Ornamental · Asteraceae
Coreopsis
Coreopsis grandiflora
Give it full sun and lean, dry soil and tickseed throws gold daisies from late spring to frost.
Full sun
Every 7–14 days
USDA 4–9
1–3 ft · 0.3–0.9 m
Overview
Coreopsis, which most folks call tickseed, is about as easy as perennials get for a sunny spot. It's in the daisy family, and it'll take a poor, dry, rocky corner and answer back with a long run of golden-yellow flowers that pollinators and butterflies work all season. And that funny name? It's got nothing to do with the bug; it comes from the little dry seeds, which look like ticks if you get up close.
The best part is how little this plant actually wants from you. It handles drought once it's settled in, takes lean, infertile ground without a fuss, and keeps blooming from late spring well into summer, often right up to the first frost. Rich soil and lots of water? That works against it, so the usual urge to baby a plant is exactly the wrong call here.
There are two camps worth knowing about. The large-flowered tickseeds carry big, bold daisies and bloom fast from seed, while the threadleaf types like Moonbeam and Zagreb swap size for a soft haze of fine foliage and smaller flowers that stick around longer. Either way, they want the same stuff: sun, sharp drainage, and a light hand.
Care
The short version: full sun and lean, well-drained soil, and only water once the top half has dried out. Go easy on the food, deadhead through the season, and shear the clump back in midsummer for a second flush.
Light
Coreopsis really wants full sun, and that's where it flowers best. It'll put up with a bit of afternoon shade, but much more than that and you're looking at floppy, leggy stems and way fewer blooms.
Water
Once it's settled in, this is a drought-tolerant plant, so let the top half of the soil dry out between drinks, roughly every 7 to 14 days. Honestly, sharp drainage matters more than any schedule. The quickest way to kill coreopsis is to keep it soggy.
Soil
Lean's the goal here. It does great in well-drained sandy, rocky, or clay ground, and it'll even shrug off poor, infertile spots, holding a slightly acidic to neutral pH of 5.5 to 7.0. Rich soil just makes it flop.
Humidity
Regular outdoor air is plenty, so there's no number you need to hit. What actually counts is drainage and airflow, because damp, crowded conditions are what invite rot.
Feeding
Feed it rarely, if you bother at all. A light touch during the growing season is plenty, since rich soil pushes soft, floppy growth instead of flowers.
Pruning
Snip off spent blooms through the season to keep more coming. Then shear the whole clump back in mid to late summer to kick off a fresh fall flush and tidy up any sprawling foliage.
Size & spacing
Plants run 1 to 3 feet (30 to 91 cm) tall and spread about the same. Give each one 1 to 3 feet (30 to 91 cm) of room so air can move freely through the clump.
When to plant
Coreopsis is a tough perennial that's happy in zones 4 through 9. Start seed indoors a few weeks before the last frost or just sow it straight in the ground, set plants out once spring's really settled, and the flowers show up from late spring into summer.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Sow: 6 to 8 weeks before last spring frost
- Plant: After last spring frost in spring
- Harvest: Late spring to late summer, sometimes to first frost
Hardiness
USDA hardiness zones: 4–9
Temperature: down to -34°C
Troubleshooting
Here's the thing: almost every coreopsis problem comes back to one culprit, too much water. Get the drainage right and most of the trouble below never even starts. When something does pop up, find what matches and deal with it before it spreads.
Mushy stems at the soil line and a plant that flops over
If the base of the stems has gone soft and the plant is keeling over, that's crown rot, and it's down to soggy soil, not a bug. Once the tissue at the bottom turns dark and mushy, the plant won't really come back, so just pull it and toss it. Want to avoid a repeat? Water less, sort out the drainage, and pop healthy divisions into ground that drains fast.
Fix:
- Remove and destroy affected plants
- Improve drainage and reduce watering
- Replant healthy divisions in well-drained soil
White fungal threads at the base with sudden collapse
Southern blight turns up in warm, sticky weather and can take a plant out in no time. The dead giveaway is a mat of white threads at the soil line, speckled with tan bits about the size of mustard seeds. So what do you do? Dig out the plant along with the soil around it, keep mulch away from the stems, and open things up so the air can move.
Fix:
- Remove and destroy infected plants and surrounding soil
- Avoid mulching directly against stems
- Improve air circulation and drainage
Ragged holes chewed in the leaves with slime trails
Those ragged holes are the handiwork of slugs and snails, which do most of their chewing at night when the ground's damp. See those silvery trails near the damage? That's how you know it's them. Head out after dark and pick them off, dry the bed out by easing up on water and mulch, and put traps or barriers around the plants they keep going after.
Fix:
- Hand-pick at night
- Reduce excess moisture and mulch
- Use traps or barriers
Few flowers on floppy, sprawling stems
Lots of leafy growth but barely any flowers? That usually comes down to soil that's too rich or too wet, and it gets worse if old blooms are left sitting on the plant. The fix is easy. Move it into full sun and lean, well-drained ground, go light on the food, snip off faded flowers as they appear, and shear the whole clump back in mid to late summer for a fresh round.
Fix:
- Deadhead regularly
- Shear back in mid to late summer
- Reduce fertilizer and grow in full sun and leaner soil
Toxicity
Good news if you've got animals at home. Coreopsis is non-toxic to cats, dogs, and horses on the ASPCA's list, and it's no known threat to other animals or people either. So a nibbled leaf or flower? Really nothing to stress about.
Safe for
People · Cats · Dogs · Horses · Rabbits · Livestock · Birds
Cats None
Cats are totally fine around it. The ASPCA has coreopsis down as non-toxic, so if yours sneaks a bite, there's nothing to worry about.
Dogs None
Dogs are good here too. There aren't any known toxins in it, though if a dog scarfs down a big pile of any plant, it might get a quick, harmless upset stomach.
Horses None
Horses are covered as well. It's listed as non-toxic, so there's no poisoning risk where they're grazing.
Rabbits Safe
Rabbits are fine with it. If one decides to munch the leaves or flowers, there's nothing in there that'll do any harm.
Livestock Safe
Cattle, goats, and sheep can graze right next to it, no toxicity worries at all.
Birds Safe
It's harmless to birds, and a lot of them actually go looking for the dried seed heads to snack on.
People Safe
No toxicity to people either. It's grown as a garden flower, not something to eat, so there's no part you'd harvest for the table.
Varieties
There are dozens of named coreopsis selections out there, but a handful keep showing up for good reason. These are the ones worth knowing by name.
Coreopsis verticillata 'Moonbeam'
It's a threadleaf type with feathery, finely cut leaves and soft pale yellow flowers that hang around for a long season.
Coreopsis verticillata 'Zagreb'
A compact threadleaf pick that keeps a neat, mounded shape under cheerful golden-yellow flowers.
Coreopsis verticillata 'Grandiflora'
A more compact threadleaf form that tops out around 2.5 feet, with bright golden-yellow daisies up top.
Coreopsis grandiflora 'Early Sunrise'
A large-flowered tickseed with semi-double golden blooms that's quick off the mark, flowering from seed in its first year.
How to propagate
Making more coreopsis is easy, whether you split a clump you've already got or start it from seed, and a lot of the time it'll reseed itself before you even get around to it.
DivisionEasy
Early spring; divide clumps every 2 to 3 years to maintain vigor · One growing season
Dividing is hands down the best way to keep coreopsis going strong. In early spring, dig up an established clump, split it into healthy chunks, and replant them to perk up tired plants and stop the spread from getting away from you. Give it a single growing season and the divisions will be settled in.
SeedEasy
Start indoors 6 to 8 weeks before last frost or direct sow; self-seeds readily · Blooms first year for many large-flowered types
Coreopsis is a breeze to grow from seed, whether you start it inside 6 to 8 weeks before the last frost or just sow it straight into the bed. A lot of the large-flowered types will flower their first year. Large-flowered tickseed can be short-lived, sure, but it reseeds itself so freely that the patch basically keeps itself going.
Myths
Tickseed got its name because the plant pulls in ticks or gives them somewhere to live.
Nope, the name's about the seeds, not the bugs. Each little dry seed just happens to look like a tick, and honestly that's the whole story. What it really draws in is pollinators and butterflies, not ticks.
Coreopsis is poisonous, so it's best kept away from cats and dogs.
Not the case, actually. The ASPCA lists coreopsis as non-toxic to dogs, cats, and horses. So if a pet nibbles a leaf or flower, it's in no danger at all.