Liatris spicata ‘Kobold’
Finally, there is a native herbaceous perennial with an appropriate common name – blazing star. Not only do the individual flowers look like little miniature starbursts, this summer bloomer is an outstanding performer in sunny gardens.
Liatris spicata, in the Asteraceae family, is found in prairies and grasslands in the USA from the Gulf Coast to Canada (USDA plant hardiness zones 4-10).
I planted a cultivar of Liatris spicata into a perennial garden this past fall called ‘Kobold’ in northern Mississippi. This large flowered variety (Kobold means goblin) is supposed to stay compact and just over two feet in height. I thought it the perfect border plant along a sunny sidewalk along with Hemerocallis, Stokesia laevis, and Coreopsis. Sure enough, the linear basal leaves stayed under two feet tall but the flower spikes towered at four feet. Typically, this cultivar will average under three feet in height.
The roots of blazing star are tuberous corms and the planting area I selected had perhaps the worst soils I had seen for a garden. Each shovelful was a solid clod of blue and white mottled clay that refused to release its hold from the shovel tip. Although it is recommended to place into a well-drained fertile soil, I placed the top of the roots just at the soil surface and backfilled the clay soil tight up against the roots. Liatris performs best in slightly acidic soils from 5.5 to 6.8 pH.
As April warmed the garden soil, neighboring daylilies were already shooting up bright green leaves and coreopsis was already in bloom. The blazing star patch looked forlorn and empty. Around mid-May, thin wavering flower spikes of lilac-rose jumped above the surrounding border plants and bloomed well into August. Flowering time for Liatris will vary from summer into fall depending upon latitude, and can be a repeat bloomer. From the top of the spikes bright lavender flowers progressively opened down the stems.
Bright sulfur and swallowtail butterflies seemed permanently perched on the vertical stems. Hummingbirds guarded their territory around these plants and I actually saw a bumblebee sleep overnight on the flowers. The riot of bright purple flower stems against a backdrop of highlighter-yellow yarrows was, well, stunning. The flowers slowly faded to fuzzy seeds which were enjoyed by the goldfinches. Interestingly, the marauding nocturnal herds of urban deer did not touch this plant.
Growing blazing star is exceptionally easy. Just give it a sunny spot and well drained soils. Although I planted these in clay, it was in an area that was perched above the surrounding garden. I noticed that the Liatris I had planted near the wet drain swale were stunted and puny. In other words, the roots don’t like to stay wet, especially in winter. Other than that, these plants seem to thrive on neglect and prevalent humidity. I have not seen any insect or disease problems on these plants; although slugs, snails, stem rot, rust, and leaf spots have been reported to occur.
Liatris may be propagated through division or by seed. Divide tuberous corms in spring by separating with a sharp knife, being sure to leave one ‘eye’ on each division. Harvest mature seed stalks, allow to dry, and sow in fall with temperatures averaging 68 degrees. The seeds will germinate rapidly if covered thinly and kept moist. Fertilize with a medium strength fertilizer occasionally.
Combine ‘Kobold’ with yellow or purple coneflowers, butterfly weed, yarrows, verbena, allium, asters, or any other tough sunny perennials for a great summer display that butterflies will also appreciate. Just remember that even ‘dwarf’ plants will flourish to great heights when in a spot that they really like.