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Plains coreopsis

Joanna Boisse / Wikimedia Commons - CC BY-SA 4.0

Plains coreopsis

Coreopsis tinctoria

The first thing to settle about plains coreopsis is the thing seed racks are vaguest about: it is an ANNUAL. Missouri Botanical Garden types it that way without hedging, the Lady Bird Johnson Wildflower Center calls it an annual in its first line, and the plant germinates, flowers, sets seed and dies inside one season. That single fact separates it from the other two coreopsis in this group. Lanceleaf coreopsis and largeflower coreopsis are true perennials that gardeners routinely expect to be long-lived and that are not quite: MBG says lanceleaf needs dividing every two or three years in a border to stay robust; threadleaf coreopsis, already in this catalogue, is the one that genuinely persists. Plains coreopsis persists differently - not as a plant but as a seed bank. It self-sows heavily, and a stand that looks permanent after five years is five generations, not one plant, which is why it is the coreopsis for a meadow sowing and the wrong one for a slot in a border where something has to be there next April. What you get for accepting that is the best flower in the genus for the money. Solitary daisies one to two inches across, seven to nine bright yellow rays each painted maroon at the base around a red-brown disc, carried in quantity on wiry branching stems above finely cut foliage. MBG rates it showy and good for cutting, lists no serious insect or disease problems, and puts its maintenance at low. It is the plant behind most of the yellow in a roadside wildflower mix. Two cautions belong next to that. It self-seeds hard enough that MBG recommends deadheading specifically to prevent it, and it has naturalised across nearly fifty territories outside its home range, from Britain and Poland to Japan, Java and Fiji - so treat spare seed as something to bin rather than scatter. And the two best sources disagree about water: MBG grows it dry to medium and calls it drought tolerant, while the Wildflower Center rates its water use HIGH and says the good years are the wet ones. Both are describing the same plant honestly, and the record below explains why.

Native: 46 US states + 6 CA provinces

Climate fit: broad (98/100)

Pollinator

Filler

Border

Light

Full sun / Part sun / Part shade

Water

Moderate water

Mature size

1-4 ft tall · 12" apart

Lifecycle

True annual (one season)

AHS heat range

1-11

Plant range authored in AHS heat-zone terms.

Native in Illinois

Yes

Related products

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

2050

2100

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 45 ecoregions - 45 climate-resilient through 2070. 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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California coastal sage and chaparral

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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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What it needs

Conditions

Light

Full sun / Part sun / Part shade

Water

Moderate water

Spacing

12"

Habit

Slender, erect, freely branching annual forb on smooth stiff stems, 2 to 4 feet tall and 12 to 18 inches wide by Missouri Botanical Garden, which is the figure for a well-fed garden plant. The Wildflower Center describes wild plants as 12 to 24 inches and sometimes taller, and records the species reaching about 5 feet at the extreme; Wikipedia gives 1 to 3.3 feet as the usual span. Read the difference as a plant whose size is set almost entirely by moisture and crowding rather than by genetics. Leaves are pinnately divided into narrow hairless segments, concentrated on the lower half of the stem, so the top of the plant reads as bare wiry stems carrying flowers - which is why it looks thin as a single specimen and solid as a drift. Flower heads are solitary on long stalks, 1 to 2 inches across, with 7 to 9 yellow rays marked maroon at the base around a red-brown disc. The fruit is a small flat winged achene.

Care tips

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Buy it as seed and sow it as a drift. This is an annual, so nothing you plant will be there in two years unless it sets seed first, and a single plant looks like a weed while fifty look like a meadow. Surface-sow onto firmed ground and press the seed in without covering it - it needs light to germinate. Autumn sowing works and needs no cold treatment.

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Starve it. Missouri Botanical Garden says it performs well in poor sandy or rocky soils, and the failure mode on rich ground is not disease but height: the stems lengthen, the plants lean, and MBG names staking in windy sites as the one problem worth mentioning. Do not improve the soil and do not feed it.

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Decide whether you are deadheading or seeding, because you cannot do both. Prompt deadheading prolongs bloom and prevents self-seeding; letting the heads stand feeds granivorous birds and produces the seed the next generation comes from. A common compromise is to deadhead the front of a planting through July and let the back go over.

Lifecycle

Planting

Missouri Botanical Garden calls it easily grown in dry to medium moisture, well-drained soil in full sun, tolerant of light shade, and says it performs well in poor sandy or rocky soils. Sow indoors 6 to 8 weeks before the last spring frost and set plants out after frost, or direct-sow after the frost date. The Wildflower Center prefers late autumn sowing for the following spring and specifies no cold treatment is needed. Seed germinates readily when exposed to light, so scatter it on a firmed surface and press it in rather than covering it. On rich soil the plant grows tall and floppy; poor ground gives a better plant, which is unusual enough to be worth stating twice.

Transplanting

Transplant only as a young hardened-off seedling, before it starts to branch. Like most fast annuals it moves badly once it is in bud, and direct sowing is both cheaper and more reliable for the drift-scale planting this species is actually for. Self-sown seedlings can be thinned in place far more easily than they can be shifted.

Early growth

Keep the seedbed evenly moist until seedlings are established, then ease off. Thin or sow thickly on purpose depending on the effect wanted: a dense stand supports itself and reads as a sheet of yellow, a thin one gives bigger individual plants that lean. Weed competition matters more at this stage than anything else, because a coreopsis rosette is small and slow next to a summer annual weed.

Maturity

Very little to do. Missouri Botanical Garden records no serious insect or disease problems and rates maintenance low; the only fault it names is that taller plants may need support in windy locations. Deadhead promptly if you want to prolong bloom and prevent unwanted self-seeding, and be aware those are the same operation - stop deadheading and the plant will sow the next generation for you. In a meadow that is the point; in a border it is the reason this species does not belong there.

Propagation

Seed, and only seed. There is no division and no cutting to take, which is the practical consequence of the annual habit and the sharpest difference from the perennial coreopsis in this group. Collect the achenes about four weeks after the flowers fade, per the Wildflower Center, and store them dry in a sealed container in the refrigerator. Seed comes true from an open-pollinated stand of the straight species, which is not the case for the named coreopsis cultivars most garden centres sell. Do not tip surplus seed into rough ground or a waterway: this species has naturalised across Europe, temperate and tropical Asia, the Pacific and the Caribbean, and its escape record is not theoretical.

Pollination

Needs cross-pollination

Insect-pollinated, and generalist about it. Wikipedia records the species as pollinated by a wide variety of insects including long-tongued bees, short-tongued bees, wasps, flies, butterflies and beetles, and the flower head explains why: a composite is dozens of small open disc florets presented on a flat landing platform, with the yellow rays and the maroon ring at their base acting as a target for anything that can walk. The Wildflower Center records nectar value for bees, butterflies and insects generally. What none of the sources cited here settles is self-compatibility, and this record will not guess - many Asteraceae are self-incompatible, but no source consulted makes that claim for Coreopsis tinctoria. In practice the question rarely arises, because this plant is sown as a drift rather than as a specimen and a drift is hundreds of unrelated individuals flowering together. The one case where it would matter is a single container plant kept for seed, and the honest answer there is that this record cannot promise it will set any.

Plants don't grow alone

Nectar forage

Bee

European honeybee (Apis mellifera)

The Wildflower Center records nectar value for bees on this species and Wikipedia names both long-tongued and short-tongued bees among its pollinators, but neither names the honey bee specifically, so this is marked plausible rather than documented. The flower suits it: a composite head is a dense mass of shallow florets that a medium-tongued generalist can work quickly, and the June to September bloom lands squarely in the colony-building season.

Nectar forage

Fly

Hover flies (flower flies) (Syrphidae)

Wikipedia names flies among the pollinators of this species. Hoverflies are the flies that matter on an open composite: they feed at shallow florets, they are abundant in disturbed grassland, and their larvae eat aphids, so a stand of coreopsis in a vegetable garden pays back twice. Marked plausible because the source names flies as a group and no hoverfly species is recorded on this plant.

Nectar forage

Butterfly

Skipper butterflies (Hesperiidae (family-level entry))

Both Missouri Botanical Garden and the Lady Bird Johnson Wildflower Center record butterfly value on this species, MBG under Attracts and the Wildflower Center as nectar for butterflies, neither naming species. Skippers are the butterflies most consistently found on short-tubed composite flowers in open grassland and they overlap completely with this bloom period, which is why they lead the butterfly entries here rather than a showier species.

Nectar forage

Butterfly

Pearl crescent (Phyciodes tharos)

A small aster-associated butterfly of open ground and roadsides, on the wing through the whole of this bloom season and a habitual visitor to low yellow composites. Listed as plausible on habitat and timing: the cited sources record butterfly nectar value at category level only. Note that the pearl crescent breeds on asters rather than on coreopsis, so this is a nectar relationship and not a host-plant one.

Pollen forage

Bee

Sweat bees (Lasioglossum spp.)

Wikipedia names short-tongued bees among the pollinators of this species without naming genera. Small sweat bees are the commonest short-tongued visitors to open composite flowers across North America, and a plains coreopsis stand is exactly the resource they exploit best - hundreds of shallow florets at a height a very small bee can reach. Recorded as plausible on flower architecture and abundance rather than a species-level observation.

Pollen forage

Bee

Long-horned bees (Melissodes spp.)

Melissodes and their relatives are the summer long-horned bees of North American grassland and a large share of them are Asteraceae specialists, active at exactly the midsummer window this plant occupies. Wikipedia names long-tongued bees among the pollinators, which is the group these belong to, but stops short of naming genera - hence plausible. If a meadow sowing of plains coreopsis is doing conservation work for any one group of bees, this is the likeliest candidate.

Seed forage

Bird

American goldfinch (Spinus tristis)

The Wildflower Center records seed value for granivorous birds and Missouri Botanical Garden lists birds under Attracts, neither naming a species. The goldfinch is the obvious candidate and the reason to leave part of a stand standing: it is a near-obligate seed eater of small composites, it breeds late specifically to match this seed crop, and it can work a coreopsis head while perched on the stem. Marked plausible because the sources stop at the category.

Seed forage

Bird

Pine siskin (Spinus pinus)

Listed on the same footing as the goldfinch and for the same reason - siskins are small finches that feed heavily on composite seed in autumn and winter flocks, and standing coreopsis stems hold their achenes above snow. Cutting a meadow to the ground in September removes this entirely, which is the practical point of recording it.

For people

Edibility undocumented

Genuinely unresolved, and worth stating rather than guessing at. None of the sources cited on this record assesses whether any part of plains coreopsis is safe to eat, and none lists it as toxic either. What is documented is human USE of two other kinds. Wikipedia records that the Zuni people used the blossoms to make a mahogany-red dye for yarn, which is where the epithet tinctoria comes from - it means used in dyeing. The same source records a historical hot beverage made from the plant before coffee arrived, and infusions of the plant excluding the roots used by Zuni women. A traditional preparation is not a safety clearance and this catalogue will not read it as one, particularly since flowers of this species are also sold commercially as a herbal tea under other names. Treat it as an ornamental and a wildlife plant until a source that actually evaluates edibility says otherwise. The dye use, by contrast, is a straightforward and pleasant thing to do with a stand of it.

Native range

Native

Naturalized

Native across 45 US states + 6 CA provinces; naturalized in 1 US state.

Worldwide native range.

AHS heat range

1-11

Native ecoregions

Naturally belongs in 41 ecoregions - its native range crosses a state or province each one spans (not necessarily this exact habitat).

Appalachian mixed mesophytic forests

›

Appalachian-Blue Ridge forests

›

Arizona Mountains forests

›

Atlantic coastal pine barrens

›

Blue Mountains forests

›

California coastal sage and chaparral

›

Canadian Aspen forests and parklands

›

Central Pacific Northwest coastal forests

›

Central Tallgrass prairie

›

Central-Southern Cascades Forests

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Climate notes

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The two range layers on this record disagree about what "native" means for this species, and the disagreement is the single most interesting thing about its distribution. Plants of the World Online, which answered directly for this taxon, maps it as native across essentially the whole of the United States and southern Canada plus north-eastern and Gulf Mexico - 55 botanical countries, from Alberta and British Columbia to Florida and Texas. Missouri Botanical Garden tells it differently: an annual native to the western United States, west of the Mississippi River, that has over time escaped from gardens and naturalised throughout most of the eastern United States to the Atlantic. The Wildflower Center agrees with MBG, summarising the native distribution as the plains of the central United States and naturalised elsewhere. Read the map here as the modern established range, not as a claim that this is an original prairie species in Connecticut or Rhode Island.

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Its actual home is the southern and central Great Plains, in prairie, plains, meadows, pastures, savannas, roadsides and pond banks, on moist sandy or clay soil from sea level to about 6,562 feet. Disturbed ground is its natural element: it colonises roadsides, ditches and field margins readily, which is both why it is in every wildflower mix and why it travels so well.

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Range provenance. The WGSRPD level-3 codes above came from Plants of the World Online, which returned this species directly rather than through the World Checklist fallback used elsewhere in this batch, and only native rows were kept. The 47 introduced territories POWO records are all excluded from the map. The per-state list carried alongside it comes from the Lady Bird Johnson Wildflower Center. The two do not match exactly: the Wildflower Center includes Hawaii, which POWO does not treat as native, while POWO includes New York, New Hampshire and north-eastern and Gulf Mexico, which the state list does not carry. The USDA PLANTS profile is cited for taxonomic resolution of the symbol COTI3 and was not readable in full at authoring time, so nothing in this record rests on it alone.

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Missouri Botanical Garden gives USDA Zone 2 to 11, which is a wider band than almost anything else in the catalogue and means less than usual here. Winter hardiness is close to irrelevant for a plant that is dead before winter arrives; the figure describes the range in which the annual cycle can be completed, not a plant surviving a cold season. What actually limits it is the length of the frost-free window and whether seed can ripen before it closes.

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The moisture picture is genuinely contradictory in the sources and should not be smoothed over. Missouri Botanical Garden grows it dry to medium, lists drought, dry soil, clay soil and shallow-rocky soil among its tolerances, and says it performs well in poor sandy or rocky soils. The Wildflower Center rates Water Use HIGH, prefers moist sandy soil, and comments that the species predominates in wet years. Wikipedia splits the difference: somewhat drought tolerant, but naturally found in areas with regular rainfall. The practical reading is that the plant survives dry ground and performs on moist ground, and that a wildflower sowing which looks spectacular one summer and thin the next is usually reporting rainfall rather than a mistake.

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Soil is otherwise not a constraint. It grows on sand, loam, clay and shallow rocky ground, and the Wildflower Center records a medium tolerance of calcium carbonate, so limey soil is no obstacle. Rich soil is the one thing to avoid, and not for health reasons: fed well, the stems lengthen and lean, and Missouri Botanical Garden names staking of taller plants in windy sites as the only real problem with the species.

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Deer are not a problem here. Missouri Botanical Garden lists deer among its tolerances and the Wildflower Center rates deer resistance HIGH, which is a meaningful advantage for an unfenced rural meadow sowing where most of the alternatives are browsed to the ground.

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It travels, and the record should say so plainly. Plants of the World Online lists this species as introduced in 47 territories outside its native range, including Great Britain, France, Germany, Italy, Spain, Portugal, Poland, Ukraine and the Baltic states in Europe; Kazakhstan, Uzbekistan, Turkmenistan, Pakistan, India, Myanmar, Vietnam, Korea, Japan and Taiwan in Asia; Java, Fiji and the Marianas in the Pacific; and Costa Rica, El Salvador, Trinidad and Tobago and Mozambique elsewhere. None of the sources cited here lists it as a noxious weed anywhere, so this is a widely escaped garden annual rather than a regulated invader - but it is a prolific self-seeder on disturbed ground, and gardeners outside North America should keep the seed on their own property.