Alkali marsh aster
Symphyotrichum lanceolatum · 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
- August to October
- Adult size
- 24 to 35 inches tall
- Growth
- Fast
- Hardiness
- Very hardy (down to -4°F)
- Origin
- North America (Great Plains)
- Soil type
- Well-draining, tolerant
Care
Sunlight
Lance-leaved aster prefers full sun for generous flowering. It tolerates partial shade but produces fewer flowers. Plant it in an airy location to prevent fungal diseases.
Watering
Water regularly for the first few weeks after planting to establish the root system. Once established, lance-leaved aster tolerates relative drought thanks to its deep roots. Reduce watering in autumn.
Soil
Plant in well-draining soil, even if poor or chalky. Lance-leaved aster dreads winter waterlogging more than poor substrate. Improve heavy soil with sand or gravel.
Fertilizing
A moderate application of compost or balanced fertilizer in spring is sufficient. Too much nitrogen encourages foliage at the expense of flowers. No application needed on enriched soils.
Pruning and pinching
Pinch stems in early summer to branch out the plant and get more flowers. Remove spent flowers to extend blooming. Cut at ground level after frost to clean up the plant.
Diseases and pests
Aster can suffer from powdery mildew in overly humid conditions or spider mites during dry periods. Good air circulation reduces these risks. Few significant pests under normal conditions.
Did you know?
North American asters fascinated European botanists from the 17th century onward to the point that they called them "queens of autumn." Symphyotrichum lanceolatum, with its delicate small flowers, was a key element of flowering prairie, providing abundant nectar for butterflies in late season.
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.
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Tips generated and checked by Viridia — adapt them to your local climate.