Aster spp. Aster

Edward F. Gilman, Ryan W. Klein, and Gail Hansen


Introduction

Asters produce large clusters of flowers in white, purple, lavender, pink, and red. The plants tolerate poor soil and dryness but bloom poorly in dry soil. They grow two to five feet tall and are spaced 15 inches apart. They multiply rapidly so may need frequent division. Tall varieties need staking or grow the shorter varieties. For best bloom, thin out shoots from large clumps. Asters grow best in full sun or light shade.

Full form - Aster spp.: Aster
Figure 1. Full form - Aster spp.: Aster
Credit: Edward Gilman, UF/IFAS

 

Flower - Aster spp.: Aster
Figure 2. Flower - Aster spp.: Aster
Credit: Edward Gilman, UF/IFAS

General Information

Scientific name: Aster spp.

Pronunciation: ASS-ter species

Common name(s): aster

Family: Asteraceae

Plant type: herbaceous

USDA hardiness zones: 4B through 9A (Figure 3)

Planting month for zone 7: year round

Planting month for zone 8: year round

Planting month for zone 9: year round

Planting month for zone 10 and 11: year round

Origin: native to Florida

Invasive potential: not known to be invasive

Uses: mass planting; edging; attracts butterflies; cut flowers

Availability: somewhat available, may have to go out of the region to find the plant

Shaded area represents potential planting range.
Figure 3. Shaded area represents potential planting range.
Credit: undefined

Description

Height: 1 to 3 feet

Spread: 2 to 4 feet

Plant habit: upright

Plant density: symmetrical habit with a regular (or smooth) outline and individuals having more or less identical forms

Growth rate: fast

Texture: fine

Foliage

Leaf arrangement: alternate

Leaf type: simple

Leaf margin: entire

Leaf shape: lanceolate

Leaf venation: none, or difficult to see

Leaf type and persistence: deciduous

Leaf blade length: 2 to 4 inches

Leaf color: green

Fall color: no fall color change

Fall characteristic: not showy

Flower

Flower color: lavender; white; pink; red; purple

Flower characteristic: summer flowering; fall flowering

Fruit

Fruit shape: unknown

Fruit length: unknown

Fruit cover: unknown

Fruit color: white

Fruit characteristic: inconspicuous and not showy

Trunk and Branches

Trunk/bark/branches: typically multi-trunked or clumping stems

Current year stem/twig color: green

Current year stem/twig thickness: thin

Culture

Light requirement: plant grows in full sun

Soil tolerances: acidic; slightly alkaline; sand; loam; clay

Drought tolerance: moderate

Soil salt tolerances: unknown

Plant spacing: 18 to 24 inches

Other

Roots: not applicable

Winter interest: no special winter interest

Outstanding plant: not particularly outstanding

Pest resistance: long-term health usually not affected by pests

Use and Management

Aster is grown from seed or division. Division is done in October or early spring when flowering deteriorates. The seed germinates in 15 days indoors or 20 to 30 days outdoors.

Pests and Diseases

Aphids feed on lower leaf surfaces and flower stems.

Japanese beetles feed on aster.

Leaf spot fungi cause spots of various types on the leaves. The spotting may be worse in rainy seasons.

Downy mildew causes a downy mold on the lower leaf surfaces but is not important on aster.

Powdery mildew develops on the lower parts of crowded plants in late season. Symptoms are a whitish coating on the leaves.

Bacterial crown gall causes the formation of rough, rounded galls. Avoid infested soil and destroy infected plants.

Verticillium wilt occasionally kills plants.