Common Knapweed Seeds (Centaurea nigra)

Easy to grow in a range of soils, this hardy perennial adds a splash of colour and long-term biodiversity to any area. its vibrant purple thistle-like blooms provide rich nectar for bees, butterflies, and other beneficial insects throughout the summer.

Key Features:

• Long-flowering native perennial that supports bees, butterflies, and hoverflies
• Ideal for wildflower meadows, verges, borders, and pollinator-friendly planting
• Thrives in poor to moderate soils with minimal car
• Supports biodiversity and encourages beneficial insect life
• Drought-tolerant once established and suited to a wide range of conditions
• Approx. 250 seeds per 1g

Common Knapweed (Centaurea nigra), is a robust UK native wildflower that grows to around 60–80 cm tall. Its deep purple, tufted flowers bloom from June to September, providing a valuable nectar source during the peak pollinating months.

The plant has coarse, upright stems with narrow, lance-shaped leaves, giving it a natural and untamed meadow look.
This perennial thrives in full sun and prefers well-drained soil but is tolerant of a range of conditions, including dry or nutrient-poor ground. Once established, it returns year after year, making it a reliable and resilient addition to rewilding projects, wildlife gardens, and pollinator margins.

Common Knapweed is a key species in traditional hay meadows and is especially beneficial to long-tongued bees and butterflies. It's often used in native wildflower mixes to restore lost habitat and improve biodiversity.

Sow Common Knapweed outdoors in autumn or spring, directly onto prepared soil. Lightly rake the seeds in and firm the soil, do not bury deeply, as light aids germination. Seeds typically germinate within 2 to 4 weeks in suitable conditions.

Choose a sunny or lightly shaded spot with free-draining soil. Once established, Common Knapweed is drought-tolerant and requires minimal upkeep. Avoid using fertiliser, as overly rich soil can suppress flowering.

This perennial will usually flower in its second year, with increasing bloom density over time. Cutting back spent stems in late autumn or early spring helps maintain healthy regrowth.

For garden applications direct sow at 1g/m2. For overseeding existing meadow planting or for new sowings on larger areas sow at a maximum of 2g/m2.

Common Knapweed is essential for wildflower meadows, verge plantings, nature reserves, and rewilding areas. Its nectar-rich flowers attract a wide range of pollinators, including solitary bees, honeybees, and butterflies such as the Marbled White and Meadow Brown.

The seed heads also provide food for finches and other birds later in the season, making it a year-round asset in any wildlife garden or biodiversity-focused landscape.

We offer a flat shipping rate of £5.99.

Garden lawn seed, wildflower seeds, and wildflower seed mixtures are typically dispatched within 1 to 3 working days.

Products from our agricultural, landscaping, and equine ranges may be shipped separately as they are mixed to order.

We aim to ensure customer satisfaction with all products supplied. If you experience any issues with your order, please contact us at info@kentseeds.co.uk within 5 working days of the dispatch date, quoting your order number and a detailed description of the issue.

Read our full Delivery & Returns policy here.

Q1: When is the best time to sow Common Knapweed?
A: The ideal times to sow are in autumn (August–October) or spring (March–May) directly into prepared soil.

Q2: How long does it take Common Knapweed to flower?
A: As a perennial, it usually flowers in the second year after sowing, with blooming from June to September.

Q3: Can I use Common Knapweed in a formal garden?
A: While primarily used in wildflower or naturalistic settings, it can be incorporated into informal borders or prairie-style plantings for pollinator support.

Q4: Is Common Knapweed invasive?
A: No, it's a well-behaved native species that supports wildlife and coexists well with other meadow plants when used at the correct sowing rate.