Tall Coreopsis – Complete Guide To Coreopsis tripteris

What are the Benefits of Tall Coreopsis

Beauty

The flowers of Tall Coreopsis make for a stately and elegant appearance, towering over most other plants. They make a hypnoitic and zen-like experience when swaying in the breeze on a windy day, glowing their bright yellow blooms (especially when contrasted against a dark forest background).

Long bloom time

Tall Coreopsis typically blooms six weeks, but has been recorded up to 8 weeks.[2] This is primarily because the blooms open and close over time, rather than all at once.

Foliage

The dark green foliage of Tall Coreopsis is attractive year round, looking ornate and elegant. It’s leaves rarely have damage on them, and looks great pretty much all the time.

Wildlife

Tall Coreopsis brings in a large variety of pollinators and birds who eat the seeds. Particularly bees, but also butterflies are attracted to the central disc for pollen and nectar.

Identification and Characteristics of Tall Coreopsis

Stalk

Tall Coreopsis can grow up to 8′ tall in optimum conditions. It will branch in the upper half where flowers occur. The stem is round green to blue-green and smooth, and sometimes has a waxy coating.

Leaf

Leaves of tall Coreopsis are opposite, odd-pinnate with 3 to 5 leaflets. Individual leaflets are up to 5″ long by 1/2-1″ wide, linear to elliptic in shape with smooth margins (edges).

Flower

Flowerheads occur in opposite-branching clusters (corymbs) that can be 8″ long. Individual flowers are 1-2″ diameter with 8 petals and a dark brown/black center. Blooming lasts for approximately four weeks in mid-Summer for an individual plant, but bloom time can vary based on sunlight conditions (shaded plants bloom a week or two later).

How to save seed

About 4-6 weeks after blooming seed heads will form. Cut the stalk below the flowering heads below and place in a paper bag or container. Leave it to dry for another week in a cool dry a place such as a garage.

Place seed heads into plastic container with lid, and shake the seed heads violently. This will release the seed and some chaff. Separate chaff using a kitchen strainer over a plate.

Fully dried seed of Tall Coreopsis can be saved for 2-3 years in a zip-lock bag or envelop in a cool-dry location.

Root

The root system of Tall Coreopsis is fibrous and rhizomatous. The rhizomes are far ranging, not clump forming. So this flower will spread over distances, similar to Canadian Goldenrod.

In my backyard micro-prairie I have numerous plants, all rhizome-volunteers from the original few I planted 5-6 years ago. Unwanted plants can be pulled.

Grow and Care for Tall Coreopsis

Sunlight Requirements

For sunlight, Tall Coreopsis will prefer full sun, which is six hours of direct sunlight per day. It can tolerate partial shade, which is 4-6 hours per day but it will not grow as tall nor be as showy.

Soil Requirements

Tall Coreopsis can grow in a wide variety of soil textures, from sandy moist soil to clay.

Moisture Requirements

For moisture, Tall Coreopsis prefers moist to medium-moist soil. It can withstand drought once fully established (3 years from seed in my experience).

Maintenance

Since Tall Coreopsis spreads via rhizomes, you may need to pull unwanted plants in the Spring depending on where you’ve located the plants.

While many species of tall flowers have reputations for leaning or flopping, I haven’t seen that with any of specimen of Tall Coreopsis when grown in my backyard micro-prairie. This plant seems to stand tall and not really lean at all despite whatever light conditions you provide it. However in mulched gardens, without competition, it has been known to flop.[2][3]

However, if you would prefer your Tall Coreopsis to not be so tall…then you can perform the Chelsea Chop on it in early June.

Fertilizer

Tall Coreopsis will not require any fertilizer or any kind. Nitrogen fertilizers could make it more top-heavy and thus more prone to flopping.

How to Grow Tall Coreopsis from Seed

References are mixed on whether Tall Coreopsis requires special treatment to break seed dormancy. However, research has noted that seed emergence is higher when planting in Winter, indicating that a cold-moist stratification period will benefit germination rates.[5]

Cold stratifying for sixty days in the refrigerator or Winter Sowing should provide significant improvements to the germination rate. I can personally attest that Winter Sowing Tall Coreopsis to be an effective method for germinating the seeds in Spring.

Steps to germinate Tall Coreopsis seed

The following process assumes you have either cold-stratified the seed in the fridge for about two months, or are winter sowing.

1. Fill a container with moist potting soil.
2. Plant Tall Coreopsis seed 1/16-1/8″ deep (1.5-3 mm) and cover
3. Water container
4. Place container in a location that receives morning sun and afternoon shade
5. Germination will occur in Spring as temperatures warm up

Wildlife, Pests, and Diseases associated with Tall Coreopsis

Pollinators

Tall Coreopsis attracts a large number and wide variety of pollinators. Charles Robertson observed no less than 53 species visiting the flowers in his exhaustive 1929 survey. This includes 18 species of Long-tongued bees, a dozen species of short-tongued bees, and a variety of butterflies. [4][6]

There are some insects that will feed on foliage and flowerheads of Tall Coreopsis.[7] But the damage is cosmetic only, and doesn’t significantly effect the appearance unless one gives a close inspection.

Birds

Goldfinches and other song birds love to eat the seeds from Tall Coreopsis. It is quite entertaining to see the tall plant swaying or bending under the weight of a bird visiting to eat some seed.

Deer and Rabbits

Deer and rabbits will feed on this plant in Spring when the foliage is young and tender. It has happened to me multiple years. I recommend using Liquid Fence to dissuade them.

Disease

Tall Coreopsis is generally not bothered by any disease.

Where you can buy Tall Coreopsis

Tall Coreopsis is not typically sold in nurseries, as it’s height and rhizomatous nature aren’t always considered ‘garden friendly’. But it 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 Tall Coreopsis

The Mount Cuba Center has identified and noted cultivars varieties of Tall Coreopsis. [8] These breeds are a bit shorter with stems that are more stout. This feature is to help reduce the chances of it flopping or leaning in formal, mulched flower beds.

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 Tall Coreopsis

Garden Uses

It is best to use Tall Coreopsis in a meadow, microprairie, or wildflower garden. It can do well in a formal flowerbed that is densely planted though, as the competition will help limit it’s rhizome volunteers.

Tall Coreopsis can be used in a formal flowerbed if steps are taken to limit it’s spread. Even still though, you will likely have to remove some unwanted plants each year. Planting it in a pot with the bottom cut out can slow rhizome production while still allowing plenty of moisture to the roots.

Companion Plants

For companion plants of Tall Coreopsis, choose those that like full sun and moist to medium-moist soil.

Below are some plants that like similar growing conditions but are shorter, and would do well to the South or in front of Tall Coreopsis:

• Bee Balm (Monarda didyma)
• Blue Vervain
• False Sunflower
• Halberd Leaf Rose Mallow (Hibiscus laevis)
• Ironweed
• Purple Coneflower
• Purple Giant Hyssop
• Purple Joe Pye Weed
• Showy Goldenrod
• Sneezeweed
• Swamp Milkweed
• White Turtlehead

Some plants that will grow well near Tall Coreopsis and rival it’s height include the following:

• Hollow Joe Pye Weed
• Maximilian Sunflower
• New York Ironweed
• Sawtooth Sunflower
• Tall Sunflower
• Wild Sunflower

Native American Uses

The Meskwaki Tribe used Tall Coreopsis a couple of ways. A decoction of stems could be used to treat either internal pains or for internal bleeding. [9]

Final Thoughts

Tall Coreopsis is a beautiful, stately wildflower that can find a home in most gardens. It’s foliage looks great all season, and the wildlife it attracts make it worth the effort. These benefits balance it against any unwanted seedlings you may need to pull throughout the year, although taking some steps to limit it’s spread could help reduce the rhizomes volunteers significantly.

Find more native plants here