Cornflower
Centaurea cyanus
The iconic cornfield cornflower or bachelor's button — a slender, grey-green hardy annual carrying intense-blue (also pink, white, or purple in cultivars), fringed, thistle-like flowerheads from early to mid summer. POWO (Kew) places it native to southeastern Europe, the Balkans, and the eastern Mediterranean, naturalised across much of the temperate world as a cornfield archaeophyte. Honesty matters here: once a common cereal-field weed, the wild cornflower has DECLINED sharply across northern Europe under modern farming and is a genuine conservation concern there, even as it remains a beloved, easy, self-seeding cottage and meadow annual. Its blue florets are edible — a traditional garnish for salads, cakes, and teas. RHS gives several selections the Award of Garden Merit and rates the species fully hardy (H7). A strong nectar plant for bees and butterflies, it also bears extrafloral nectaries that feed ants and other insects.
Climate fit: moderate (56/100)
Border
Pollinator
Edible
Filler
Light
Full sun
Water
Moderate water
Mature size
12-36" tall · 6" apart
Lifecycle
True annual (one season)
Native in Illinois
No
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It is a strong NECTAR plant for honey bees, solitary bees, and butterflies such as painted ladies and red admirals; it also bears extrafloral nectaries that feed ants and other insects.
Cold hardiness
These values are location-based: this location's current hardiness is the baseline, and the 2050 value is a projected future climate for this same location.
Now
Zone 6b
Plotwright
USDA Zone 6b
-5°F to 0°F
Well-suited
Zone 7a
Plotwright
0°F to 5°F
Well-suited
In plain terms: This location has cold winters. Its winters are projected to keep warming through 2050.
✓
Well-suited today and still thriving in 2050.
Heat tolerance
Heat tolerance values are location-based too: heat days today are observed at this site, and the 2050 value projects this same location under a future climate.
Loading AHS heat-zone data for this location...
Where this plant fits
Suitable across 41 ecoregions — 40 climate-resilient through 2070 · 1 suited today. Best matches first.
Appalachian mixed mesophytic forests
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Appalachian-Blue Ridge forests
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Arizona Mountains forests
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Atlantic coastal pine barrens
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Blue Mountains forests
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Canadian Aspen forests and parklands
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Central Pacific Northwest coastal forests
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Central Tallgrass prairie
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Central-Southern Cascades Forests
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Chilean Matorral
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Similar plants
Browse lateral options with similar roles, light needs, size, or native-range overlap; these are not filtered for a better climate fit.
Bellis perennis
English daisy
The classic lawn daisy: a low, rosette-forming perennial with spoon-shaped leaves and white, often pink-tipped ray flowers around a yellow disc on short stems, blooming from spring into autumn. The flowers close at night and in rain — the old "day's eye" — and double cool-season bedding forms such as "Pomponette" and "Habanera" are widely grown. Often written off as a lawn weed, it is in fact a tough, charming, child's-favourite groundcover that flowers for months, thrives in mown grass because it keeps its blooms low, and offers easy early-season nectar and pollen. The flowers and young leaves are edible.
Zinnia elegans
Common zinnia
An old garden-favorite annual native to Mexico, grown for showy daisy-like flowers in nearly every color but true blue — red, yellow, orange, pink, rose, lavender, green, and white. Bushy, leafy plants rise on upright, hairy, branching stems and bloom continuously from early summer to frost. A magnet for butterflies and hummingbirds, and one of the most reliable cut-and-come-again cutting-garden flowers.
Cosmos bipinnatus
Cosmos
A fast, low-maintenance warm-weather annual from Mexico and the southern United States, grown for saucer-shaped, daisy-like flowers (2-4 inches across) with red, pink or white rays around a yellow center. The lacy, threadlike bipinnate foliage gives an airy texture, and the long bloom run from early summer to frost makes it a workhorse for cutting and cottage gardens. It flowers best in lean soil — overly rich, fertile ground produces leafy plants with fewer blooms.
Eschscholzia californica
California poppy
The California state flower — a drought-tolerant southwestern native perennial (grown as annual outside zones 8-10) producing iconic vibrant orange (sometimes yellow, pink, red, or white in cultivars) cup-shaped flowers that open in sun and close at night or in cloudy weather. Naturalizes readily via self-seeding; among the most reliable hot-dry-site wildflowers for borders, meadow plantings, and rock gardens. Family Papaveraceae but unrelated to the opium poppy (different chemistry, no narcotic alkaloids).
Papaver rhoeas
Common poppy
A hairy-stemmed hardy annual of cornfields and disturbed ground, the common poppy bears finely cut leaves and brilliant scarlet, papery, four-petalled flowers — often with a dark basal blotch — in early summer, followed by the iconic pepper-pot seed capsule. This is the remembrance / Flanders poppy. Important and load-bearing: it is NOT the opium poppy (Papaver somniferum) but a different species, and its seeds are NOT the culinary "poppy seeds" of that plant; it contains only mild alkaloids (rhoeadine) and the green plant is regarded as mildly toxic, so treat it as inedible and ornamental rather than a food crop. It is a true annual that self-seeds prolifically and needs open, disturbed soil to germinate — sow it in situ where it is to flower, as it dislikes transplanting. The flowers offer pollen but little nectar, so bees work them for pollen.
Gaillardia pulchella
Firecracker blanketflower
A fast, sun-loving member of the aster family grown as a warm-season annual, Gaillardia pulchella throws a long succession of 2-inch daisy-like flowers from early summer until frost. The ray florets blaze in bands of red and gold around a darker domed center — the firecracker coloring that gives it its name — on a wiry, branching 12-24 inch clump. It is built for hot, dry, sunny ground where richer-fed bedding plants sulk, blooming hardest exactly when summer heat peaks.
Sources & citations
Cite this page
For lesson plans, articles, or research that uses this page. To cite a single upstream fact instead, use its specific source listed below.
Plotwright. (2026, May 17). Cornflower (Centaurea cyanus). Retrieved 2026, June 25, from https://plotwright.com/plants/centaurea-cyanus
Sources for every fact
Every fact on this page traces to a source. 18 fields cited - 18 source-backed.
Plants of the World Online (POWO)
Botanical research database
Backs 17 fields
Identity
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