The whorled tickseed inspires with exuberant and long blooms in bright yellow. It enjoys a location spoiled by the sun and even accepts dryness.
Profile of whorled tickseed:
Scientific name: Coreopsis verticillata
Plant family: daisy family (Asteraceae)
Other names: whorled coreopsis, thread-leaved tickseed, thread leaf coreopsis
Planting time: spring
Flowering period: June to September
Soil quality: sandy to loamy, lime sensitive, nutrient rich, humus rich
These information are for temperate climate!
Use in: flowerbeds, flower bouquets, borders, flower garden, prairie garden
Winter hardiness: hardy, USDA Plant Hardiness Zones: 6 (-20 °C / -5 °F)
Bee and insect friendly: Yes
Plant characteristics and classification of whorled tickseed
Plant order, origin and occurrence of whorled tickseed
The whorled tickseed, with botanical name Coreopsis verticillata, has its home in the southeast of the USA. It belongs to the genus of tickseed (Coreopsis) with annuals and partly woody perennials at the base, which are mainly found in grasslands of North and Central America and in Mexico. The perennial, also known as whorled coreopsis, thread-leaved tickseed or thread leaf coreopsis, is very popular with gardeners because of its long and rich flowering and its drought resistance. It belongs to the daisy family (Asteraceae).
Characteristics of whorled tickseed
The whorled tickseed is a bushy perennial with numerous branched shoots. It grows between 40 and 60 centimeters (16 to 24 in) high, depending on the variety. It spreads slowly over rhizomes. In contrast to its “relatives”, Coreopsis verticillata is extremely long-lived and forms regular stands over the years.
The triple pinnate leaves are up to 6 centimeters (2.4 in) long, whereby the linear leaves, which are about 1 to 2 centimeters (0.4 to 0.8 in) long, are filigree and medium green in color. The species name “verticillata” refers to the whorled leaf position.
The terminal flowers are arranged in umbrella panicles. They appear in early summer and provide bright spots of color in the bed until September. The individual flowers are reminiscent of Mexican asters or daisies. Depending on the variety, they shine in different shades of yellow and are up to 5 cm (2 in) tall. A small yellow eye is typical of all varieties. The flowers are very popular with bees.
The fruits of Coreopsis verticillata are seeds without pappus.
Whorled tickseed – cultivation and care
The whorled tickseed prefers pure sunshine, but the joy of flowering diminishes considerably in partially shady areas. The water requirement is low to medium, accordingly a dry to fresh location is desired.
As far as the soil is concerned, the whorled tickseed has certain requirements. It should be loose, humusy and well supplied with nutrients. It does not tolerate waterlogging at all, the soil should be rather lime-free.
The whorled tickseed is best planted in small groups of three to five, and if there is enough space, also in larger groups. Soil compaction in the subsoil should be corrected by incorporating coarse sand or gravel. A poor soil can be improved by adding compost. Planting time is practically all year round, in spring the growth success is highest.
Care / Watering / Fertilization / Pruning
Regularly removing faded flowers and their stems stimulates the whorled tickseed to form new buds and thus prolong the flowering period. At the beginning of October the perennial should be cut back to a third of its height. In the spring, the perennial is cut back to the ground again. A subsequent composting stimulates new shoots. Watering is only necessary on hot and dry days. Before the winter, the perennial can be mulched a little to protect it from frost.
The best time to divide the rootstock is early spring.
Coreopsis verticillata can be easily propagated by cuttings and division of the rootstock. The greatest growth success is in spring.
Diseases and pests
For snails, young plants of the whorled tickseed are a natural food, and aphids can also be a problem. Otherwise, the perennials are very robust and above all very drought tolerant.
The whorled tickseed is hrady down to -20 °C / -5 °F. The perennial can be protected from frost by a layer of mulch.
Use in the garden
The whorled tickseed fits well in natural borders, prairie gardens as well as in gravel beds. It can be combined with perennials that have similar site requirements. Thus, for example, the dense blazing star (Liatris), prairie mallow (Sidalcea), coneflower (Rudbeckia) or purple coneflower come into question. The prairie becomes optically closer if grasses such as switchgrass (Panicum virgatum) are planted in addition. The perennial also looks pretty in front of a backdrop of red-leaved woody plants. Particularly low varieties are also suitable for tub planting. In the vase, the whorled tickseed also comes into its own.
- The 60 centimeter (24 in) high ‘Grandiflora’ revels in a rich golden yellow.
- ‘Moonbeam’ is characterized by particularly large flowers in cream to sulphur yellow.
- The light yellow ‘Zagreb’ grows to a maximum height of 40 centimeters (16 in) and is particularly robust.
- A bright red with orange tones is offered by the variety ‘Broad Street’.
- ‘Route 66’ has a yellow head, the florets are dark red in the center, towards the tips the color fades and gradually changes to a cream yellow.