Ornamental · Asteraceae
Stokes Aster
Stokesia laevis
A native perennial crowned with fringed, lavender-blue flower heads over glossy green leaves.
Full sun
Every 5–10 days
USDA 5–9
12–24 in · 30–61 cm
Overview
Up close, Stokes aster carries a bloom unlike most daisies. Each fringed, daisy-like head is edged with slender, fringed petals that give the flower a soft, feathery outline, colored lavender-blue, white, or creamy yellow. The heads rise from a low rosette of glossy, strap-shaped leaves, and the whole clump-forming plant is a southeastern United States native named for the botanist Jonathan Stokes.
The flowers themselves make a real statement, stretching up to 5 inches (13 cm) across, wide enough to fill a hand, and opening in early summer. Their fringed rays crowd together into dense, ruffled heads that draw bees and butterflies to the center. When the blooms fade, the glossy rosette stays green and low through mild winters, its strap-shaped leaves holding their shine.
Each flower rides on a slender stem above the leafy base, upright until a heavy bloom and a soaking rain tip it sideways. The plant spreads slowly into a widening clump, and the one weakness written into it is a crown that rots in cold, wet soil. Give the roots sharp drainage and that low, glossy rosette returns and broadens year after year.
Care
The short version: set it in full sun and average, well-drained soil, keep it watered through the growing season, and keep it dry over winter, since cold, soggy soil rots the crown and kills the plant.
Light
In full sun, the stems firm up and the fringed heads open at their fullest and most numerous. The plant takes partial shade, but in heavy shade the stems stretch thin and pale, lean over, and carry fewer blooms.
Water
Keep the soil at average to medium moisture through the growing season, watering about every 5 to 10 days when rain is scarce. What the roots cannot stand is standing winter water, which softens and blackens the crown, so drainage matters far more than the exact timing.
Soil
The plant settles into average, well-drained soil and shrugs off sandy ground and a little summer wetness. Hold the pH between 5.5 and 7.0, and on ground that stays soggy, open up the drainage before anything else so the crown stays firm.
Temperature
This is a hardy perennial, holding from about -20°F to 95°F (-29°C to 35°C) and reliable across USDA zones 5 through 9. The glossy rosette takes southern heat and humidity without scorching, and a winter mulch shields the crown at the colder edge of its range.
Humidity
Ordinary outdoor humidity leaves the foliage untroubled, so there is no level to chase. Moving air matters more, drying the strap-shaped leaves and keeping the crown sound.
Feeding
Feed it sparingly. A single spring feeding of balanced fertilizer, or a scattering of compost, is all the rosette needs, since a heavier hand only draws up soft, floppy stems that cannot hold their heads.
Pruning
Cutting off the faded heads keeps fresh fringed blooms coming and clears any tattered, browning leaves from the rosette. Every few years, lift and split the clump to keep the crown dense and full.
Repotting
A potted plant needs moving only when roots fill the container or the crown grows congested and the flower count falls. In the ground, splitting the clump every 3 to 4 years keeps that crown open and productive.
Size & spacing
The clump stands 12 to 24 inches (30 to 61 cm) tall in flower and spreads 12 to 18 inches (30 to 46 cm) wide at the base. Set plants about that far apart so air slips between the rosettes and each one has room to broaden.
When to plant
Stokes aster keeps a warm-season pace. Seed goes in indoors in late winter, plants move outside in spring after frost, and the fringed heads unfurl from early summer into July, with the low rosette often pushing a second round of blooms in fall.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Sow: Late winter to early spring (about 6-8 weeks before last frost)
- Plant: Spring after danger of frost has passed
- Harvest: Early to mid summer (May to July), sometimes reblooming into fall
Hardiness
USDA hardiness zones: 5–9
Temperature: down to -29°C
Troubleshooting
Stokes aster stays close to trouble-free, so the signs are few and easy to read on the plant. Leaning stems and holed leaves are only skin-deep, while a soft, blackened crown after winter is the one that kills. Match what you see below and deal with the serious one quickly.
A soft, blackened crown after winter
When a plant never pushes new leaves in spring, look for crown rot at the base, where cold, waterlogged soil has turned the roots and crown soft and dark. This is what kills more Stokes asters than any pest. Dig out the rotted crown, lift the drainage onto a raised bed or slope, and lay a winter mulch in colder zones to keep the crown dry.
Fix:
- Improve drainage by amending soil or planting on a raised bed or slope
- Remove and discard rotted crowns
Bloom-laden stems bowing to the ground
The trouble starts with top-heavy heads that soak up rain and wind until the slender stems bow and splay across the soil. Shade and rich soil make it worse, drawing up soft growth that never stiffens. Full sun, a lighter hand with feeding, and a grow-through support under the taller cultivars hold the stems straight before the heads open.
Fix:
- Provide light staking or grow-through support for tall cultivars
- Site in full sun to promote sturdier stems
- Avoid over-fertilizing
Notched, hole-punched leaves
Ragged holes chewed through the glossy leaves, with dark specks of frass alongside, point to caterpillars feeding. The damage marks the foliage but rarely weakens the plant, which keeps flowering and feeding pollinators. Lift the caterpillars off by hand and leave the leaves to grow out.
Fix:
- Handpick caterpillars
- Tolerate minor feeding as the plant supports pollinators and is generally pest-free
Toxicity
For homes with pets and children, Stokes aster is non-toxic in every part, from its glossy leaves to its fringed flowers. No extension or botanical source lists it as poisonous, and none report skin irritation, so it is safe wherever a curious nose or hand reaches it.
Safe for
People · Cats · Dogs · Horses · Rabbits · Livestock · Birds
Cats None
No toxicity is on record for cats, so a nibble at the fringed heads or glossy leaves does no harm. A cat that eats a large amount of any plant may bring a little back up or run a brief upset stomach, the same as after chewing grass.
Dogs None
Dogs are safe with the plant, which holds no poisonous compounds in leaf, stem, or flower. A big mouthful might bring nothing more than mild, passing stomach upset.
Horses Safe
No toxicity warnings cover horses, so the plant can grow along a pasture border or in any bed within their reach.
Rabbits Safe
Rabbits can chew the strap-shaped leaves without harm, since the plant carries no toxins. They graze the foliage and flowers eagerly, though, so a low fence keeps the heads intact.
Livestock Safe
Cattle, goats, and sheep face no poisoning from this plant. No extension or botanical source lists it among those that harm grazing livestock.
Birds Safe
Birds are safe around it. The fringed flowers pull in bees and butterflies, and seed-eating birds can pick over the dried heads with nothing to fear.
People Safe
The plant is non-toxic to people, with no reports of poisoning or skin irritation from handling it. It is not grown as food, so no part is eaten, but an accidental taste does no harm.
No special handling precautions noted; wash hands after gardening as general practice.
Varieties
The named Stokes asters set themselves apart by the color and size of their flower heads. These are the ones you will see most often.
Blue Danube
A compact plant whose lavender-blue heads swell to an outsized 5 inches (13 cm) across.
Alba
Its ray florets open clean white, a cool alternative to the usual blue coloring.
Mary Gregory
The fringed heads come in a pale, creamy yellow, a rare tint on a plant that otherwise runs blue.
Peachie's Pick
A compact selection that opens deep blue heads in quantity over a long season.
How to propagate
Stokes aster is easy to multiply from its own clump, seed, or cuttings.
DivisionEasy
Spring (or early fall) · One growing season
The simplest route is to lift the clump and split its crown in spring, or early fall if you prefer. Repeated every few years, it also refreshes an aging clump as the center thins out, and each split piece roots in over a single growing season.
SeedModerate
Spring; readily self-sows in the garden · Blooms typically in the second year from seed
Seed can start indoors in late winter or drop straight into the ground in spring, and the plant will scatter its own seed around the garden. The wait is the price, since seedlings usually hold back their first flowers until the second year.
Stem cuttingsModerate
Growing season · Several weeks to root; root cuttings are also effective
Stem cuttings taken while the plant is in growth root over several weeks into new plants. Root cuttings work as well, so a length of the rootstock will also send up a fresh plant.
Myths
Stokes aster is a true aster and belongs to the genus Aster.
The look of the flower fools the eye. The plant stands in its own genus, Stokesia, named for the English botanist Jonathan Stokes, and it meets the true asters only within the wider daisy family. Fringed and blue as the head appears, the plant is a relative rather than a genuine Aster.
Stokes aster wants soil that stays soaking wet, since it grows wild in bogs and savannas.
The plant does drink up damp ground while it is in leaf and growing, which is the root of the bog story. Even so, the crown demands good drainage, and wet winter soil rots it faster than anything else. Water it freely in summer, then let the base sit dry through the cold.