The flowers turn the color determined by the cultivar, ranging from white to bright blue. The most popular Echinops purchased are the cultivars which turn a steel blue color. The color lasts for 5 - 8 weeks in bloom, and slowly fades as the plant goes to seed. However, if the stalks are left to go to seed, the color comes back when the seeds drop and it persists until the stalk is cut down.
Echinops is a hardy perennial in zones 3 - 8, however it more easily self-sows as the hardiness level increases. Some locations in higher zones feel as if it can be really aggressive with new seedling emergence every year. If that effect is undesired, it is very easy to deadhead the flowering stems and prevent seeding. If it is desired, keep an eye out in the spring for the seedling emergence and make sure to keep the ones where you want Echinops to grow and weed out the rest.
It prefers soils to be acidic, ranging from 5.1 – 6.5 in pH. It can tolerate drought, poor nutrients, and a wide variety of soil types, so long as it is well-drained. Echinops will not grow well if it is in an area that will hold onto water, or be in sitting water. It grows best in full sun, and pairs beautifully in companion plantings with other full sun summer perennials such as coneflower, phlox, bee balm, and catmint.