Batten Blooms
PL. —Erigeron glaucusBotanical illustration — drop image
Erigeron glaucus

Seaside Daisy

SpringSummerFall
5a–9bHardiness zone
Peak bloom windowZone 6b · frost-offset weeks
Winter
Not in bloom
Spring
Peak bloom
Summer
Peak bloom
Fall
Not in bloom
Peak bloom
In bloom
Background

Erigeron glaucus is a low-growing perennial native to coastal bluffs and sandy beaches of California and Oregon. It produces lavender to purple ray flowers with yellow centers over an extended season and tolerates salt spray, sandy soils, and coastal wind better than most ornamentals.

Plants spread into a dense mat and become highly drought tolerant once established. Lean, well-drained or outright poor soil produces tighter, more upright growth; rich or consistently moist soil leads to floppy stems and increased disease pressure. Clumps turn woody at the base after two to three years and benefit from division or a hard cutback in early spring to maintain vigor. In zones below 7, a light mulch over the crown before first frost improves winter survival.

The long flowering period makes this species a consistent nectar source for native bees, butterflies, and syrphid flies. Its mat-forming habit also helps stabilize sandy slopes and suppress weeds along path edges in low-water or California-native plantings.

Good companions
California BuckwheatSea ThriftYarrowKinnikinnick
Care guide
SunFull sun to part shade
WaterLow
SoilWell-drained, sandy, lean
Spacing12–18 in
Height6–12 in
Zone5a – 9b
Native RegionCA, OR
Frost hardy
Seasonal tasks
spring
watchScout new growth for aphid colonies; dislodge with a firm water spray or apply insecticidal soap for heavy infestations.
cutCut woody stems back to 3–4 in in early spring before new growth emerges to rejuvenate the clump and tighten the mounding habit.
sowPlant nursery transplants or rooted divisions into well-drained soil once the risk of hard frost has passed.
summer
cutDivide overgrown or open-centered clumps in early fall in mild-winter climates; replant vigorous outer sections at original depth.
cutRemove faded stems regularly to extend the blooming period and prevent the plant from becoming straggly.
watchCheck for powdery mildew in humid or poorly ventilated spots; reduce overhead irrigation and thin congested growth.
fall
cutAfter first frost, trim plants to 3–4 in and apply a light mulch over the crown in zone 5–6 gardens.
Common problems

Powdery mildew

Symptoms

White or grey powdery coating on leaves — usually starting on older growth in humid conditions or when nights cool.

Treatment

Improve air circulation by thinning plants. Apply neem oil or potassium bicarbonate spray at first sign. Avoid overhead watering.

Aster Yellows

Symptoms

Deformed, greenish flowers, stunted growth, and yellowed foliage. Flower centers may produce tufts of leafy growth instead of normal petals.

Treatment

No cure. Remove and destroy infected plants immediately to stop spread. Control leafhoppers, which transmit the disease, and remove nearby weed hosts.

Fungal leaf spot

Symptoms

Brown or purplish spots on the leaves, often ringed with a yellow halo, that spread and merge in warm, humid, or wet weather; heavily spotted leaves yellow and drop early.

Treatment

Pick off spotted leaves and clear fallen debris to remove overwintering spores. Improve air circulation by thinning, and water at the base so foliage dries quickly. If it persists, apply a copper- or sulfur-based fungicide at the first sign.

Rust

Symptoms

Orange to brown raised pustules on the undersides of leaves, with yellow spotting on the upper surface. Heavy infections cause leaves to yellow and drop.

Treatment

Remove and destroy infected leaves. Avoid overhead watering and improve air circulation. Apply a sulfur or copper-based fungicide if it spreads. Clear plant debris in fall.