Photo: Kathleen Houlahan ChayerCC0via Wikimedia Commons
Smooth Blue Aster Plant Care
Symphyotrichum laeve (L.) Á.Löve & D.Löve
Updated · Sources · How we source care data
This plant is adorned with slender, lance-shaped leaves and clusters of small, daisy-like flowers. Originating from North America, this species is highly sought after by plant collectors for its delicate appearance and ability to attract pollinators to the garden.
Every 7–10 days
Full sun to partial shade
50–80°F
40–70%
At a glance
How do you care for Smooth Blue Aster?
Water Smooth Blue Aster every 7–10 days, letting the top layer of soil dry out between waterings, and give it full sun to partial shade. It prefers temperatures of 50–80°F (10–27°C) and 40–70% humidity. Fertilize it every 6 months during the growing season.
Where Is the Smooth Blue Aster Native To?
What Is the Smooth Blue Aster?
Smooth Blue Aster (Symphyotrichum laeve) belongs to the Asteraceae family within the Symphyotrichum genus. Smooth Blue Aster is native to Canada, the United States, and Coahuila (Mexico). Smooth Blue Aster is also known as Smooth Aster, Glaucous Blue Aster, Aster laevis.
Smooth Blue Aster displays an upright, bushy perennial growth habit, reaching up to 3 ft tall with a spread of approximately 2 ft. Smooth Blue Aster produces daisy-like flowers in various colors like purple, blue, pink, and white.
Leaf size: approximately 4 inches.
How Often Should You Water a Smooth Blue Aster?
Symphyotrichum laeve requires watering every 7–10 days. Allow the top layer of soil to dry between waterings to prevent root rot. Reduce watering frequency during winter when growth slows.
Watering Frequency
Every 7–10 days
Let soil partially dry between waterings
What Light Does the Smooth Blue Aster Need?
Smooth Blue Aster thrives in full sun to partial shade.
Light Requirement
Full sun to partial shade
What Temperature and Humidity Does the Smooth Blue Aster Prefer?
Symphyotrichum laeve grows best at temperatures of 50–80°F. Smooth Blue Aster prefers humidity levels of 40–70%.
Temperature
50–80°F
Humidity
40–70%
What Soil Mix Works Best for a Smooth Blue Aster?
Well-draining loamy soil with added compost for nutrients. Good drainage is essential for Smooth Blue Aster to prevent waterlogging, which leads to root rot and fungal issues.
How Often Should You Fertilize a Smooth Blue Aster?
Feed Smooth Blue Aster every 6 months during the growing season (spring and summer) with a balanced fertilizer diluted to the strength on the label.
Pause feeding in autumn and winter, when growth slows, and never fertilize dry soil — water first.
Fertilizing
Every 6 months
During the growing season
The PlantoScan app can remind you when to water and when to fertilize each plant.
How Do You Repot a Smooth Blue Aster?
Repot every 2-3 years in early spring. Choose a pot one size larger than the current container, and ensure it has drainage holes to allow excess water to escape.
How Do You Propagate a Smooth Blue Aster?
Smooth Blue Aster can be propagated through division, stem cuttings. Similar propagation techniques also apply to pineywoods aster plant care, which shares the same genus.
Is the Smooth Blue Aster Toxic to Pets and Children?
Pet safety not verified
The ASPCA does not list Smooth Blue Aster, so we can't confirm whether it is safe for cats and dogs. Keep pets from chewing it as a precaution.
This is a general caution, not veterinary or medical advice. If your pet ate a plant, contact your vet or animal poison control.
See all plants toxic to cats and plants toxic to dogs.
What Pests and Diseases Affect the Smooth Blue Aster?
Smooth Blue Aster is susceptible to aphids, spider mites, powdery mildew. Inspect the foliage regularly, especially along leaf undersides and stems. Treat infestations promptly with insecticidal soap or neem oil to prevent spread.
Yellow leaves, brown tips or drooping? See common plant problems and how to fix them.
What USDA Hardiness Zone Does the Smooth Blue Aster Need?
Smooth Blue Aster grows outdoors in USDA Zone 3a – 8b. It survives winters down to planting zone 3a. Smooth Blue Aster is native to Canada, the United States, and Coahuila (Mexico).
Hardiness Zone
Zone 3a – 8b
Keep exploring plants
Smooth Blue Aster is one of many species covered in the complete plant care and identification guide, which groups plants by genus, attribute, and popularity.
It belongs to the Symphyotrichum genus — compare its care with other Symphyotrichum species on PlantoScan.
Symphyotrichum is part of the Asteraceae plant family — browse all Asteraceae genera and species.
Smooth Blue Aster thrives in bright light and direct sun — see other bright-light plants.
More Symphyotrichum Species
Other Symphyotrichum species in PlantoScan's care catalogue share similar watering, light, and soil preferences:
Sources
- Scientific name & taxonomy: Symphyotrichum laeve (L.) Á.Löve & D.Löve, family Asteraceae (first published in Taxon 31: 359 (1982)) — World Flora Online record, IPNI name record.
- Pet toxicity: Pet safety not verified: the ASPCA does not list Smooth Blue Aster, so we can't confirm whether it is safe for cats and dogs. Checked against the ASPCA plant list; any other toxicity note on this page comes from PlantoScan's plant database.
- Photo: Kathleen Houlahan Chayer, CC0, Wikimedia Commons — original.
- Hardiness zone: USDA Zone 3a – 8b, estimated from the plant's typical growing conditions.
- Care values(watering, light, temperature, humidity, soil, fertilizing): PlantoScan's plant database, filtered by automatic plausibility checks — values that fail them are hidden. How we source and check plant data.
Spotted a mistake? Email info@upvision.media with the page link — we check and correct reported errors.
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