If you’re looking for color over a long flowering period, then easy-going coreopsis is an ideal choice. New varieties really bring the color.
Coreopsis, also known as calliopsis and tickseed, originally comes from North and South America. Many of the 115 species are native to northern American prairies, and the majority of cultivated varieties also come from the USA. As you can see from the cute flowers, coreopsis is part of the daisy family (Asteraceae). The genus primarily comprises annual and short-lived shrubs known for their abundance of blooms.
Scientific investigations have shown that coreopsis species are closely related to the annual bidens (beggarticks). For this reason, there is increasing call to use one name for both genera. And the two do look very similar. While bidens is a popular balcony plant, coreopsis usually does best in a bed.
Appearance and Growth
All coreopsis species and varieties stand out with their colorful flowers, which cover these upright to bushy plants all over from June to October. Coreopsis gives you flowers forever! The large-flowered tickseed’s (Coreopsis grandiflora) eagerness to produce blooms is legendary The range of yellows offered by perennial coreopsis varieties has been expanded with new hybrids to include a plethora of colors - there are now varieties offering carpets of red, pink, white and red-brown, some double and some not. Varieties such as the annual plains coreopsis (C. tinctoria) caused a real sensation with the red ring on its yellow petals. The leaves of the coreopsis are usually very narrow, sometimes pinnate and may be basal on the stem depending on the species. Terminal heights vary dramatically: there are countless species that top out at between 3.94 and 31 inches in height but others, such as the Coreopsis tripteris, that reach a height of around 71 inches tall.
The lance-leaved coreopsis and the large-flowered tickseed (Coreopsis lanceolata and grandiflora) look very similar. The large-flowered tickseed tends to be longer in the stem, providing the best cut flowers. If you pick them fresh from the garden, they will keep in a vase for up to two weeks. In the bed, these golden-yellow beacons often keep their color for over eight weeks. Sterile and semi-double varieties such as “Early Sunrise” often flower even more tirelessly.
Location and Soil
Coreopsis loves sun! All varieties also need loose, humus-rich, nutrient-rich soil and don’t tolerate waterlogging. In their native eastern North America, they thrive in quite dry soil. In the garden, they therefore deal with dryness much better than their neighbors. The highest coreopsis (Coreopsis tripteris) grows up to 6 feet tall and prefers fresh soil on sunny, exposed land or the edge of woodland. The lance-leaved coreopsis, the large-flowered tickseed and the whorled tickseed (Coreopsis verticillata) prefer soil that is not too try.
Coreopsis is one of the most popular flowerbed shrubs thanks to its keen flowering. Threadleaf coreopsis are particularly popular. It grows as an upright shrub, forming filigree foliage that looks like a flowering mist. The warm yellow of these surface bloomers really sets off a joyous mood in late-summer borders. A ray of sunshine like the popular variety “grandiflora” can be combined with any sun-loving shrubs and flowering plants. Other prairie shrubs, such as echinacea, helenium and coneflowers (Rudbeckia) are popular companions. At just 12 inches tall, compact “Zagreb” is often a more suitable bed border. If you’re looking for a cooler yellow, opt for the sulfur-yellow “Moonbeam”. Coreopsis varieties with single flowers are popular insect magnets.
Colorful coreopsis are often offered as seasonal flowers. They are great for filling gaps in beds or adding a pop of color to balconies and patios. Unlike standard flowerbed plants, they tend to grow wider than taller.
Planting and Care
It’s best to plant coreopsis in spring. It is possible to plant them in summer, but you will have to water the plants well in the first few weeks after transplanting. As coreopsis loves nutrient-ruch soil, you should use compost to improve poor, sandy soil when planting.
Coreopsis are low-maintenance, easy-going flowerers. If taller vareties look like they may collapse, you can secure them to bamboo. In a bed, support frames will keep wobbly plants in shape. Compact varieties such as verticillata “Zagreb” and dense, bushy lanceolate “Sterntaler” stand up securely.
Coreopsis are generously flowering bedding shrubs that quickly overexert themselves. To rejuvenate them, they should be separated in spring after no more than three years, then planted out into fresh soil.
If you prune the large-flowered tickflower and the lance-leaved coreopsis back to the ground in early fall, you will shorten the flowering period but encourage the formation of overwintering rosettes. This will help the plants better weather the winter and live longer. Verticillata varieties are cut by two thirds in early October. You should also prune any withered flowering stems, as forming seeds reduces the production of new flower buds. Ideally, you should cut any stems that have already flowered close to the base. The flowers of semi-double and double varieties look unsightly once withered, so should be removed anyway if only for aesthetic reasons. Some varieties will bloom a second time when drastically cut back at the end of July.
You can propagate coreopsis through separation or basal cuttings in spring. Propagation through sowing seed is also possible for some species and varieties, particularly those with shorter lifespans. If you come across bags of coreopsis seeds in a store, they will usually be grandiflora varieties. These are sown in spring. You can begin sowing indoors in March. From the end of April, you can sow direct outdoors depending on your zone. Germinating indoors may be advisable, based on the species and variety: Then you can even look foward to flowers in the first year.
Diseases and Pests
Coreopsis can be infested by aphids. Young plants are often damaged greatly by slugs and snails. Powdery mildew also sometimes occurs. In principle, coreopsis is very robust and not overly susceptible to disease or pests.
Frequently Asked Questions
When do coreopsis sprout?
Coreopsis sprouts in spring and blooms from June to October.
How tall do coreopsis grow?
Depending on the species and variety, coreopsis plants usually grow to between 3.94 and 31 inches tall. Some even grow to 6 feet.
Is coreopsis a perennial?
Coreopsis plants tend to be annuals. But there are some shrubs with short lifespans.
Is coreopsis toxic?
Unlike many other shrubs, coreopsis is not toxic.