Centaurea jacea aka Brown Knapweed

Taxonomy

Centaurea jacea, also known as brown knapweed or brownray knapweed, is a herbaceous perennial plant native to Europe that grows to be 10-80 centimeters tall. It flowers mainly from June to September and can be found in dry meadows and open woodlands. The flower heads of brown knapweed always appear rayed, forming a more open star rather than a brush-like tuft, unlike the black knapweed with which it is often hybridized. Centaurea ×moncktonii is a fertile hybrid between black knapweed and brown knapweed. Brown knapweed has lance-shaped or shallowly lobed leaves that become smaller up the stem and can out-compete native vegetation, reducing biodiversity and available forage species. It can invade open forests, grasslands, and prairies. The plant is often introduced to North America as an ornamental species. Brown knapweed likes soil that is well-draining and needs regular watering to thrive. It does best in long-lasting, direct light and should be less than 1 foot from a window. In the first year of growth, brown knapweed only has leaves on the ground in a rosette and grows a stalk and blooms in the second and subsequent years. The stems are rigid and may have purple stripes. The flowers of brown knapweed are 15-25 cm wide and have bracts that are modified leaves underneath the petals. The bracts usually have a distinctive papery margin and are light brown. The fruits usually don't have a plume or bristles. Brown knapweed can hybridize with black knapweed, which creates plants that look slightly different from either parent species.

Common names

Brown Knapweed, Brownray Knapweed

How to care for Brown Knapweed

Difficulty

Even if you don't have a green thumb, you can successfully care for Brown Knapweed due to its easy-going nature.

Water

Brown Knapweed should be watered regularly, allowing the soil to dry out between waterings.

Soil

Brown Knapweed loves a well-draining soil. Perlite and vermiculite help with drainage, while coco coir adds organic matter, so a good potting soil mix will have all three. You can improve store-bought soil by adding some perlite to it.

Lighting

To ensure optimal growth, the Brown Knapweed prefers bright diffused light for 6-8 hours each day. Insufficient light can result in slow growth and leaf drop, so it's important to find a well-lit location for this plant. Place it near a window, within a distance of 1 meter (3 feet), to enhance its potential for thriving.

Dormancy

During the wintertime, it's common for Brown Knapweed to go dormant and their growth may slow down, so waterings should be spaced out more.

Toxicity

Ploi does not possess verified information regarding the toxicity of this particular plant. In the event that you, a member of your family, or a pet ingests plant material with an unclear toxicity level, it is highly recommended to seek the advice of a medical professional.

Fertilizer

The Brown Knapweed should be transferred to a new pot once it has increased in size two-fold, or on an annual basis, whichever occurs earlier. Replacing the soil with fresh potting soil containing all the necessary nutrients, is sufficient enough to support the growth of the plant, thus avoiding the need to use fertilizer. It's important to note that plants derive their energy from the sun and not fertilizer.

Region of origin

Brown Knapweed’s native range is Europe. Naturalized in Britain.


More info:
Wikipedia