Arkansas blue star, or Amsonia hubrichtii, are spectacular flowering perennials native to the temperate southern central region that includes Arkansas and Oklahoma, thriving on rocky outcrops, prairies, floodplains and creek habitats.
This native perennial produces thin, needle-like green foliage that will help to fill borders in the spring and summer, although the real stars of the show are the pale blue flowers that emerge from dark-blue buds usually around mid-summer.
So, if you are looking to add an interesting native plant to your collection this year, consider learning how to grow Arkansas blue star. Here, one garden expert from Wisconsin shares all the information you need to plant and care for this attractive flowering perennial.
How to grow Arkansas blue star
While it is not as well-known as other species, Arkansas blue is surely a contender for one of the best perennials from North America. With an upright habit, the foliage with add vertical interest to any border, while pollinators will be sure to enjoy the nectar-rich blue blooms on display.
Growing habits of Arkansas blue star
'If you are looking for flowering plants that regrow every year, look no further than Arkansas blue star,' says Tabar Gifford, plant expert and American Meadows master gardener. 'This is a native garden favorite with soft, cloud-like foliage and pale blue, star-shaped flowers from late spring to mid-summer.
'Growing best in US hardiness zone 5 to US hardiness zone 8, Arkansas blue star became a popular and prominent native plant from the mid-20th century,' Tabar continues. 'In 1942 it was documented by naturalist Leslie Hubricht in its native range of the Ouachita Mountains of Arkansas and Oklahoma. Since then, it has become a garden favorite, prized for its tall perennial flowers, cloudlike foliage and brilliant fall hue.
'What's more, Arkansas blue star was deemed Perennial Plant of the Year for 2011, winning for its attractiveness and adaptability,' Tabar says. 'In addition, it is a larval host plant for the swallowtail butterfly, so if you are looking for ways to attract butterflies, this perennial is a good option. The nectar is also known to be popular with carpenter bees, bumblebees, and ruby-throated hummingbirds.'
Live Arkansas blue star plants are available at Walmart.
Grow Arkansas blue star plants from seed by sowing them in the fall and leaving them in a cold frame. You can then transplant in the spring.
Grow guide for Arkansas blue star
Soil: Arkansas blue star is relatively versatile and can be grown in most soils, including rocky, dry soil or waterlogged floodplains. However, they do better in 'soil that is well-draining but moist,' Tabar adds. Indeed, some moisture in the soil will help this perennial to thrive in the spring and summer months and reduce the need for frequent watering.
Light: While they will tolerate part shade, Arkansas blue star plants thrive in full sun borders that receive six or more hours of sunlight each day. 'The tall stems sport feathery foliage that steals the show in the fall, turning a hazy, golden yellow, especially when grown in a full sun yard,' Tabar says.
Watering: For young perennials that are newly planted, it is a good idea to carry out deep watering every two weeks in the first year while they establish. Annual mulching will also help to reduce the need for watering in the spring and summer months, helping to improve soil health and retain moisture in the ground. Try using this pine bark mulch, available from Walmart. Once established, however, this native is considered to be remarkably drought-tolerant.
Fertilizing: 'In general, this is a perennial that needs little to no additional fertilization,' Tabar says, 'especially if grown in rich soils that are mulched every year.' If you are concerned about plant nutrition, use an organic feed once a year during spring.
Pruning: 'After flowering, prune back Arkansas blue star by six to eight inches to encourage fuller, bushy growth for the remainder of the growing season,' Tabar says. Allow the golden foliage to stand through fall and winter, cutting the stems down to the ground once all the leaves have fallen, usually around December or January. As a perennial, your clump will reshoot in the spring from the base of the plant.
Toxicity: Although Arkansas blue star plants are not considered to be dangerous to humans or pets, the milky sap does contain alkaloids and is mildly poisonous. For this reason, it can irritate the skin during pruning, so be sure to wear gardening gloves, available from Amazon.
FAQs
Can I grow Arkansas blue star plants in pots?
While you can grow this perennial in a pot, I have found growing this in the ground tends to generate far better results. This is because Amsonia hubrichtii has a deep tap root, and grows better in deep soil. If you are going to grow this perennial in a pot, ensure that you use a tall vessel and monitor watering requirements through the spring and summer.
When is a good time to divide Arkansas blue star?
Learning how to divide plants is a fun and free way to grow your collection. As with most perennials, you can lift and divide Arkansas blue star clumps in the spring or the fall, using a sharp spade to slice larger clumps into two, three, or four sections. Just be sure that each new clump has a healthy root system from where it will produce new shoots.
Like many other native perennials, Arkansas blue star plants are virtually problem and pest-free. They are tough perennials that thrive without requiring much attention. For more native plant inspiration see our guide to the High Line in New York City, which grows this perennial alongside many other tough, pest-free species that grow in the wild across North America.
For more native perennial inspiration, see our guide to some of the best rudbeckias and fill your yard with striking yellow or red flowers next year.