Zone: 3 to 8

Soil: sand to loam

Light: Full sun to part sun

Bloom colour: lilac, mauve, purple, white

Bloom period: August into September

Height: 1.5 to 5 feet

Moisture: Varies (see note below)

Attracts: Especially attractive to monarchs as well as some other butterflies and bees.

Notes: Mid to late summer is the season for Liatris which is a native plant that produces some of the finest cut flowers in North America. Unusually the inflorescences are spikes that flower from the top downwards and do so for several weeks. Each composite flower is made up of only disc flowers which are purple or magenta. There are three basic forms of Liatris. L. cylindracea has a short flower spike with a few flowers at the top of the stem. L. spicata and L. pycnostachya have flowers that are whorled on a long spike. Other species have a spike that is made up of pairs of flowers that are slightly offset from each other (see picture). Blazing stars do not spread through their roots and you will not find them growing in large patches unless they have been planted that way. They are promoted as great plants for pollinators but they are somewhat overrated.

In terms of ability to attract Monarchs, here is a suggested ranking based on observation:

1) Liatris ligulistylis
2) Liatris aspera and Liatris scariosa
3) Liatris cylindracea
4) Liatris pycnostachya
5) Liatris spicata

The most common species planted in gardens is L. spicata which does not attract monarch butterflies anymore than many other native plants. The top visitors for this plant tend to be skippers and bees. If monarch butterflies find L. cylindracea, they will remain and feed on them for some time. L. ligulistylis is the only one of these species where you can plant a single specimen and expect several or many Monarch butterflies to find it. This plant has to be releasing a significant amount of chemical attractant to be so much better than all other plants in attracting monarch butterflies. It would not be unreasonable to suggest that the chemicals released by the plant are similar to the chemical released by the butterflies themselves to attract each other.

Liatris spicata (Marsh Blazing Star) as the name suggests, prefers ample water and fertile soils but can survive surprisingly well in dry sandy soil with little bit of watering. This species is the most popular liatris on the shelves because its stem is crowded with flowerheads and its adaptability makes it an easy choice for a gardener. You are more likely to see bees than butterflies on this species.

Liatris ligulistylis prefers slightly moister and richer soils than Liatris spicata and it does not tolerate drought so well. L. ligulistylis equally does not like flooding and like all the species featured here, it needs a well drained soil to survive the winter.

If you have dry conditions, then you might want to consider L. aspera and L. scariosa var. nieuwlandii as alternatives. L.aspera likes it dry, hot and sunny whereas L. scariosa var. nieuwlandii tolerates more shade and is more likely to be found in oak savanna. These species are similar to each other, but the flowers of L. aspera are sessile or short stalked whereas L. scariosa has flowers on long stalks. Both of these plants are a little bit shorter than the other aforementioned species, growing up to 4 feet high.

Liatris cylindracea is the smallest and least attractive of the species mentioned here. The individual flowerheads are stunning but they are sparsely distributed at the top of the stems. This Liatris may be your best choice though in dry sandy soils where other species cannot thrive. Plant it amongst groups of Monarda punctata as the flowers of this Liatris will peek through or try planting it en masse at the front of the border.

No Liatris should be planted in clay soil because there is a high chance of root rot killing the corms over the winter. For L. pycnostachya and L. spicata, you might be able to get away with a clay loam soil. Whatever soil you use, it must be well drained. If you have dry sandy soil, then try planting Liatris aspera, Liatris cylindracea, or Liatris scariosa. Liatris punctata is a smaller species that survives drought with really deep roots. It is not native to the province of Ontario, but it is available in some nurseries.

If you want an extended season of Liatris in your garden then plant L. cylindracea which flowers earlier and L. scariosa which flowers later than all the other species.

The members of this genus do not have particularly attractive leaves. Therefore, excepting L. punctata and L. cylindracea due their smaller size, these plants are best planted either between plants or behind plants. All the species mentioned are native to Canada or are near-natives. The species native to Ontario are L. aspera, L. cylindracea and L. spicata. Please note that there are many common names for members of this genus, so it is better to use scientific names when referring to any species of Liatris.