Description & Overview
White candelabra-like flowers bloom in July, lasting through August. Gray-green, upright foliage adds visual texture and height. Found throughout Wisconsin in moist prairies, savannas, and open woodland edges. Attracts butterflies, bees, wasps, and moths. May also be known as Culver’s-physic, Bowman’s root.
Core Characteristics
Category: Perennial
Wisconsin Native: Yes
USDA Hardiness Zone: to zone 3
Mature Height: 3-6 feet
Mature Spread: 1-2 feet
Growth Rate: Perennial
Growth Form: Perennial, upright, clump forming
Light Requirements: Full Sun
Site Requirements: moderate to moist soils, near water sources in full sun
Flower: Small, white, tubular flowers on slender spike-like racemes, not fragrant. A slight pink or blue hue to white flowers have been reported
Bloom Period: Mid-late Summer, July though August, sometimes into September
Foliage: Gray-green, whorls of 3 - 6 leaves, finely serrated margins
Fall Color: N/A
Urban Approved: Yes
Fruit Notes: Yellow seed capsule ages to dark brown by September. Seeds are wind dispersed (anemochory)
Suggested Uses
Culver’s root can be sited to a variety of conditions:
Rain Gardens: The natural ebb and flow of water levels in a rain garden are the ideal site for Culver’s Root. The more moisture, the taller the plant can grow.
Pollinator gardens: This plant can add height and mid-season blooms to your pollinator garden. Planting amongst sturdier species, such as Baptisia spp., or Wild Senna (Cassia hebecarpa), will provide the plant with some support against flopping over. Not an aggressive wildflower to where you will be regretting planting this unique native plant in your landscape!
The salt tolerance of Culver’s root is low to none; avoid planting in road ditches where salt use occurs.
Wildlife Value
Mid-Late summer bloomer – helpful for migrating pollinators, particularly monarch butterflies, as the blooms can last up to a month providing nectar ahead of a long migration. Learn more about how to attract monarch to your yard.
Short and long-tongued bees, as well as true honeybees, are the most frequent visitors as they indulge in the plant’s nectar and pollen. Other pollinators include bumblebees, mason bees, masked bees, sphecid wasps, butterflies, and moths. In particular, the larvae of the Culver’s root borer moth feed specifically on the roots of this plant.
The small seeds are of no interest to birds.
Maintenance Tips
Plants can be slow to establish in the landscape, not reaching their height and spread potential at around three years. Stems may need staking – this can be true especially if sited in a part-shade location. If you are finding this to be an issue, cutting back the flower stalk halfway mid-growing season to delay blooming will also help with flopping.
At the season’s end, although the seeds are not appealing to the birds, wildlife still benefits when old plants are not cut down in fall. Wildlife will find refuge and overwinter in plant litter, hibernate in stems, and any old plant matter will provide a ‘blanket’ for otherwise bare soil.
Deadheading/cutting back after flowering to about 6″ above the basal leaves will promote new foliage growth and potential rebloom later in the season.
Pests/Problems
Culver’s root is generally not bothered by pests, including deer and rabbits.
The larvae of the Culver’s root borer moth (Papaipema sciata) feed on the root. While it’s difficult to know how much of a threat this moth may to your Culver’s root, it is hardly worthwhile to spray or inject a pesticide on this pollinator-friendly native.
Leaf Lore
Veronicastrum: in honor of St. Veronica, -astrum meaning “false”, referencing the plant’s resemblance to Veronicas (Speedwell). Culver’s root is a member of the Plantain family – Plantaginaceae. Other members of this family include Penstemon, Veronica, and Turtlehead.
Named ‘Culver’s Root’ after Dr. Culver, a pioneer physician of the 18th century prescribed the bitter roots for their cathartic properties. Cherokee, Iroquois, Ojibwe, and Menominee peoples used Culver’s Root as an analgesic, laxative, emetic, treatment for coughs, and fevers.
Flower spikes bloom starting at the base of the inflorescence and move upward – blooming can last a month and are notably good cut-flowers.
Companion Plants
Summer-flowering plants:
- Rattlesnake Master (Eryngium yuccifolium)
- Leadplant (Amorpha canescens)
- Spotted Joe-Pye Weed (Eutrochium maculatum)
- Wild Senna (Cassia hebecarpa)
- Silphium spp.
- Ironweed (Vernonia fasciculata)
- Sweet Black-eyed Susan (Rudbeckia subtomentosa)
- Heath Aster (Symphyotrichum ericoides)
- Wild Bergamot (Monarda fistulosa)
- Big Bluestem (Andropogon gerardii)
- Hoary Vervain (Verbena stricta)
- St. John’s Wort (Hypericum kalmianum)
More plants for your rain garden:
- Swamp Milkweed (Asclepias incarnata)
- Spotted Joe-Pye Weed (Eutrochium maculatum)
- Wild Bergamot (Monarda fistulosa)
- Nodding Pink Onion (Allium cernuum)
- Buttonbush (Cephalanthus occidentalis)
- Silky Dogwood (Cornus amomum)
- Harlequin Blueflag Iris (Iris versicolor)
Written by Beth DeLain
