Tall coreopsis
Coreopsis tripteris · Asteraceae
A tall, airy prairie plant: small, pale yellow daisies with brown centres on wiry stems above head height in late summer.
- Size
- 6 ft tall, 3 ft wide
- Zones
- 3 to 8
- Light
- Full sun
- Flowers
- Early August to mid September
- Pets
- No toxicity recorded
- Job in a bed
- Accent
A bed built around tall coreopsis
The planner designed this bed around tall coreopsis when this page was made: a 12 × 6 ft (3.7 × 1.8 m) naturalistic planting in zone 6, full sun. It chose the other plants from the 966 that suit those conditions, and says below why tall coreopsis stands where it does.
The plants
- 1 Tall coreopsis × 1, yellow
- 2 Mountain avens × 8, white
- 3 Creeping phlox 'Emerald Blue' × 5, blue
- 4 False sunflower 'Summer Nights' × 3, yellow
- 5 Little bluestem × 3, blue-green leaves
- 6 Ornamental onion 'Purple Sensation' × 5, purple
- 7 Daffodil 'Tete-a-Tete' × 12, yellow
Why this plant
- Nothing here is unique to it. Its leaf, flower shape and colour are all on the plan already. Its case rests on where it stands and when it performs.
Why here
- Anchors a back corner. At 6 ft it is the tallest plant here, and the tallest close the ends of the bed, where they stand in front of nothing.
- A step in the back row. Next to little bluestem (3 ft): no two neighbours there are the same height, so the back steps up and down like a skyline.
- One plant, alone. A feature plant is seen as an object, and needs clear ground around it.
Why now
- In flower for 8 weeks. From early August to mid September.
- Closes the season. For its last two weeks nothing else on the plan is in flower.
Planned as a naturalistic planting: low grasses and groundcovers, the matrix, make up 69% of the planted ground. Three kinds, among them mountain avens and creeping phlox 'Emerald Blue', carry the bed through winter. The scheme leans hot (yellow) and uses blue and purple for relief, with white to calm things between them.
The planner's own design check: 9 Excellent, 7 Good, 1 Satisfactory. It flags one thing to watch: Nothing on this plan is highly poisonous or an aggressive spreader.
Open this bed in the planner Change its size, the sun or the style, move plants about, or swap one for another.
Where tall coreopsis goes in a border
At 6 ft it belongs at the back of a bed. In the planner's ten height classes it is very tall (5 to 6½ ft). It is airy enough to see through, so it can also come forward and veil what is behind it.
Its job: accent. An upright plant used singly, like a punctuation mark, and repeated at intervals to give the bed rhythm.
Despite its height it is light enough to look through, and the stems stand without staking. It belongs at the back of a big bed among grasses and Joe Pye weed, not in a small border.
- Height for large naturalistic plantings
- A see-through screen
- Late nectar for pollinators
What to plant with tall coreopsis
Plants recorded as good partners for it, and what each pairing does:
- Joe Pye weed 'Gateway': in flower together for seven weeks, from early August; bold leaves against its medium ones.
- Switchgrass 'Shenandoah': its green leaves are a setting for the flowers, before and after.
- New England aster: purple against yellow, opposite each other on the colour wheel, if you choose those colours, in flower together for three weeks.
Questions about tall coreopsis
Does tall coreopsis need sun or shade?
Tall coreopsis grows in full sun (6 or more hours of direct sun a day).
It wants ordinary well-drained soil, of average fertility, and a good soak in dry spells. Once settled in, it stands drought.
What zones does tall coreopsis grow in?
USDA zones 3 to 8. It is hardy to zone 3, which means it survives winter nights down to about −30 °F (−34 °C).
Above zone 8 it struggles: the zones measure winter cold, but a plant's top zone usually means the summers are too hot or the winters too mild for it to rest.
Gardening in Canada? Use the USDA zone for your town: Canada's own zone map uses different numbers.
When does tall coreopsis flower in my zone?
In zone 5 it flowers early August to mid September. As a summer flower it moves about half a week for every zone: earlier where it is warmer.
| Zone 3 | Early August to mid September |
|---|---|
| Zone 4 | Early August to mid September |
| Zone 5 | Early August to mid September |
| Zone 6 | Early August to mid September |
| Zone 7 | Late July to mid September |
| Zone 8 | Late July to mid September |
Worked out from Hopkins' bioclimatic law: spring arrives about four days later for each degree of latitude north, and one zone is roughly two degrees. A warm spring or a cold one moves any garden two weeks either way.
How far apart should tall coreopsis be planted?
2½ ft (75 cm) apart, from the middle of one plant to the middle of the next. That is a little closer than its full width of 3 ft (90 cm), so a group knits into one patch.
It grows 6 ft (180 cm) tall. Give it the full distance from anything taller, or it will lean out towards the light.
How many tall coreopsis plants do I need?
At 2½ ft apart, set out in staggered rows:
- 2 to fill 10 square feet (about 1 m²)
- 5 for a single row 10 ft (3 m) long
- 6 to fill a 4 × 8 ft bed on its own
In a mixed border, plant it as one at a time, repeated along the bed at intervals; a slender one reads better as a clump of three.
In the bed above, the planner used one in one group.
Is tall coreopsis poisonous to dogs and cats?
No toxicity is recorded for dogs, cats, horses or people, according to NC State Extension and the ASPCA.
"Not toxic" is not "edible": a pet that eats a lot of any plant can be sick.
Do deer eat tall coreopsis?
Mostly not. NC State lists it as resistant to deer. No plant is proof against a hungry deer in a hard winter, but this one is low on the menu.
Will tall coreopsis spread?
It spreads sideways, by runners or roots; the risk of it taking over is moderate. Spreads by underground runners and can crowd its neighbours. Dig out the edges or divide every 2 to 3 years.
What flowers after tall coreopsis?
Tall coreopsis is over by mid September. These start as it finishes and carry the same spot on, so it never goes flat:
- Garden chrysanthemum: from mid September to late October, 24 in tall, to stand in front of it and cover its fading stems.
- Montauk daisy: from mid September to late October, 3 ft tall, to stand in front of it and cover its fading stems.
- Tatarian aster 'Jindai': from early October to early November, 4 ft tall, to stand in front of it and cover its fading stems.
What does tall coreopsis look like in winter?
Tall coreopsis dies down, but leave the stems standing: the seed heads stand through the winter, and songbirds eat the seed. Cut them down in early spring, before the new shoots come.
Is tall coreopsis good for bees and butterflies?
Tall coreopsis is visited by pollinators and songbirds.
It is native to the United States and Canada.
More Coreopsis
- Coreopsis 'Full Moon' Coreopsis 'Full Moon'
- Coreopsis 'Jethro Tull' Coreopsis 'Jethro Tull'
- Coreopsis 'Mercury Rising' Coreopsis 'Mercury Rising'
- Lanceleaf coreopsis Coreopsis lanceolata
- Mouse-ear coreopsis 'Nana' Coreopsis auriculata 'Nana'
- Pink tickseed Coreopsis rosea
- Prairie coreopsis Coreopsis palmata
- Threadleaf coreopsis 'Moonbeam' Coreopsis verticillata 'Moonbeam'
- Threadleaf coreopsis 'Zagreb' Coreopsis verticillata 'Zagreb'
- Tickseed 'Early Sunrise' Coreopsis grandiflora 'Early Sunrise'
- Tickseed 'Sunray' Coreopsis grandiflora 'Sunray'
In these guides
- Deer-resistant perennials for full sun
- Drought-tolerant perennials for full sun
- Pet-safe plants for a sunny border
- Native perennials for pollinators
- Garden plants native to Canada
- Plants that feed garden birds
- Tall perennials and grasses for the back of a border
Zone guides: Zone 3 · Zone 4 · Zone 5 · Zone 6 · Zone 7 · Zone 8
Every fact on record
- Type
- Perennial
- Size
- 6 ft (180 cm) tall, 3 ft (90 cm) wide
- Plant
- 2½ ft (75 cm) apart
- Height class
- Very tall (5 to 6½ ft)
- Place in the bed
- Back, or further forward: it is airy enough to see through
- Flowers
- Early August to mid September; daisies; yellow
- Leaves
- Medium texture, herbaceous; green
- Shape
- Upright, spreading
- Hardy in
- USDA zones 3 to 8
- Light
- Full sun
- Soil
- Average, well-drained
- Water
- Moderate
- Feeding
- None needed
- Family
- Asteraceae
- Comes from
- Eastern Canada to the Central and Southeastern United States
- Attracts
- Pollinators, songbirds
- Stands up to
- Deer, drought, heat, poor soil
Checked against NC State Extension, ASPCA poison lists and VASCAN (plants of Canada). Flowering times are for zone 5: later in colder zones, earlier in warmer ones. Toxicity and spread information is a general gardening guide, not veterinary or medical advice, and invasive status varies by region. If a person or pet eats a plant, contact poison control or a vet. Check your local invasive species list before planting anything with a spread warning.