Symphyotrichum, Genus, divaricatum, Species,
- Genus & species
southern annual saltmarsh aster
South-central and southeastern United States
SunFull Sun – Part Shade
WaterMedium
Overview
Symphyotrichum divaricatum, the southern annual saltmarsh aster, is a slender annual in the Asteraceae growing 8-32 inches (20-80 cm) tall and 6-18 inches (15-45 cm) wide, with wiry, widely branching stems that often sprawl. The narrow, linear to lance-shaped leaves are 1-3 inches (2.5-8 cm) long and reduce in size up the stem. From summer into autumn the branched stems carry many small flower heads, each 0.4-0.6 inch (10-15 mm) across with white to pale lilac rays around a small yellow disc that ages reddish. As an annual, it germinates in spring, flowers and seeds heavily through the season, then dies with frost, persisting only by reseeding. It grows on moist to seasonally wet, often saline or disturbed ground, including marsh edges, ditches, pond margins, floodplains, and roadsides. The wiry, much-branched habit and tiny flowers give it a weedy look, and it self-sows freely where soil stays open and damp.
Native Range
Native to the south-central and southeastern United States, especially Texas and the Gulf Coast, extending through the southern Great Plains and Mississippi valley. It grows on moist to seasonally wet, often saline or alkaline ground such as marsh edges, ditches, pond margins, floodplains, and disturbed roadsides.Suggested Uses
Used in native plantings, rain gardens, pond and marsh edges, and naturalised wet meadows, sown or self-seeded in open, moist ground and spaced about 10 inches (25 cm) apart. It suits informal, damp, or saline areas where its reseeding is acceptable. The weedy habit and small flowers make it poorly suited to formal beds or dry sites.How to Identify
Appearance
Size & Dimensions
Height8" - 2'8"
Width/Spread6" - 1'6"
Bloom Information
Detailed Descriptions
Flower Description
white to pale lilac rays with yellow discFoliage Description
greenGrowing Conditions
Sun Requirements
Requires 6-12 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight
Water & Climate
Water Needs
Care & Maintenance
Care Guide
Grows in full sun to light shade on moist to seasonally wet soils, including clay, silt, and saline or alkaline ground, at a pH around 6.0-8.0. As a warm-season annual it germinates in spring, needs steady moisture through the growing season, and tolerates brief flooding and salt. It needs no fertiliser on most sites and self-sows readily where soil stays bare and damp. Seedlings can be thinned to limit crowding. The plant completes its life cycle in one season and does not overwinter.Pruning
Requires no pruning as a short-lived annual. Sprawling stems can be trimmed to keep plants within bounds, and spent plants are pulled once seed has set. Clearing plants before seed drop limits self-sowing the following year.Toxicity
Non-toxicPlanting Guide
Planting Methods & Timing
Planting Method
direct sow
Direct Sow Timing
Sow in spring after frost on moist, open soil; seed germinates with warmth.
Days to Maturity
60–100 days
Plant Spacing
10 inches
