Alkali marsh aster
Symphyotrichum pilosum · Asteraceae
The gardener's calendar
Ideal time to plant alkali marsh aster: set it out when the soil is neither frozen nor waterlogged, and water generously as it establishes.
ID card
- Foliage
- Deciduous
- Flowering
- Fall (September to November)
- Adult size
- 24 to 40 inches tall
- Growth
- Fast
- Hardiness
- Very hardy (down to -4°F)
- Origin
- North America
- Soil type
- Well-drained, moderately fertile soil
Care
Watering
Water regularly during the growing season, especially during prolonged dry spells. Once established, hairy aster tolerates drought well and requires only moderate watering. Avoid excess moisture, which promotes fungal diseases.
Light Exposure
Plant hairy aster in full sun (at least 6 hours per day) for generous flowering. It also accepts partial shade, but flower production will be reduced and the plant may become slightly etiolated.
Pruning and Cutting
Prune stems in late winter or early spring before growth resumes. To encourage denser branching and more flowers, you can pinch back the tips before flowering. Cut back faded stems after blooming for aesthetic purposes.
Fertilizing
A balanced fertilizer application in spring is usually sufficient. Avoid excess nitrogen, which promotes foliage at the expense of flowering. Light compost applied at the base early in the season naturally enriches the soil.
Soil
Hairy aster prefers well-drained and slightly dry soil. Incorporate sand or coarse materials if your soil is too compact or clay-based. Soil that is too rich in organic matter can reduce hardiness and promote diseases.
Diseases and Pests
This plant is generally robust. Watch for powdery mildew in warm, humid weather: good spacing between plants and adequate air circulation prevent the problem. Pests are rare; monitoring for spider mites during prolonged drought is usually sufficient.
Did you know?
Hairy aster gets its nickname from the fine glandular down that covers its stems and leaves, particularly visible in raking light. Once widely hybridized, this North American aster served as a parent to many garden varieties, including some of the finest for fall bouquets.
Where to buy it
Plant in spring or early autumn, avoiding spells of intense heat. Pick a plant with healthy foliage and roots that are not exposed. Best time: March, April, May, September.
Add this plant to my garden →Plants from the same family
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Tips generated and checked by Viridia — adapt them to your local climate.