Banksia 'Coastal Cushion' (Banksia spinulosa 'Coastal Cushion') is a hairpin banksia that spreads instead of standing upright. It holds at roughly 60cm tall and 2m across, and it carries full sized golden orange candles at knee height through the cooler months. On a sandy bank or an exposed front garden it works as groundcover and flowering shrub at once.
Why you'll love it
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Banksia flowers at ground level. The gold and orange brushes are as large as those on upright banksias, held where you actually see them.
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Food for birds in the cold months. Honeyeaters and wattlebirds work the candles through autumn and winter, and bees follow.
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Built for hard sites. Salt wind, drought, frost and poor sandy soil are all within its range.
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Wide cover from one plant. Spreading to 2m, it closes ground fast, so a slope needs fewer plants than you would expect.
Where it works best
Groundcover and mass planting. Plant 1.2m apart and the mounds knit into continuous cover over two to three seasons.
Coastal gardens. Salt laden wind does not burn the fine foliage, so it can sit in the front line of a beach house planting.
Slopes and retaining walls. The low spreading habit holds soil on a bank, and plants set above a wall spill over the edge to soften it.
Growing Banksia Coastal Cushion in Australia
Position and climate. Full sun gives the heaviest flowering; light shade is tolerated but the mound grows looser. It suits subtropical, warm temperate, cool temperate and mediterranean gardens, and is frost hardy once established. Wet tropical gardens are the exception.
Soil. Sandy or gravelly ground is ideal and poor soil is no problem, but drainage is not negotiable. On clay, mound the bed 30cm and open it with gypsum and coarse compost. Mulch with coarse bark, kept clear of the stems.
Water and feed. Water deeply once or twice a week through the first summer, then only in long dry spells. Feed with a low phosphorus native fertiliser in early spring and nothing else, because banksias are phosphorus sensitive and standard garden blends can kill them.
Pruning. Tip prune lightly once the candles finish to keep the mound dense. Do not cut into bare old wood, as it does not reliably reshoot.
What to expect when it arrives
It is grown in two sizes: tube stock and a 140mm pack of ten. Tubes are young single plants and the sensible choice for covering a bank, since they establish fast and cost far less per square metre. The pack of ten gives larger, already branching plants, enough for about 14 square metres at 1.2m spacing.
Plants travel upright and are delivered Australia wide, with delivery from $29.95. Expect little visible movement for the first month while roots move into the surrounding soil, then a spreading flush through the first warm season. Every plant is covered by our 30 day healthy plant guarantee.
Plant care guides and related reading
Common questions
How many plants do I need for a bank?
At 1.2m spacing, allow about seven plants for every ten square metres. Closer spacing closes the gaps a season sooner but costs more and makes early weeding awkward.
When does it flower?
Mostly through autumn and winter, often for months. The spent brushes dry into sculptural seed cones that many gardeners leave in place.
How quickly does it spread?
Expect close to a metre of width in the first two years in a sunny, well drained spot, and full cover by the third or fourth year. Growth is slower in shade or heavy soil.