Silverbush

Silverbush (Convolvulus cneorum) is the silver mound that holds a sunny garden together. It forms a tight dome about 600mm tall and 1m wide, clothed in silky foliage that reads almost metallic in strong light, and from spring it opens white trumpet flowers across the whole surface. It is frost hardy, drought tolerant and salt tolerant, a rare combination in a plant this refined.

Why you'll love it

• Silver foliage all year. The silky leaves carry the plant every day of the year, not just through a short flowering window.
• White flowers from spring. Clean white trumpet flowers open over the mound, and bees and butterflies work them steadily.
• Tough where it counts. Frost hardy, drought tolerant, salt tolerant and untroubled by poor soil. Very few plants tick all four.
• It keeps its shape. A naturally dense dome at roughly 600mm by 1m, with no staking and no annual cutting back.

Where it works best

Borders and mass planting. Plant 70cm apart for a silver mass planting. At that spacing the domes meet in the second season and read as one continuous drift.

Coastal gardens. Salt tolerance and a low wind resistant profile make it one of the better choices for a front garden within reach of the beach.

Rockeries and pots. Sharp drainage is what it wants, so a gravel garden or a rockery suits perfectly. In a pot use a free draining mix and a container at least 400mm wide.

Growing Silverbush in Australia

Position and climate. Full sun, with air moving through the plant. Shade costs you the silver and opens the mound out. It suits Mediterranean, warm temperate, cool temperate and arid to semi arid gardens, and handles genuine frost. It is not a plant for humid subtropical or tropical gardens.

Soil. Sharp drainage above everything else. Sandy, gravelly and rocky soils are ideal, and poor ground is fine. On clay, plant high on a raised mound with coarse grit through the backfill.

Water and feed. Deep soak weekly through the first summer, then almost nothing beyond a drink in an extended dry spell. Rich soil is actively unhelpful: it produces soft green growth at the expense of the silver.

Pruning. Trim lightly after the main spring flush, taking no more than the outer third. Do not cut into old bare wood, because it reshoots poorly and can leave a permanent hole in the dome.

What to expect when it arrives

Silverbush is grown in three sizes. Tube stock is young and small, the value choice when you need numbers for a border or a mass planting. The 140mm pots, sold in packs of ten, and the 200mm pots, sold in packs of six, give stronger plants and roughly the quantities a 70cm spacing calls for.

Plants are packed to travel upright, and a little foliage dulling in the box lifts within a fortnight. Water in well, keep the water up through the first summer only, and expect a full dome by the second season. Plants are delivered Australia wide, with delivery from $29.95 and a minimum order of $300 before delivery. Every plant is covered by our 30 day healthy plant guarantee.

Plant care guides and related reading

• Browse more coastal and salt tolerant plants
• Compare options across our drought tolerant range
• See what else suits a sweep of one plant in mass planting plants
• Read about planning a coastal feature garden

Common questions

How far apart should I plant it?

Seventy centimetres apart for a mass planting or a border run. That matches the 1m mature width closely enough for the domes to meet in the second season.

Why has my plant died in the middle?

Almost always drainage or humidity. Silverbush needs soil that dries out between drinks, and it struggles through humid summers. Raise the bed and cut back on water.

Can I prune it hard to reshape it?

No. Take only the outer third after flowering. It reshoots badly from old bare wood, so a hard cut back usually leaves a gap that never closes.