Strand (Island) Wallflower is a perennial or sub-shrub native to coastal Southern California and the Channel Islands. It grows 1-3 feet tall with gray-green, linear leaves and produces conspicuous bright yellow flowers in spring. The fruit is a long pod that splits open to reveal many tiny seeds. It requires full sun, well-drained soil, and low water needs, making it suitable for gardens, along walls, and to stabilize dunes or dry slopes. Propagation can be done from seed or cuttings in summer or fall.

1. Strand (Island) Wallflower – Erysimum insulare spp. suffrutescens
(air-ISS-i-mum in-soo-LAIR-ee suff-roo-TESS-sens)
Family: Brassicaceae (Mustard Family)
Native to: Southern California (Morro Bay to Los Angeles Co; Channel Islands). Grows on sand
dunes, coastal strand/prairie and in coastal sage scrub.
herbaceous perennial
mature height: 1-3 ft mature width: 1-2 ft
Small perennial or sub-shrub with erect or slightly curved stems. Leaves are gray-green, linear and
stress-deciduous in summer (dies back to ground if given no water).
Growth characteristics:
Blooms/fruits: Conspicuous bright yellow flowers in spring. Flowers are mostly at the top of the
plant.
Very showy when massed.
Fruit a long pod that splits open revealing many tiny seeds.
Uses in the garden: Cottage gardens, mixed beds (formal or informal), rock gardens, along walls,
natural plant gardens, to stabilize dunes or dry slopes.
Sensible substitute for: non-native Wallflowers (Erysimum cheiri); Dyer’s Woad (Isatis tinctoria)
Attracts: butterflies – especially Skippers
Requirements:
Element
Sun
Soil
Water
Fertilizer
Other
Requirement
Full sun
Well-drained sandy or gritty soil is best
Low needs; can survive no water in summer – but leaves will drop
None needed – thrives in nutrient poor soil
Does fine under maritime conditions
Management: Little needed. Cut back dead stems. Will spread with water. Short-lived, but often
will reseed naturally.
Propagation: from seed: collect seedpods when nearly dry. Dry in paper bags – they will split
open. Plant out in bed or pots in early fall or spring. By cuttings : in summer/early fall.
Plant/seed sources (see list for source numbers): 1, 2, 7, 8, 10, 11
11/29/10
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