Dense Blazing Star (Liatris spicata)

Blazing Star, Blazing Stars, Dense Blazing Star, Dense Button Snakeroot, Gayfeather, Marsh Blazing Star, Sessile-headed Blazing Star

Liatris spicata is a plant naturally growing in prairie areas. It forms a characteristic dense cluster of leaves above the ground, from which a vertical spike grows. That’s where blazing star flowers appear. Gayfeather is a highly valued element of many garden arrangements. It is amazing with a great number of melliferous flowers which attract many beneficial insects.

I. Appearance and Characteristics 

Liatris spicata, the dense blazing star, prairie feather, gayfeather or button snakewort, is a herbaceous perennial flowering plant in the family Asteraceae. It is native to eastern North America where it grows in moist prairies and sedge meadows.

The plants have tall spikes of purple flowers resembling bottle brushes or feathers that grow 1–5 ft (0.30–1.52 m) tall. The species grows in hardiness zones 3 – 8, stretching from the Midwest to the East Coast, eastern and western Canada.

Common varieties include ‘Alba’ and ‘Floristan White’ which are white-flowering cultivars on 18 in (46 cm) tall spikes, ‘Callilepsis’ with long stems good for cut flowers, ‘Floristan Violett’ with a strong stem and thick, violet flower spikes preferred by florists, and ‘Kobold’ which stays small in size with deep purple flowers.

Liatris spicata var. resinosa is found in the southern part of the species’s natural range. The variable plants have only 5 or 6 flowers per head and the heads are more widely spaced on the stems; these differences are more pronounced when the plants are found in drier and coastal habitats.

Liatris spicata is a garden flower in many countries around the world, grown for its showy purple flowers (pink or white in some cultivars). They bloom in July through August or September, depending on where in their range they are located.

Under cultivation it is found under many names including button snakewort, Kansas gay feather, blazing star, Liatris callilepis.

Full sun is best and well-drained soil is preferred to prevent rot, though the plants do prefer moist soil. However, the plants do not tolerate wet soil in winter. The plants can tolerant some shade as well as drought but need regular watering during the first growing season to build strong roots.

Plants can be grown from corms (similar to bulbs and tubers) or from seed, or the plants can be bought at garden centres or nurseries.

II. How to Grow and Care

Sunlight

The dense blazing star will grow in full sun and partial shade. It is most commonly grown in full sun, which encourages full growth, though most will also grow under a little shade. However, too much shade may prevent blooming and can also lead to disease. The dense blazing star will survive and thrive in bright sunlight and hot summers, with at least six hours of sunlight a day needed for optimum growth.

Temperature and Humidity

Hardy in zones 3 to 9, Liatris is quite tolerant of summer heat and humidity in warm climates, and will nicely survive very cold winters provided that soil is not too wet. Wet winter soils can cause the corms to rot.

Watering

Water should be applied sparingly when the bulbs begin to sprout. The bulbs will not need much water during this period, and excess water could lead to unwanted soil-borne diseases. More water can be applied as the bulbs finish sprouting and the plants begin to grow. Soil should be kept moist to the touch. During the winter, watering can be reduced to avoid soggy soils, which can lead to the overwintering of diseases.

Soil

Just about any soil, at any level of fertility, will successfully grow Liatris corms, although quick drainage is essential to prevent rot. Very rich soils may require that you stake the plants, as the stalks can be a bit floppy. Liatris plants prefer a slightly acidic to neutral soil pH. Heavy clay can cause root rot, especially in winter, if the soil doesn’t drain well.

Fertilizing

Grown in healthy enough soil, the dense blazing star does not need fertilizer. However, a little fertilizer can be added prior to new growth in the spring, or if growth is slow in the spring. An all-purpose fertilizer can be used according to package directions. A slow-release fertilizer can also be added at the bottom of the hole at time of planting to aid initial growth. In rich soils, the dense blazing star is unlikely to need any fertilizer.

Planting Instructions

When planting, the soil should first be covered with a 5 cm layer of compost. A 10 cm hole should then be dug through both the compost and soil underneath for each dense blazing star plant, with holes for each plant set 10 cm apart in each direction. Once the corms are placed and the soil tamped down over the bulbs, a thorough watering should be applied to settle down the soil. The bulbs should begin to develop roots and sprout within a few weeks. Despite its long stems and flowers, the dense blazing star rarely needs staking and self-supports unless its soil is soggy.

Pruning

It is important to deadhead the dense blazing star as flowers begin to fade. As soon as flowers start to fade, stems should be cut back to basal stems to prevent the plant from going to seed and ending its blooming season early. Pruning the stalks at the end of the season helps to stimulate vigorous growth for the following season. End of season pruning should be done by cutting the stalks back to 5 to 10 cm above the ground and covering the stalks with leaves or straw.

Propagation

As a Liatris plant matures, it typically develops offset corms. Liatris is quite easy to propagate by digging up the root corms and separating them. Doing this every few years will also help rejuvenate the plants and extend the life of a clump. Here’s how:

  • In spring as new growth is just beginning, use a shovel or trowel to dig up the entire clump.
  • Separate the clump into sections, each with at least one thick corm with at least one “eye” or bud. Discard any corms that are soft or completely desiccated.
  • Plant the corms immediately in their new locations, after carefully loosening the soil to at least 5 inches deep. Space pieces at least 1 foot apart to ensure good air circulation. Corms can also be divided in fall, then stored over winter for spring planting.
  • Other Liatris species tend to grow from rhizomatous roots rather than corm structures. With these, propagation is a matter of cutting the rhizomes into large sections for replanting.

How to Grow from Seed

Liatris is not hard to start from seed, either from purchased commercial seed or from the tiny seeds you collect from the dried flower heads in late fall. (Note: if you collect seeds from a hybrid cultivar, the plants will not come true to the parent.) But be aware the seeds will require 4 to 6 weeks of cold stratification in order to germinate. This can be achieved if you direct sow the seeds in the garden in the fall, or if you store the seeds in the refrigerator before planting them in indoor starter trays six to eight weeks before the last spring frost.

If starting indoors, plant the seeds in small pots or starter trays filled with standard potting mix. Moisten the mix, then plant the seeds in groups of three to five seeds, just barely covering them with additional potting mix. Place the containers in a spot that receives morning sun and where nighttime temps remain above 50 degrees Fahrenheit. Keep the potting mix moist until the seeds sprout, which usually takes two to four weeks.

Keep the seedlings moist as they grow in a sunny location until it’s time to transplant them outdoors after all danger of frost has passed. Harden off seedlings before planting them in the garden. New seedlings may need protection from feeding rabbits for the first year. When planted from seeds, Liatris usually does not bloom until the second year.

Potting and Repotting 

Native perennials such as Liatris are not commonly grown in containers, but it is certainly possible to do so. Any well-draining container filled with a good porous potting mix will work for growing Liatris. Planting and care are identical for in-ground plants, but you will probably need to water more often, as the soil in containers tends to dry out faster than garden soil.

To ensure winter survival, move the containers to a sheltered location as freezing weather sets in. Some gardeners have success placing containers in a cold frame or cool garage, heaping them with mulch, or even burying the container in the garden for winter. But don’t try to bring a potted Liatris indoors to grow as a houseplant over winter, as these plants require weeks of cold dormancy in order to reset themselves for spring growth.

Overwintering

Within its hardiness range, Liatris needs no special winter cold protection. The normal routine is simply to cut off the flower stalks near ground level, though you can also leave the flower heads in place for the benefit of winter feeding birds.

Liatris does not like wet winter soil, so it’s best to avoid heaping mulch over the plant crowns for the winter, as this can trap moisture and encourage bulb rot. And make sure to clean away soggy garden debris in the spring before new growth begins.

Pests and Diseases

  • Common Plant Diseases

Liatris does not suffer from any serious insect problems, but several fungal diseases can occur, including leaf spot, rust, stem rot, powdery mildew, and verticillium wilt. The best approach is to prevent these diseases by giving the plants good sunlight and air circulation. Mild fungal diseases, such as leaf spot and powdery mildew, are usually not serious and may not even require treatment. More severe diseases sometimes can be treated with fungicides but may be necessary to remove and destroy badly affected plants.

  • Common Problems With Liatris

As a hardy native wildflower, Liatris generally thrives with relative neglect. When problems occur, it is often the result of too much care—too much soil fertility or too much watering.

Flower Stalks Flop Over

Liatris is a plant that is quite sturdy when growing in average or poor soils, even rocky, gravelly soil. In most cases, staking the plants is not necessary. But paradoxically, very rich, fertile soils can cause the flower stalks to topple over. In this case, you may need to stake up the flower stalks; and you can probably safely reduce or eliminate your feeding routine.

Plants Turn Mushy, Break Off at Ground Level

This is the classic symptom of stem or corm rot, caused by wet soil that introduces fungal disease into the roots or stems. These plants will need to be removed. Future problems can often be avoided by reducing water or improving the drainage of the soil.

III. Uses and Benefits 

  • Ornamental uses

The dense blazing star is prized for its ornamental flowering spikes and is often grown within perennial borders of prairie gardens as a vertical accent. It is also great for cottage and native plant gardens because of its low care requirements. The plant is well accompanied by plants such as rudbeckia and echinacea. Grasses such as fountain grass and Mexican feather grass also are flattering accompaniments to the dense blazing star.

  • Role in ecosystems

Liatris spicata is excellent for attracting pollinators and beneficial insects. These include butterflies such as the monarch, tiger swallowtail, clouded sulfur, orange sulfur, gray hairstreak, Aphrodite fritillary, painted lady, red admiral, and wood nymphs. The flowers attract bumblebees, digger bees (Anthophorini), long-horned bees (Melissodes spp.), leaf-cutting bees (Megachile spp.), skippers, and birds including hummingbirds. Caterpillars of the rare glorious flower moth (Schinia gloriosa) and liatris flower moth (Schinia sanguinea) feed on the flowers and seeds. Caterpillars of the liatris borer moth (Carmenta anthracipennis) bore through the plant’s stems. Groundhogs, rabbits, and voles also eat the plants.

Deer are less likely to eat Liatris spicata than other plants and therefore considered deer-resistant, although deer will eat almost anything when food is scarce.

  • Medicinal uses

Liatris spicata was historically used medicinally by Native Americans for its carminative, diuretic, stimulant, sudorific, and expectorant properties. In addition to these uses, the Cherokee used the plant as an analgesic for pain in the back and limbs and the Menominee used it for a weak heart. The root of the plant is the part most often used. Native Americans also used the plant to treat swelling, abdominal pain and spasms/colic, and snake bites. Currently, the plant is used for a sore throat by gargling an infusion, as an herbal insect repellent, and in potpourri.

IV. Harvesting and Storage

Once blooming is finished later in the year, seeds can be collected easily. For collecting seeds, a stalk can be cut off once it has finished blooming and has dried. The seeds can be stripped from the stalk by hand.

Dense Blazing Star (Liatris spicata) Details

Common name Blazing Star, Blazing Stars, Dense Blazing Star, Dense Button Snakeroot, Gayfeather, Marsh Blazing Star, Sessile-headed Blazing Star
Botanical name Liatris spicata
Plant type Bulb
Hardiness zone 3a, 3b, 4a, 4b, 5a, 5b, 6a, 6b, 7a, 7b, 8a, 8b
Growth rate Medium
Harvest time Fall
Height 3 ft. 0 in. - 6 ft. 0 in.
Width 3 ft. 0 in. - 6 ft. 0 in.
Sunlight Full sun (6 or more hours of direct sunlight a day)
Soil condition Clay
Flower color Pink
Leaf color Green