Zone: 4 to 9
Soil: Sand to loam
Light: Full sun to part sun
Bloom colour: Yellow and pink
Bloom period: The whole summer
Height: Usually 15 inches but up to 10 ft.
Moisture: Dry to medium
Attracts: A variety of small bees, bumblebees and syrphid flies. It also attracts butterflies.
Notes: Coreopsis mostly produce yellow flowers that are attractive to bees. They are quite common in gardens where there is sandy soil and they resist drought well.
Threadleaf Coreopsis is a low maintenance plant that flowers all summer if deadheaded. It grows to about 15 inches high and forms a spreading clump that will eventually fill in the space that has been allocated to it. It is commonly available in many nurseries but this species of Coreopsis is introduced into Canada.
Coreopsis lanceolata, a native of Ontario, is one of those plants that has a happy-go-lucky look to it. It has large flowerheads and is appealing when mixed with other plants. To get the most flowers in a season, it is best practice to deadhead the blooms on a regular basis. This plant will start blooming in June and will flower till the end of August. Without deadheading, flowering will be sporadic. The flower reproduces quite easily by self-seeding, but not to the extent that it becomes problematic. It grows 2-3 feet in height so you can find a spot for this plant in any garden. It does well in dry sandy soil.
Tall coreopsis (Coreopsis tripteris) grows over 8 ft. high and is for larger beds. With its thick spray of flowers and its bamboo-like leaves, it can provide a fabulous backdrop to show off other perennials in August and September. It is far more impressive when planted in groups and it is the best species of Coreopsis to attract wildlife. It draws both butterflies and a wide variety of bees. The hollow stems can also be used to make bee houses. In part sun, it will definitely need support, which may be aided byplacing other quite tall plants in front of it. Choose a companion plant that flowers at the same time for best effect. In the photograph shown here, it has been planted behind Joe-Pye Weed. Great Blue Lobelia and a white Phlox would also be a great choice. Tall coreopsis does need more water than C. lanceolata. A mesic soil is best.
Coreopsis lanceolata and C. tripteris are both native to Ontario. The former is a plant suitable for the middle of the border in regions with dry sandy soil while the latter prefers mesic soil conditions and is suitable for the back of the border.
A third species is annual and is called Coreopsis tinctoria or Plains Coreopsis. It has small red flowers with a yellow border. It grows to about two or three feet and tends to attract syrphid flies. To give it more support, it can be planted amongst other plants. Monarda punctata is a good choice for a companion plant since they do well in mesic conditions and survive in slightly dry sandy soils. Coreopsis tinctoria will reseed itself each year.
The pink varieties of this genus come from Coreopsis rosea which requires more water than other species. In Canada, this plant is only native to Nova Scotia.
Some species of Melissodes have a close relationship with Coreopsis.