Silverbush (Convolvulus cneorum)
Silverbush (Convolvulus cneorum) is a low-maintenance, drought-tolerant dwarf shrub prized for its silvery foliage and white trumpet flowers.
Complete Plant Information
Overview
The Silverbush, scientifically known as Convolvulus cneorum, offers striking textural contrast in the landscape, making it a standout choice for Mediterranean-style or drought-tolerant gardens. Its primary appeal lies in its dense, mounding habit and foliage covered in soft, silvery-gray hairs, providing year-round visual interest. Gardeners value this evergreen dwarf shrub for its ease of care and ability to thrive in sunny, lean conditions common in low-water landscapes.
This engaging plant produces masses of funnel-shaped white flowers, each featuring a desirable yellow throat, blooming profusely from early summer into August. Whether used as a permanent fixture in warmer climates or grown as a vibrant container annual further north, Convolvulus cneorum brings brightness through both leaf and flower. The low maintenance requirements ensure that this beautiful shrub remains a favorite for those seeking maximum impact with minimal effort.
Fast Facts
- Plant Family: Convolvulaceae
- Plant Type: Broadleaf evergreen
- Native Range: Northern Africa, southeastern Europe
- Hardiness Zones: USDA Zones 8-10
- Size at Maturity:
- Height: 1-2 ft
- Spread: 2-3 ft
- Bloom Time: June to August
- Bloom Description: White with yellow throat
- Sun Exposure: Full sun
- Water Needs: Dry to medium
- Maintenance Level: Low
How to Grow
Convolvulus cneorum prefers planting in full sun, which helps intensify the silvery color of its foliage. It establishes well in average, well-drained soils, though established plants display remarkable tolerance for dry soils once settled. While it thrives in medium moisture levels, excessive wetness, especially in winter, should be avoided. In extremely hot summer locations, offering protection from the most intense afternoon sun may be beneficial.
Maintenance for Silverbush is generally low. Water sparingly once the plant is established; drought tolerance is a key feature. Minimal pruning is usually required, mainly to maintain shape or remove any dead wood. If growing this plant as a non-hardy annual in northern regions, container plants can be successfully overwintered indoors by placing them in a sunny location.
Propagation can be achieved via cuttings, offering a great way to increase your stock of this attractive shrub. If starting from seed, sow outdoors about two weeks before the last spring frost date, or start indoors about 5 to 6 weeks prior to provide a head start for seasonal display.
Landscape Uses
The striking appearance of Convolvulus cneorum makes it extremely versatile for sunny garden applications. It is a popular container plant across all USDA zones, offering a silvery backdrop or accent among seasonal color displays. In its hardy zones, Silverbush functions beautifully as a low, informal border edging or as an attractive accent within rock gardens where drainage is naturally excellent.
Consider pairing the cool silver tones of the Silverbush with plants that offer contrasting dark foliage or warm colors, such as deep purple Heuchera or bright yellow yarrow (Achillea). Its compact, mounding habit prevents it from becoming unruly, ensuring it complements structure without overwhelming smaller plantings. Use it where its drought tolerance can be appreciated, such as along dry retaining walls or sparingly irrigated slopes.
Standout Features
Flower Qualities
- Showy
Noteworthy Characteristics
Convolvulus cneorum, commonly called silverbush or bush morning glory, is native to the Mediterranean region. It is a dense, mounding, evergreen dwarf shrub recognizable by its attractive silver-green leaves and its funnel-shaped white flowers that open from pink buds. The specific epithet, cneorum, indicates that the foliage is reminiscent of olive leaves, and the genus name refers to the Latin word convolvo, meaning to twine around.
Tolerances
- Drought
Potential Problems
Convolvulus cneorum generally exhibits remarkable resistance, posing no serious insect or disease problems when grown outdoors in its ideal climate. Growers transplanting or overwintering container specimens indoors should remain vigilant for common houseplant pests. Specifically, watch closely for infestations of aphids or tiny spider mites, especially as the indoor winter air quality tends to be drier, which favors mite development. Ensure good air circulation when brought inside to minimize fungal issues.
Frequently Asked Questions
What hardiness zones is Silverbush suitable for?
Convolvulus cneorum is reliably winter hardy in USDA Zones 8 through 10.
How large does Silverbush grow?
This dense, mounding shrub typically matures to a height between 1 and 2 feet, spreading 2 to 3 feet wide.
What sun exposure does Convolvulus cneorum need?
Full sun exposure is ideal for encouraging the best foliage color and bloom performance for this Mediterranean native.
When does Silverbush bloom?
The trumpet-shaped white flowers with yellow centers appear abundantly from June through August.
Conclusion
The evergreen foliage and low-maintenance nature of Silverbush (Convolvulus cneorum) make it an invaluable textural component for sunny landscapes, especially those prioritizing water conservation. Utilizing this drought-tolerant species in containers or perennial borders adds consistent silver glow and summer blooms. Ensure excellent drainage and appropriate hardiness zone selection to enjoy this beautiful shrub for years to come.
Companion Planting
Selecting companions for Silverbush involves prioritizing plants that share its love for full sun and dry to medium soil conditions. Succulents and hardy perennials that thrive in arid environments make excellent partners. Consider pairing Convolvulus cneorum with plants like Lavender (Lavandula), which offers complementary fragrance and texture, or Santolina, known for its fine, silvery foliage. The bright white blooms of Silverbush also contrast beautifully against the deep purples or blues of plants like Russian Sage (Perovskia atriplicifolia) when sited in a border setting.
Propagation Tips
The cultivation of Convolvulus cneorum can be extended by taking softwood cuttings, allowing gardeners to multiply preferred specimens easily. Cuttings should be taken during the active growing season, typically late spring or early summer, ensuring they are healthy and non-flowering terminal stems. Dip the base of the cutting in rooting hormone, if desired, and place them in a sterile, porous medium like a mix of peat and perlite in a warm, shaded environment. Maintaining consistent moisture—but never saturation—around the base of the cutting until root formation occurs is key to success before transplanting them into their final location as annuals or moving them to pots for overwintering.
