This document summarizes information about Coastal (Marsh) Gumplant, a creeping perennial native to coastal California. It has low, spreading stems that form a mat, green succulent leaves, and showy yellow flower heads in summer and fall. It is well-suited as a groundcover, tolerating sandy and poor soils near beaches. Coastal Gumplant requires full sun, attracts butterflies and provides habitat for birds and small mammals. It can be propagated from seed or divisions and is a sensible substitute for non-native groundcovers and asters.

1. Coastal (Marsh) Gumplant – Grindelia stricta var. platyphylla
(grin-DELL-ee-uh STRICT-uh plat-ee-FIE-luh)
Family: Asteraceae (Sunflower Family)
Native to: Coastal CA from coast of Santa Monica Mountains to central OR; native to tidal flats,
marshes, dunes and sandy sea bluffs in coastal shrubland.
creeping perennial
mature height: 1-2 ft.
mature width: 2-5 ft.
Low, mostly prostrate perennial/groundcover with woody stems at base.
Leaves are green
(sometimes with red edges), succulent, drought deciduous. Plant variable in appearance depending
on conditions. Often a spreading mat of clumped plantlets. Spreads via rhizomes. Fast growth.
Growth characteristics:
Blooms summer/fall (June to Sept). Flowers are typical for Gumplants: showy
yellow ‘sunflower’ heads with characteristic sticky white ‘gum’ on buds (Native Californians chewed
this as gum). Quite showy and decorative.
Blooms/fruits:
Uses in the garden: Probably best used as a groundcover and on slopes, alone or with other native
groundcovers. Does very well near beach and in sandy soils. Tolerates windy conditions.
Nice
with other native shrub species; decorative draped over a wall.
Probably fine in a large pot or
planter. Foliage fragrant when crushed. Good for firescaping if kept green.
Sensible substitute for: Non-native Asters, Chrysanthemums, non-native groundcovers.
Excellent butterfly nectar source in summer/fall; birds & small mammals eat the seeds,
use plant as shelter and nesting site.
Attracts:
Requirements:
Element
Sun
Soil
Water
Fertilizer
Other
Requirement
Full sun (coast) to part-shade (everywhere else)
Any well-drained; most clays are fine. pH : 5.0-7.5 or a little higher
In nature gets ocean spray – rinse with hose in summer, or plant where it gets
some sprinkler spray. Benefits from occasional summer water.
None; likes poor soils
Pretty indestructible. Will spread fairly quickly.
Cut back tall branches and spent
flower heads in fall. You can cut back severely in fall to rejuvenate.
Management:
Propagation: from seed: soak 24 hours in water first
by divisions, semi-softwood: yes, easy
Plant/seed sources (see list for source numbers): 1, 2, 3, 5, 10, 11, 13
2/16/11
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