Cobalt blue wildflower has me smitten

  • The stunning blue flowers of gentians remain closed.

    The stunning blue flowers of gentians remain closed. Courtesy of Diana Stoll

By Diana Stoll
Posted9/8/2019 7:00 AM

It might happen at a botanic garden or while strolling around your neighborhood. A plant catches your eye and you know you must have it in your own garden.

It happened to me while visiting Olbrich Botanical Garden in Madison, Wisconsin, in September two years ago. Those cobalt blue flowers caught my eye and bam! I was smitten.


Gentians are wildflowers that grow on just about every continent. They were named after King Gentius of Illyria who is credited for discovering the medicinal properties of the roots of yellow gentian. Gentians have been used for centuries as a tea or bitters to improve digestion, stimulate appetite, treat stomachaches, heartburn, vomiting and diarrhea. It has also been utilized in wound care and soothing sore throats.

While I prefer opening the medicine cabinet over heading out to the garden, the medicinal qualities of gentians do not appeal to me. However, if they do to you, do plenty of research before ingesting any parts of plants from the garden.

There are several types of gentians native to the Midwest.

Gentiana andrewsii, commonly called bottle or closed gentian, slowly grows 1 to 2 feet tall and almost as wide. It prefers a partly shaded or mostly sunny spot in the garden with consistent moisture and is often found growing naturally along streams or ponds or in moist woodlands. Bottle gentian cannot, however, survive in soggy or very dry soil.

Their magnificent, deep blue flowers bloom in clusters at the top of stems in September and October. The flowers are tubular, resembling oversized flower buds. Their petals remain closed and require the strength of bumblebees to force their way through the tiny opening at the tip of the flower for pollination.

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Plant bottle gentian in a woodland garden or at the front of a border with protection from hot afternoon sun. Appropriate bedfellows include sedges (Carex spp.), blazing star (Liatris spicata) and Siberian irises.

Gentiana alba (sometimes listed as Gentiana flavida), or cream gentian, is similar in size and stature but sports white, greenish white or yellowish white flowers. It blooms about three weeks earlier than bottle gentian and the petals of its flowers open up just a bit. A spot in full sun will produce the most flowers but will also yellow the foliage.

Fringed gentian, or Gentianopsis crinita, is another gentian family member. It is a biennial, forming a low rosette of foliage the first year and producing flowering stems the next. It replenishes itself by self-seeding.

Fringed gentian grows from 1 to 3 feet tall. The plant gets its common name from its showy bright blue or bluish-purple flowers with fringed petals that bloom from late summer into fall.


The flowers of this gentian are not shy about opening their petals, as long the sun is shining. On cloudy days, they remain closed. Fringed gentian grows best in full sun and prefers to grow in wetter conditions.

Gentians have no serious problems with insects or disease. Their foliage is not palatable to deer, rabbits or other four-legged garden guests.

• Diana Stoll is a horticulturist, garden writer and speaker. She blogs at

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