How to Plant and Grow Threadleaf Bluestar

This low-maintenance native perennial has beautiful blue flowers that resemble small stars.

Threadleaf bluestar (Amsonia hubrichtii) will be the star of your beds and borders for three seasons. This native perennial boasts clusters of pale blue star-shaped flowers in spring, fine green foliage through summer, and brilliant yellow-gold fall color. Indigenous to Arkansas, Missouri, and Oklahoma where it grow in meadows, this bluestar also attracts pollinators and offers the desirable features of deer resistance and low maintenance.

Where to Plant Threadleaf Bluestar

Use threadleaf bluestar in perennial border gardens, around patios and decks, and in native habitat gardens. This plant needs a modest amount of space where its upright stems, fine texture, spring flowers, and fall color can shine.

How and When to Plant Threadleaf Bluestar

Bluestar is a hardy perennial that may be planted whenever the ground is workable and the plants are available. Look for young bluestar plants at your local garden center or online nurseries. When planting, make sure to give your threadleaf bluestar enough room for it to grow 2-3 feet wide without crowding other plants.

Planted in groups of three to five plants, this bluestar adds a stunning design feature to your garden: When its brilliant yellow fall color draws all the yellow-leaved plants in your garden together, it creates a warm glow during chilling autumn weather.

Care Tips

Light

Plant threadleaf bluestar in full sun to get the most spectacular color and prevent flopping (which is especially important with taller varieties). In regions with very warm summers, plant bluestar in part shade.

Soil and Water

Threadleaf bluestar prefers fertile, well-drained soils. It’s more drought-tolerant than other Amsonia species, and doesn’t require constant moisture.

Pruning

If needed, cut back the stems by up to one-third after blooming to avoid stems leaning from the weight of the seedpods or when planted in more shady conditions. Leave the rest of the plant so you can enjoy upright stems full of green the rest of the summer, then brilliant yellow-gold leaves in fall.

Pests and Problems

Threadleaf bluestar is not susceptible to serious insect problems or diseases, although rust is a possibility.

Propagating Threadleaf Bluestar

Divide the plant in spring or take stem cuttings in early summer. Or let seeds fall to the ground, and move the seedlings wherever you like.

Types of Bluestar

Eastern Bluestar

Eastern bluestar (Amsonia tabernaemontana) produces large clusters of light blue star-shaped flowers in spring. This perennial attracts pollinators such as bees and butterflies. Eastern bluestar is also deer resistant and is hardy in Zones 3-9.

Fringed Bluestar

Fringed bluestar (Amsonia ciliata) has pale blue starry flowers that appear in mid-spring. The stems and new leaves have small hairs, hence the “fringed” part of its name. This bluestar tops out at 3 feet tall and is hardy in Zones 5-9.

Shining Bluestar

Shining or Ozark bluestar (Amsonia illustris) has narrow leaves that look shiny. Its ice-blue flower clusters appear in spring. It’s hardy in Zones 5-9.

Companion Plants for Threadleaf Bluestar

Butterfly Weed

Butterfly weed (Asclepias tuberosa) offers blooms in a complementary orange color that may overlap slightly with bluestar’s bloom time. This small to medium-size perennial works well in a wildlife garden because, like all members in the Asclepias genus, it provides food for the larvae (caterpillars) of the Monarch butterfly.

Peony

Peonies (Paeonia spp.) bloom in spring in shades of pink, red, yellow, and white. The big, bold flowers and coarse foliage contrast nicely with threadleaf bluestar. These plants are also deer-resistant.

Siberian Iris

Spring-blooming Siberian iris (Iris sibirica) complements threadleaf bluestar flowers with its own blue or purple flowers. Some varieties of this type of iris also come in white or yellow. The plants are deer-resistant and the flowers are great for cutting.