

Most experts agree that this perennial will do well as long as you keep it in partial to full sun, and it will be able to grow properly.

Specifically, we recommend that you place your Centaurea Montana in little to partial shade (only 2-6 hours of direct sunlight a day), to full and direct sun (more 6 hours of direct sunlight per day).


Being a herbaceous plant, the Mountain Bluet will die back to the ground every year. But, you can expect it to have its ‘prime-time’ during the spring (late), and during the summer (early).


You can expect your Mountain Bluet to flower around the summer months from July to September (summer). In particular, this perennial is well known for its flowers for cutting and showy flowers around the plant enthusiast community.

The Mountain Bluet produces some beautiful blue flowers around this time of year.


The leaves from the Mountain Bluet have a beautiful gray-green color during most of the year.

Attracts, Tolerance and Resistance

The Mountain Bluet is well known for being able to attract butterflies, so keep that in mind when choosing your plant, as you’ll likely end up finding one or another in your garden.

Additionally, it has a special tolerance for dry soil, drought and animals like deer, so don’t worry if any of these come along, your Centaurea Montana will be fine.


Now, let’s talk garden and how your Mountain Bluet will look best in it.

Most Centaurea Montana owners agree that this perennial will look great in most cottage and rustic gardens of all types. Other owners consider that they complement well most gardens of informal and cottage, coastal garden, gravel and rock garden, and in prairie and meadow styles. 

In particular, the Mountain Bluet’s best location within your garden is in beds and borders, others use it for landscaping in a cutting garden,


And we’ve come to an end. Fortunately, that’s everything you need to know about your Mountain Bluet to keep it safe and sound in your garden or home. Enjoy planting!

Martin Duran

Hey y'all! My name is Martin Duran and I am from Cali, Colombia. Since 2018 I have been learning about plants and how to take care of them. Here's is my journey... “The clearest way into the Universe is through a forest wilderness.” ― John Muir

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