Amsonia Companion Plants

Amsonia provides three seasons of interest, making it a valuable perennial in a border or mixed bed. Mature plants reach up to three feet tall and wide and provide lush foliage during the spring, followed by star-shaped flowers by late spring and summer. In fall, the foliage turns a stunning yellow hue, rivaling the showiness of the flowers. 

Grow this herbaceous perennial in zones 3 through 9, creating a cottage or woodland-inspired space. For a color-coordinated planting, pair Amsonia with Russian sage, catmint, false indigo, or bluestem grass. Amsonia needs full or partial sun, rich soil, and weekly watering.

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Photo by DC Gardens, cropped, Flickr, copyright CC BY 2.0 DEED

Shrubs To Plant With Amsonia

Oakleaf hydrangeas are some of the easier hydrangeas to grow because they can handle more sun and humidity than their cousins, and are low maintenance once established. This plant thrives in zones 5 through 9 and features cone-shaped flower clusters during the summer and fall. The white flowers transition to a dark pink around late summer and fall. Spirea is another flowering shrub that works well with Amsonia because it has similar care needs. This summertime bloomer features flower clusters in shades of pink, red, or white, and the foliage puts on a spectacular display in the fall. Alternate Amsonia between oakleaf hydrangea or spirea shrubs, or plant each in rows to create a formal look. 

Make the Amsonia stand out by planting it with false cypress. The shrub’s evergreen foliage provides a consistent background of bright color while adding height and unique texture to a mixed planting. False cypress grows best in full sun, making it a good companion for Amsonia.

Perennials To Plant With Amsonia

Create a prairie vibe by planting amsonia with little bluestem grass. The North American native has an upright, rounded growth habit and blue-green foliage. The colorful foliage provides a subtle color match to Amsonia’s blooms while also providing a wispy texture.

Russian sage and catmint both add height and bluish-purple flowers to a space. Both of these herbaceous perennials have tall stems and an upright growth habit, similar to Amsonia, creating a consistent look across a foundation wall or mixed bed. False indigo is another perennial that has a similar growth habit but features tube-like flowers and attractive blue-green leaves that introduce color and a different texture.

Create a coordinated but less matchy space by planting coneflowers in a shared bed with Amsonia. The low-maintenance, daisy-like flowers add a burst of color throughout the growing season. The seed cones attract birds late in the season when the Amsonia displays dazzling foliage. Both plants have similar care needs and evoke a meadow or prairie feel. 

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Photo by K M, unmodified, Flickr, copyright CC BY 2.0 DEED

Annuals To Plant With Amsonia

Amsonia is a perennial, so it will come back each year, but it mixes easily with annuals, allowing a unique look each year. The vibrant flowers of cosmos and purslane have a similar rustic, prairie-like appearance to Amsonia. Cosmos and purslane do not grow as tall, so that the Amsonia will be on full display with these smaller plants placed in front. Another advantage of growing smaller plants with Amsonia is that more of the Amsonia will be visible during the fall when the foliage turns color.

Best Companion Plants For Amsonia in Containers

Plant Amsonia in a container with sunflowers to create contrast. Amsonia's smaller foliage and flowers stand out against the large leaves and bright yellow blooms of sunflower plants. When the Amsonia foliage turns yellow during late summer and early fall, it will complement the sunflower blooms, creating the perfect autumnal planter. Place the mixed container in full sun and water when the top few inches of potting mix is dry.

Plants Not To Grow With Amsonia

Amsonia needs full sun to grow best, although it can live in partial sun. Shade is unsuitable for Amsonia, so plants like coral bells and lungwort cannot grow alongside this perennial. Amsonia also does not tolerate wet feet and doesn’t grow well near cannas, calla lilies, and Egyptian papyrus grass.

Best Plants To Grow With Amsonia

Amsonia grows best with plants that crave full sun and have moderate water needs. Match Amsonia with spring and summer blooming plants, like oakleaf hydrangea, cosmos, or catmint, to create a lush cottage look. Select a shrub with bold fall color, like a spirea, to end the growing season with a big visual statement.

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Author Alison Cotsonas - Published 10-12-2023