Centaurea cyanus
Bachelor's Button
Common names: Cornflower, Blue Cornflower
At a glance
- Light
- Full sun
- Pot size
- from 10 l
- Lifespan
- Annual
- Hardiness
- Cold damage below −10 °C
- Water need
- Low
- For children
- Well suited
- Origin
- Native to Germany
Photo: TeunSpaans · CC BY-SA 3.0 · Source
This description was machine-translated.
Description
The cornflower displays a distinctive cornflower blue that brings a touch of summer meadow to the garden. This annual wildflower blooms from June to August, is drought tolerant, and attracts bees and bumblebees. Its edible flowers can be used to garnish salads and summer bowls.
Care instructions
Sow the cornflower directly into the garden from March in a sunny, somewhat sparse location, no fertilized soil is needed. A fall sowing in September produces especially vigorous plants and early flowering. Water sparingly; the plant tolerates dryness well. Deadhead spent flowers to prolong blooming into late summer.
The care notes were machine-translated from German.
Garden year
SowingMar–May, Sep
HarvestJun–Aug
Germination
- Soil temperature
- from 8 °C, ideally 18 °C
- Days to sprout
- 7 to 14 days
- Light
- Needs darkness to sprout
- Sowing depth
- 1 cm
- How to start
- Sow straight into the bed
Soil & site
Soil pH
Soil type
sandy, loamy, well-drained, lean
Give the cornflower loose, well-drained sandy or loamy soil. It does not tolerate waterlogging. A poor, rather lime-free site is ideal; it tolerates slightly chalky and nutrient-poor soils well, while on very rich, freshly fertilised beds it runs to excessive foliage and flowers more weakly.
Feeding
Light feeder
Months
Apr–May
In spring before sowing, work in at most a thin layer of mature compost shallowly. That is usually enough for the whole season. On garden soil that is already rich in nutrients, do not fertilise at all, because over-fertilising encourages leaf growth instead of flowers. Only on very poor sandy soils does some horn shavings help as an organic nitrogen source before sowing.
Overwintering
The cornflower is an annual and dies in winter. You cannot overwinter the plant itself, and there is no need to. In autumn, leave a few faded heads standing and it will seed itself; alternatively, harvest ripe seeds (heads brown and dry) and store them cool, dark and dry until sowing from March. Direct sowing in autumn (September/October) also works, because the seeds are frost-hardy and germinate early in spring.
Propagation
Methods
- From seed
The cornflower is an annual and is propagated exclusively by sowing. You have two sowing windows: direct sowing in early spring (from March to late April, as soon as the soil can be worked) or autumn sowing (August to September), where the seeds overwinter in the soil and germinate earlier the following year. Scatter the seeds thinly on loose, shallowly raked soil, cover them only lightly, about half a centimetre deep, and press them in gently. Keep the soil evenly moist during germination; germination usually takes one to two weeks. In the garden, the cornflower reliably seeds itself if you let a few flower heads ripen and dry. You collect your own seed once the heads are brown and dry, and keep it dark and dry. Starting indoors in pots from mid-March is possible; plant the young plants out after the Ice Saints (mid-May). Cornflowers hardly tolerate root disturbance, though, so direct sowing is usually the easier and more reliable route.
Companion planting
Companion planting is partly traditional gardening lore. Where the reason is known, it is given.
Some of these explanations were machine-translated.
For your garden
Grow Bachelor's Button yourself
Gartenkern tells you when frost is coming, when to sow and when to harvest, for your location.
Free, no time limit
Notes from real gardens
What other gardeners have written down about this variety, anonymous and voluntary.
No notes shared yet. Will you be the first to write one down?