Cornflower 'Black Ball' Seeds
Dark, dramatic, and impossibly sophisticated—'Black Ball' is the moody, mysterious member of the cornflower family. Despite its name, the colour isn't truly black but rather a deep, sumptuous shade of velvet maroon-chocolate that looks like it has been dipped in dark plum ink. It's the colour of crushed blackberries, of vintage velvet, of old Dutch oil paintings.
This variety transforms a standard cottage border into something modern and elegant. It creates a stunning display when planted with white cosmos or Ammi for a "black and white" look, and adds wonderful depth to hot borders of reds and oranges. Standing tall on silvery stems, 'Black Ball' is a fantastic cut flower—absolutely stunning when tumbled into a vase with other informal blooms. Like all cornflowers, it's incredibly easy to grow, tough as old boots, and produces buckets of flowers all summer long. Beloved by bees and flower lovers alike.
🌿 Understanding the Plant
Centaurea cyanus is a Hardy Annual (H7), meaning it completes its entire life cycle in one growing season and can withstand temperatures down to -20°C. It is a "cool season" flower, meaning it establishes best in the cooler days of spring or autumn.
The 'Ball' varieties produce double, ruffled flowers that are far fuller and more substantial than wild cornflowers. The name Centaurea comes from the centaur Chiron in Greek mythology, who was said to have used the plant to heal his wounds—a nod to cornflower's long history in herbal medicine.
The "Autumn Secret": While most gardeners sow cornflowers in spring, the secret to giant plants with hundreds of flowers is to sow in September. These autumn-sown plants establish a huge root system over winter and flower weeks earlier than spring-sown ones, creating bushier, more floriferous plants. They're incredibly hardy and will sail through British winters without protection.
Historical Interest: Cornflowers were once a common sight in British cornfields, growing as a "weed" amongst wheat and barley. While the classic blue is most famous, 'Black Ball' brings a contemporary, sophisticated edge to this cottage garden classic—perfect for modern planting schemes and Instagram-worthy bouquets.
🌱 Growing Guide
Cornflowers are ridiculously easy to grow and perfect for beginners!
How to Sow:
Sow directly outdoors in Autumn (September) for the strongest plants, or Spring (March-May) for summer blooms. Cornflowers have deep taproots and hate being moved, so direct sowing is always best. Scatter seeds onto raked soil and cover lightly (just 3mm deep). Germination takes 14-21 days.
Where to Plant:
Plant in a spot with full sun and well-drained soil. Here's the key: cornflowers actually prefer lean, poor soil. Do not over-feed them—rich soil leads to lots of leafy growth but weak stems and fewer flowers. They prefer "lean" conditions. Sandy or chalky soil? Perfect!
Ongoing Care:
Support: 'Black Ball' grows tall (up to 90cm). In windy, exposed gardens, give them a little support with twiggy sticks or netting to stop them flopping.
Deadheading: Snip off the dead flower heads regularly to force the plant to keep producing new buds until the frost. Leave some seed heads at the end of the season if you want the plants to self-seed for next year.
📋 Plant Specifications
| Botanical Name | Centaurea cyanus |
| Common Name | Cornflower 'Black Ball' |
| Plant Type | Hardy Annual |
| Hardiness | H7 (Very Hardy - survives to -20°C) |
| Light Requirements | Full Sun ☀️ |
| Height | 75-90cm |
| Spread | 30cm |
| Spacing | Plant 30cm apart |
| Flowering Period | June to September |
| Perfect For | ✂️ Cut Flowers 🎨 Dramatic Arrangements 🐝 Bee & Butterfly Gardens 🏡 Cottage Borders 🥗 Edible Garnish |
| Seeds per Packet | Approximately 200 seeds |
🤝 Beautiful Garden Combinations
Dark flowers need lighter companions to prevent them disappearing into the border—the contrast makes both plants shine:
🌿 Ammi majus (Bishop's Flower): The lacy white umbels of Ammi create a stunning, florist-worthy contrast with the deep, velvety maroon of 'Black Ball'. This is a classic "black and white" combination that looks incredibly sophisticated in both the garden and the vase—like a ready-made professional bouquet. Both are easy hardy annuals that can be autumn-sown together.
🧡 Calendula 'Touch of Red': The burnished orange petals with mahogany-red undersides pick up the dark tones of the cornflower beautifully, creating a warm, rich colour scheme that glows in the late summer sun. Both are easy, reliable plants that bloom for months on end.
📅 Sowing & Flowering Calendar
Sow outdoors in autumn or spring. Flowers from June to September.
💡 Edible Garnish Tip
Cornflower petals are 100% edible! They have a very mild flavour and are perfect for sprinkling over cakes, salads, or floating in summer drinks. The dark maroon petals of 'Black Ball' look particularly striking scattered over white desserts like pavlova or vanilla ice cream, or frozen into ice cubes for a dramatic touch at dinner parties.
🏆 Wildlife Champion
This is a superstar plant for biodiversity. Centaurea cyanus is listed on the RHS Plants for Pollinators list, producing high-quality, easily accessible nectar that attracts bees, butterflies, and hoverflies throughout the summer. The flat, open flower structure makes it particularly valuable for short-tongued bees and beneficial insects.
📖 Want more detailed growing advice?
Read our full UK growing guide for Cornflowers here: Cornflowers in Your Cottage Garden: Growing Guide for UK Climate
- Regular price
-
£2.30 - Regular price
-
- Sale price
-
£2.30
Couldn't load pickup availability
