Perennial Cornflower Centaurea montana
ABOUT
Centaurea montana, commonly known as perennial cornflower, mountain bluet, or mountain knapweed, is a flowering plant with distinctive and attractive features. Its appearance is marked by tufts of gray-green to green foliage that form a lush base for the flowering stems. The leaves are lance-shaped and sometimes have a slightly hairy texture. The blooms of perennial cornflower are noteworthy for their intense blue color, often with a violet tint, which makes them stand out in garden settings. Each flower is composed of a central cluster of tubular florets, which can sometimes appear almost thistle-like due to their shape. Surrounding these are larger, showy bracts that are often mistaken for petals. These 'petals' are typically a deeper blue with a spiky, fringed margin, giving the flower a ragged but ornamental look. The flowers are borne singly atop slender stems that rise above the foliage, creating a layering effect that adds depth to the plant's visual presence in a garden. When in bloom, perennial cornflower attracts various pollinators, including bees and butterflies, eager to visit the nectar-rich flowers. The blooming period of this plant brings a splash of color that is both appealing to the eye and beneficial to local ecosystems. After flowering, the plant forms seed heads that are somewhat fluffy, a characteristic that can add textural interest to the garden even after the main blooming season has passed. Overall, perennial cornflower is a charming and hardy addition to borders, wildflower gardens, or as an accent plant, admired for its vibrant blue flowers and relatively low maintenance requirements.
About this plant
NamesFamily
Asteraceae
Synonyms
Mountain Cornflower, Mountain Bluet, Perennial Cornflower, Great Blue-Bottle, Mountain Knapweed
Common names
Cyanus montanus, Centaurea triumfettii subsp. montana, Jacea montana.
ToxicityTo humans
Centaurea montana, commonly known as perennial cornflower, is not widely recognized for its toxicity to humans. There are no well-documented cases of poisoning from the ingestion of this plant, suggesting that it is generally considered safe. However, as with many plants, individual sensitivities or allergies could potentially cause reactions in some people.
To pets
Perennial cornflower is also not widely known to be toxic to pets such as dogs and cats. There appears to be no significant evidence indicating that the ingestion of Centaurea montana is harmful to pets. However, pet owners should always exercise caution and prevent pets from eating plants not intended for consumption, as individual animals might have different sensitivities or allergic reactions.
CharacteristicsLife cycle
Perennials
Foliage type
Deciduous
Color of leaves
Green
Flower color
Blue
Height
1-2 feet (30-60 cm)
Spread
1-2 feet (30-60 cm)
Plant type
Herb
Hardiness zones
3-8
Native area
Europe
Benefits
General Benefits- Attracts Pollinators: Centaurea montana, commonly known as mountain bluet, is known for its ability to attract bees and butterflies, which can help pollinate gardens.
- Low Maintenance: Mountain bluet is a hardy perennial that requires minimal care once established, making it a good choice for gardeners seeking low-maintenance plants.
- Growth Habit: It forms clumps and can be used to fill in gaps and create a lush, full garden.
- Drought Tolerance: Once established, mountain bluet has good drought tolerance, making it suitable for xeriscaping and less water-intensive gardening.
- Long Blooming Period: Mountain bluet has a prolonged flowering period from late spring to early summer, providing a long-lasting splash of color to the garden.
- Deer Resistance: The plant is generally resistant to deer, which helps prevent it from being eaten in areas where deer are prevalent.
- Visual Appeal: Its striking blue flowers add a vibrant touch to any garden setting, and its silvery-green foliage provides a unique texture contrast.
- Aesthetic Combinations: The plant pairs well with other perennials, allowing for beautiful garden designs and combinations.
- Soil Adaptability: Mountain bluet can adapt to a wide range of soil types, although it prefers well-draining soil.
Medical Properties- Anti-inflammatory: Centaurea montana has been traditionally used for its anti-inflammatory properties to help reduce swelling and inflammation.
- Astringent: The plant has astringent qualities, traditionally used to tone the skin and mucous membranes and to reduce bleeding from minor abrasions.
- Diuretic: It has been said to possess diuretic effects, helping to promote the production of urine and increase renal clearance.
- Choleretic: The plant is known to stimulate the production of bile, aiding in digestion.
- Mild antiseptic: Centaurea montana has been utilized for its mild antiseptic properties to help prevent infection and promote healing in minor wounds.
Air-purifying QualitiesThis plant is not specifically known for air purifying qualities.
Other Uses- Centaurea montana, commonly known as mountain bluet, can be used as a natural dye for fabrics, providing a range of colors from yellows to greens depending on the mordant used.
- In the language of flowers, mountain bluet can symbolize delicacy and patience, making it a poetic addition to "message" bouquets.
- With its striking blue flowers, mountain bluet serves as an ornamental addition to pressed flower crafts, such as bookmarks and framed art.
- As a beneficial companion plant, mountain bluet can attract pollinators like bees and butterflies, supporting the health of gardens and ecosystems.
- The dried petals of mountain bluet can be used in potpourris to add color and a subtle, mild scent, enhancing the aesthetic of indoor spaces.
- Mountain bluet can be planted as part of a natural fence or border, utilizing its growth habit to create privacy or mark boundaries in a garden.
- Due to its resilience, mountain bluet can be used in soil erosion control projects, helping to stabilize soil in at-risk areas.
- Mountain bluet can be incorporated into educational activities, teaching about native plant species and the importance of biodiversity.
- When dried and woven, the stems and foliage of mountain bluet can be used in the creation of rustic wreaths and other decorative items.
- Gardeners can propagate mountain bluet by division or seeds, making it a practical plant for sharing among gardening friends and communities.
Interesting Facts
Feng ShuiThe Perennial Cornflower is not used in Feng Shui practice.
Zodiac Sign CompitabilityThe Perennial Cornflower is not used in astrology practice.
Plant Symbolism- Love and Devotion: Centaurea montana, commonly known as Mountain Cornflower, often symbolizes love and devotion due to its vibrant blue color which is traditionally associated with fidelity and strong emotions.
- Hope: The bright appearance of the Mountain Cornflower is also seen as a symbol of hope, representing a wish for positive outcomes and happiness in the future.
- Rejuvenation: As a perennial that returns each spring, the Mountain Cornflower symbolizes rejuvenation and the ability to bounce back from challenges, embodying the cycle of renewal.
- Healing: Historically, the plant was used for its medicinal properties, and thus it can symbolize healing, both physically and emotionally.
- Overcoming Obstacles: Growing in mountainous areas, the Mountain Cornflower can represent resilience and the ability to thrive in difficult conditions, symbolizing the overcoming of obstacles.
WaterFor Bachelor's Button, also known as Centaurea montana, watering should be done thoroughly to keep the soil consistently moist but not waterlogged. During the growing season, water the plant when the top inch of the soil feels dry to the touch, which typically equates to once a week. Use approximately 1 gallon of water per square yard every week, adjusting for rainfall. In hotter temperatures, you may need to water more frequently to prevent the soil from drying out. Decrease watering in the winter months when the plant is dormant, ensuring you only keep the soil from drying out completely.
LightBachelor's Button thrives best in full sun to partial shade conditions. The ideal spot is where the plant can receive at least 6 hours of direct sunlight daily, which will promote vigorous growth and abundant flowering. If you're planting in hotter areas, some afternoon shade can help protect it from intense heat.
TemperatureFor the robust Bachelor's Button, the ideal growing temperatures range from 60 to 75 degrees Fahrenheit. This hardy perennial can withstand minimum temperatures down to around 0 degrees Fahrenheit but may need protection in colder climates. It generally performs well within the USDA hardiness zones 3 to 8, which correspond to these temperature ranges.
PruningTo encourage healthy growth and flowering, prune Bachelor's Button after the initial bloom has faded. Deadheading, or removing spent flowers, will stimulate a second flush of blooms. Pruning can be done every few weeks, or as needed, throughout the flowering season. The best time to cut back the entire plant is in late autumn or early spring.
CleaningAs needed
SoilThe best soil mix for the Perennial Cornflower (Centaurea montana) should have good drainage with a mix of loamy soil, peat, and sand or grit. The soil pH for this plant should be slightly acidic to neutral, ranging from 6.1 to 7.5.
RepottingPerennial Cornflower (Centaurea montana) is typically not repotted often as it is grown outdoors; divide clumps every 2-4 years to maintain vigor.
Humidity & MistingPerennial Cornflower (Centaurea montana) prefers average humidity levels and does not require special humidity considerations.
Suitable locationsIndoor
Ensure ample sunlight and good air circulation indoors.
Outdoor
Plant in well-drained soil with full sun to partial shade.
Hardiness zone
3-8 USDA
Life cycleCentaurea montana, commonly known as mountain cornflower, starts its life cycle as a seed, which germinates in early spring when soil temperatures rise and moisture is available. Once the seed germinates, it develops a root system and a rosette of basal leaves, entering the vegetative growth stage. The plant then sends up stems and produces its distinctive thistle-like blue or violet flowers primarily in late spring to early summer, which are pollinated by insects such as bees. Following pollination, the flowers develop into seed heads, dispersing seeds either by wind or through contact with animals, thereby completing the reproduction phase. During the late summer and autumn, the plant may enter a period of dormancy, especially in colder climates, where top growth dies back and the plant overwinters as rootstock or seeds. With the return of warmth in spring, the cycle resumes as existing plants regrow from the rootstock and new plants sprout from seeds.
PropogationPropogation time
Spring-Early Summer
For the perennial cornflower, also known as Centaurea montana, the most popular method of propagation is by division. This is typically done in either spring or early fall. To propagate by division, carefully dig up an established clump of perennial cornflower and gently separate it into smaller sections, ensuring that each new section has a portion of the root system intact. Replant these divisions immediately at the same depth they were growing at before, spacing them about 12 to 15 inches (30 to 38 centimeters) apart to allow sufficient room for growth. Water the new plantings thoroughly to help establish the roots. Divisions will usually take root quickly and continue to grow, producing flowering plants that resemble the parent.
