Large Flowered Tickseed – A Complete Guide To Grow & Care

Large Flowered Tickseed is a showy, short-lived perennial native to central and eastern North America. Scientifically known as Coreopsis grandiflora, it grows 1-3′ tall in full sun and well drained soil. Blooming a profuse number of yellow flowers in Summer for 2-3 months, it attracts a variety of bees and butterflies.[1][2][3]

In this article:

What is Large Flowered Tickseed

A somewhat common landscaping flower, Large Flowered Tickseed really is a showy flower that puts on a show that lasts longer than most species. This combined with it’s somewhat compact nature make it a great choice for formal flowerbeds as well as short meadows, borders, or along sidewalks and streets.

Large Flowered Tickseed is one of those flowers that keeps putting out blooms well into late Summer. This feature helps you keep something blooming all season long [4], which means you can feed the bees all season long.

To keep it looking it’s best you should consider deadheading it every day or two, as toward the end of the season the seed heads can be considered unattractive (although they will feed the birds). We have an article that discusses pros and cons of deadheading and provides a nuanced perspective on whether or not you should deadhead flowers.

I am not deadheading mine, as the above image plainly shows!

However the extreme number of flowerheads can also be a curse, as it can sometimes mean the plant won’t return the following year. But cutting it back to it’s basal leaves in late August can often stimulate new leaves, resulting in the plant returning the following Spring.[5]

One thing to note, the large number of flowerheads will also mean large numbers of seed heads, and in-turn seeds. Birds will eat these and likely spread the plant around your gardens. It isn’t too hard to manage in formal mulched flowerbeds, as you can simply rake the young seedlings or transplant them to new areas. But be aware that Large Flowered Tickseed will self-seed.

Native Range of Large Flowered Tickseed

The native range of Large Flowered Tickseed (Coreopsis grandiflora) is primarily in the Southern and Central United States. From Texas to Florida, north to Kansas and North Carolina. Also, within it’s native range there are several naturally occuring varieties recognized.[6]

Click on image to enlarge. Source [1]

Large Flowered Tickseed spread beyond it’s native range

Due to it’s adaptability and frequent use as an ornamental flower, Large Flowered Tickseed has escaped it’s native range and become established in a number of states in North America . It has established populations in Iowa/Wisconsin up to Southern Ontario Canada and New England.

Furthermore it’s use as an ornamental has made it a noxious weed in various parts of the world. It has been declared invasive in Australia, China, and parts of Europe.[7][8][9]

Large Flowered Tickseed Reference Table

Scientific NameCoreopsis grandiflora
Common Name(s)Large-flowered Tickseed, Largeflower Tickseed, Tickseed, Common Coreopsis
Native Range, USDA ZoneUSDA Hardiness zones 4-9, Southern United States
Bloom TimeSummer
Bloom Duration, ColorTwo months, Yellow
Spacing / Spread12″
Light RequirementsFull sun
Soil TypesSandy-loam to clay-loam, well-drained
MoistureDry to medium
Fauna Associations / Larval HostsBees, butterflies
Sources [1][2][3][4]

What are the Benefits of Large Flowered Tickseed


Large Flowered Tickseed is a very showy species of Coreopsis. Putting out near continuous blooms for two months that are eye-catching and pleasing, this flower can add curb appeal to your home.

Drought tolerant

Large Flowered Tickseed is one of those flowers that thrives in shallow, well-drained soil in the sun. Easily grown in rock gardens or light soil, it would make a great choice for a hellstrip or other areas that are inhospitable to many other species of plants.


Typically growing 12-30″ tall, this is a landscape flower that won’t be overbearing to other species. Even when it gets tall it may flop over, but here’s the thing – it still looks good if it is sprawling/flopping. The stems orient themselves upward and still manage to look good!

Identification and Characteristics of Large Flowered Tickseed


The stem of Large Flower Tickseed is smooth, green, and round. Multiple stems will emerge from the root crown, and these will branch as well.


The base of Coreopsis Grandiflora will have simple basal leaves that are lanceolate to ovate in shape with smooth margins, and are roughly 3-4″ long by 1-2″ wide.[2][3]

Upper leaves are opposite along the stalk are pinnately or pedately lobed with typically 3-5 lobes. The shape of the lobes are narrowly lanceolate to linear in shape, and 1/2″ -2″ long by roughly 1/4″ wide.[2][3]


Flowerheads form on long stems and are overall roughly 1-3″ diameter with 6-15 yellow ray florets surrounding a group of disk florets. The of the petal will have several notches.[2][3]

Blooming begins in late Spring and continues until late Summer, lasting 2-3 months depending on how much you deadhead it.

How to save seed

Several weeks after a bloom fades the flowerhead will turn brown and dry. Collect flowerheads at this time, and crush them over a plate. The seeds will fall out and have a shape that is somewhat similar to ticks, hence the name, tickseed.

I simply crushed one of the many brown, dry seedheads. The seeds are small ‘flake-like’ seeds .

Dried seed can be stored in an envelope or zip-lock bag for several years in a cool, dry place.


The root system of Large Flower Tickseed are fibrous and spreading. Interestingly, the root system has been found to emit allelopathic chemicals which can inhibit the growth of other species – this effect has been noted in China.[10]

Root system of Coreopsis grandiflora

Grow and Care for Large Flowered Tickseed

Sunlight Requirements

Large Flowered Tickseed should be grown in full sun, which is at least six hours of direct sunlight per day. It will not be nearly as showy in partial shade.[3]

Soil Requirements

For soil texture, Large Flowered Tickseed isn’t too picky as long as it drains well. This plant does not like wet feet, so check your soil drainage before planting, or try to plant in a mound. [3][4]

Moisture Requirements

For moisture, Large Flowered Tickseed prefers dry to medium moisture and is fairly drought tolerant.


If you are trying to keep this plant looking it’s best, then deadheading spent flowers (almost daily) is a necessary chore. Also, cutting down all of the foliage to the basal leaves in late August will help increase the chances of this plant coming back the following year. [5]


Since Large Flowered Tickseed self-seeds, you should plan on removing new unwanted seedlings in the Spring. Large Flowered Tickseed can be cut to ground in late August, and this will increase the chances of it returning in the Spring. [5]

These are some volunteer seedlings in my flowerbed


Large Flowered Tickseed will not require any supplemental fertilizer. Fertile soil or applying fertilizer will likely cause it to flop over. [3]

How to Grow Large Flowered Tickseed from Seed

Large Flowered Tickseed is relatively easy to grow from seed but does have two dormancy mechanisms that need to be overcome. The first is that the seed must be surface sown, as it needs exposure to sunlight to germinate. The second is that germination rates will improve if it undergoes a 30 day cold moist stratification period.[11] This is most easily overcome via Winter Sowing, but the stratification can be done in the fridge as well.

One nice feature of growing Large Flowered Tickseed from seed is that it will often bloom the first year. But the plant needs exposure to cold weather to flower.[12] So, if you are germinating the flowers in Spring when nighttime temperatures get down to the 40’s or just Winter Sowing, then you will cover this requirement. But if the seed is germinated in June or later, it likely won’t flower until the second year.

Process to germinate Large Flowered Tickseed

The following steps assume you either have stratified the seeds in the refrigerator for 30 days, or are Winter Sowing.

  1. Fill a suitable container with moist potting soil. The soil should be moist enough where if you squeeze a handful several droplets fall out.
  2. Press 3-5 Large Flowered Tickseed seeds into the soil, ensuring good contact.
  3. Water by misting with a spray bottle so that the seed doesn’t get covered.
  4. Germination should occur within 2 weeks once temperatures warm up.

Direct sowing Large Flowered Tickseed

You can direct sow Large Flowered Tickseed in very late Winter or early Spring. Simply scatter the seed on disturbed soil and walk over it to ensure it has good contact. You can also direct sow in Autumn or Winter, but know that both birds and rodents love to eat the seed, and many will likely be consumed.

Wildlife, Pests, and Diseases associated with Large Flowered Tickseed


Large Flowered Tickseed attracts various bees, butterflies, and skippers. It will primarily attract smaller bees, such as sweat bees, which are not as noticeable. [3]


Large Flowered Tickseed is deer and rabbit resistant. I have almost never seen damage to any of my plants. Also, mice and other rodents do enjoy eating the seeds when they fall from the seedheads.


Birds love to eat the seed of Large Flowered Tickseed. This is a strong argument for not deadheading the flowers, as it will feed the birds.


Large Flowered Tickseed is susceptible to rust, leaf spot, powdery mildew, and downy mildew. These diseases are a sign of stress on the plant, likely from too much or too little water. But the effects are only cosmetic, not fatal.[3][13]

Where you can buy Large Flowered Tickseed

Large Flowered Tickseed is often available at garden centers, although these will likely be cultivars, which may not be as attractive to pollinators. The straight native species can be purchased at specialty nurseries that deal in Native Plants. You can find native plant nurseries near you on our interactive map.

Varieties of Large Flowered Tickseed

There are numerous cultivars and varieties of Large Flowered Tickseed that have been developed by the landscaping and nursery industry over the years.[14][15] Most of these are bred for their compact size, more attractive foliage, or disease resistance. Some examples are the following:

  • Coreopsis grandiflora ‘Early Sunrise’
  • Coreopsis grandiflora ‘Sunburst’
  • Coreopsis grandiflora ‘Sunray’
  • Coreopsis grandiflora ‘Goblin’

Where to buy seeds

We have ordered a variety of native flower seeds from Everwilde Farms, which you can order right from Amazon through our link on our RECOMMENDED PRODUCTS PAGE. (We may earn a small commission when you purchase through our links, at no cost to you. This helps support our website.)

Uses of Large Flowered Tickseed

Garden Uses

Large Flowered Tickseed can make for a very nice addition to a formal flowerbed, a short border, or planted along the street/sidewalk. It is rather adaptable and although it is often short-lived, it’s life can be prolonged by pruning in August. Or you can just let it self-seed a bit, as it will flower the first year anyway!

Just remember, if you grow it in fertile soil…it will flop over. But I must say, when it comes to plants that flop, Large Flowered Tickseed looks better than just about anything else laying down. It almost resembles a groundcover when it falls over.

This plant has completely flopped over. But in truth it looks like a ground-cover!

Companion Plants

There are numerous companion plants that look good and can grow in similar conditions as Large Flowered Tickseed. Some of those are as follows:

Medicinal Uses

I could not locate any medicinal use, nor Native American use of Large Flowered Tickseed.

Final Thoughts

Large Flowered Tickseed is probably one of the easiest flowers for new gardeners to grow. It is relatively easy to start from seed, and can be a confidence builder for a newbie, and they will also be rewarded in the first year when it blooms. It’s adaptability and versatility also make it a great choice, to say nothing of providing a nectar source for pollinators.

Find more native plants here


[1] – Coreopsis Grandiflora. USDA NRCS. Accessed 02SEP2023.

[2] – Coreopsis grandilora. Flora of North America, FNA Vol.21 Accessed 02SEP2023.

[3] – Kahtz, Anthony W, Perennials for midwestern gardens : proven plants for the Heartland, Portland, Or. : Timber Press, 2008, pp231.

[4] – Duthie, Pam, Continuous Bloom, Ball Publishing, 2000, pp346

[5] – DiSabato-Aust, Tracy, The well-tended perennial garden : planting & pruning techniques, Portland, Or. : Timber Press, 2006, pp387

[6] – Coreopsis Grandiflora varieties. USDA NRCS. Accessed 02SEP2023

[7] – Peng, Ye, et al. “Prediction of potential geographic distribution of alien species Coreopsis grandiflora in China.” Journal of Nanjing Forestry University 59.01 (2016): 53.

[8] -Batianoff, George N., and David A. Halford. “Coreopsis lanceolata L.(Asteraceae): another environmental weed for Queensland and Australia.” Plant Protection Quarterly 17.4 (2002): 168-169.

[9] – Marazzi, Brigitte, et al. “Biology and spread of the new alien species Coreopsis grandiflora (Asteraceae) in southern Switzerland.

[10] – Gao, Yan, et al. “Allelopathic effects from aqueous extracts of exotic Coreopsis grandiflora on seed germination of six native ornamental plant species.” Journal of Zhejiang Forestry College 28.1 (2011): 109-114.

[11] – Norcini, Jeffrey G., and James H. Aldrich. “Liner Production of Florida Native Wildflowers by Seed: ENH1087/EP342, 12/2007.” EDIS 2008.2 (2008).

[12] – GrowerTalks on perennials. Ball Publishing. 2002. pp324

[13] – Skrzypczak, C. “Occurrence of downy mildews on ornamental plants and their control by chemical compounds.” Communications in Agricultural and Applied Biological Sciences 72.4 (2007): 801-804.

[14] – Yuan, Mei, et al. “Effect of Temperature on Time to Flower of Coreopsis grandiflora, Chrysanthemum superbum, Gaillardia grandiflora, and Rudbeckia fulgida.” HortScience 30.4 (1995): 861B-861.

[15] – Hoover, Benjamin K. “Herbaceous perennial seed germination and seedling growth in biochar-amended propagation substrates.” HortScience 53.2 (2018): 236-241.

Joe Foster

Hi - I grew up outdoors in nature - hiking, fishing, hunting. In high school I got my first job at a garden center where I learned to garden and landscape. I've been growing plants from seed and designing native plant gardens for over 10 years. I hope to share some of my knowledge with you! You may have seen some of my videos I create on our YouTube channel, GrowitBuildit (more than 10 million views!). You can find my channel here: Additionally I am a wood worker / DIY enthusiast. I enjoy designing/building projects (with hand tools when I can!). I hope to give you some tips and useful information!

Recent Posts