Silverbush Care (Convolvulus cneorum)

This sun-loving shrub needs strong light to keep its compact shape and silvery leaves dense.

• Provide 6–8 hours of direct sun daily; morning and midday sun are ideal, with light afternoon shade in very hot regions to prevent leaf scorch.
• It tolerates light partial shade (around 3–4 hours direct sun), but flowering decreases and growth becomes looser if light is reduced further.
• In winter, ensure an open, unshaded position so Silverbush receives low-angle sun and avoids prolonged damp, gloomy conditions.

This drought-tolerant shrub prefers infrequent, deep watering and fast-draining soil.

• Outdoors in the ground, water only when the top 3–5 cm of soil are completely dry; in summer heat, this may be every 7–14 days depending on soil and rainfall.
• Use sharply draining, sandy or gritty soil so Convolvulus cneorum does not sit in water, which leads to root rot and yellowing leaves.
• Reduce watering in cool seasons, watching for wilting or crisp leaf edges as signs of underwatering and blackened, mushy stems as signs of overwatering.

This Mediterranean shrub prefers warm, dry conditions and is sensitive to prolonged cold and frost.

• Aim for average growing temperatures of 65–80°F (18–27°C), which support steady growth and flowering during the main season.
• It tolerates brief dips to about 20–25°F (-6 to -4°C) once established, but foliage may burn; young plants are less hardy and need protection from hard frost.
• In hot climates, it handles 90–100°F (32–38°C) if soil drains well and roots stay aerated, but combine heat with some afternoon shade and low humidity stress.

This species prefers dry, airy conditions and usually does not need special humidity management.

• Target 30–50% relative humidity, similar to most heated indoor rooms or sheltered outdoor spots.
• Tolerates dry air well; problems appear more from excess moisture than from low humidity.
• If leaves yellow from the base or feel consistently damp, reduce ambient moisture and improve air circulation rather than trying to increase humidity.

This shrub needs very free-draining, mineral soil to avoid root rot and maintain compact growth.

• Use a sandy or gravelly mix with low to moderate organic matter to mimic the rocky habitats of Convolvulus cneorum.
• Aim for pH 6.5–8.0; slightly alkaline conditions from added lime or crushed limestone are acceptable.
• Combine 50–60% coarse sand or grit with 20–30% loam and 10–20% compost to balance drainage and nutrient supply.
• Avoid heavy clay, waterlogged spots, or peat-heavy mixes; improve existing soil by incorporating sharp sand and fine gravel for better aeration.

This species is well suited to container growing in sunny, well-drained positions.

• Choose a wide, shallow pot to accommodate its fibrous root system and spreading top growth without holding excess moisture.
• Use a heavy terracotta or stone container in windy locations to stabilize the low, mounding form.
• Elevate the pot on feet or spacers so drainage holes stay clear and runoff water does not pool under the container.

Convolvulus cneorum benefits from modest feeding in containers but needs little in lean, well-drained garden soil.

• Use a balanced slow-release fertilizer or light compost top-dressing at the start of spring growth.
• Feed once more in midsummer for potted plants; in the ground, one spring feeding is usually enough.
• Apply at 1/2 strength compared with label rates to avoid soft, leggy growth and salt buildup.
• Stop feeding in late summer so Silverbush can harden growth before cooler weather.

Pruning Convolvulus cneorum keeps the mound compact and supports flowering.

• Best time is right after the main spring flowering flush, avoiding hard cuts in late fall or winter.
• Remove dead, damaged, or crossing stems with clean hand pruners to reduce disease entry points.
• Lightly trim back spent flower stems to maintain a rounded, dense shape and encourage new shoots.
• Do not cut into very old, woody stems; focus on younger growth that still carries foliage.

This shrub is often grown in the ground, but container-grown plants or young stock benefit from careful transplanting.

• Plan transplanting or repotting for early spring, just as new growth starts and frost risk has passed.
• Look for roots circling the pot drainage holes, soil drying very fast, or slowed growth as signs to move up 1 pot size.
• Gently tease apart circling roots and set the plant at the same soil level in sharply drained, gritty mix.
• Water thoroughly, then keep slightly on the dry side for 1–2 weeks to limit root stress and rot risk.

Convolvulus cneorum is commonly propagated from semi-ripe cuttings rather than seed to maintain plant quality.

• Take 7–10 cm semi-ripe cuttings in late summer, choosing non-flowering shoots.
• Remove lower leaves, dip the base in rooting hormone, and insert into a free-draining sandy mix.
• Provide bright, indirect light, gentle warmth around 68–72°F, and high humidity while avoiding waterlogged media.
• Seed can be sown in spring in gritty soil, but germination is slow and offspring variable.

This Mediterranean shrub is moderately hardy but can suffer in prolonged freezing, wet conditions.

• In-ground plants in mild climates tolerate light frost if soil drains freely and does not stay saturated.
• Apply a thin, gritty mulch around the root zone in late fall, keeping it away from the woody crown.
• In colder regions, grow Convolvulus cneorum in containers and move it to a cool, bright, frost-free place for winter.