How to Grow Silver Waves
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Silver Waves
Cotyledon undulata
shrubCotyledon undulata is a drought-tolerant succulent shrub native to South Africa, prized for its silvery-gray, wavy-edged leaves and distinctive tubular orange-red flowers. This compact plant grows 12-18 inches tall and wide, making it excellent for containers, rock gardens, and xeriscapes. It's a low-maintenance ornamental that thrives in warm, dry conditions.
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Example Silver Waves timeline · Pittsburgh, PA (Zone 6b)
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Plant Silver Waves
Around Apr 17Near Pittsburgh's average last spring frost.
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Tend & protect
Late spring–summerWatering, feeding, and pest-watch reminders.
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Harvest Silver Waves
Around Aug 15≈ 120 days after planting
Sample dates for Pittsburgh, PA. Sign up to get exact Silver Waves dates for your own zip code.
Growing Conditions
Soil
Growing Zones
Find your zone →Thrives in zones 9b-11; can be grown in containers indoors in cooler zones
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Propagation
2-3 weeksStem cuttings or leaves are allowed to callus and root in dry conditions. Tiny white roots emerge from the base.
Let cuttings air-dry 3-5 days before planting. Keep soil barely moist until roots form (2-3 weeks). Protect from full sun initially.
Establishment
4-6 weeksNew growth appears as small leaves emerge from the base of cuttings. The plant gradually develops its characteristic silvery foliage.
Gradually increase light exposure. Water sparingly as the plant establishes. Avoid fertilizing young plants.
Vegetative Growth
8-12 weeksThe plant develops its full form with densely packed, wavy-edged silvery leaves. Branching increases and the plant becomes fuller.
Water moderately during warm months. Prune lightly to encourage bushier growth. Apply dilute succulent fertilizer monthly if desired.
Flowering
4-8 weeksDistinctive orange-red to coral tubular flowers appear at branch tips, typically in late spring to early summer. Flowers attract hummingbirds.
Continue watering during flowering but reduce frequency. Deadhead spent flowers to encourage more blooms. Provide full sun for best flowering.
Dormancy/Rest
12-16 weeksGrowth slows significantly in fall and winter. The plant enters a resting phase with minimal foliage change.
Drastically reduce watering—water only if leaves show signs of shriveling. No fertilizer needed. Protect from temperatures below 40°F.
Companion Planting
Plan your garden →Plant with:
Avoid planting near:
Common Pests
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Remove with rubbing alcohol on a cotton swab; spray with neem oil if infestation is severe. Isolate affected plants.
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Scrape off by hand; treat with horticultural oil or insecticidal soap. Repeat applications may be needed.
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Increase humidity slightly; spray with water or neem oil. Remove heavily infested leaves.
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Repot into fresh, dry soil; trim away blackened roots. Reduce watering frequency and improve drainage. May require fungicide in severe cases.
Uses
Xeriscape & Container Garden Display
OrnamentalCotyledon undulata is ideal for drought-tolerant landscapes, container gardens, and succulent arrangements. Its silvery foliage and striking coral flowers provide year-round visual interest in rock gardens and Mediterranean-style plantings. [source]
Hummingbird and Pollinator Attraction
WildlifeThe tubular orange-red flowers are highly attractive to hummingbirds and bees, making this plant valuable for gardens designed to support pollinators and wildlife. [source]
Dried Flower Arrangements
CraftThe coral flowers can be harvested and dried for long-lasting floral arrangements and craft projects, retaining their color well when properly dried. [source]
Low-Maintenance Indoor Houseplant
HouseholdIn cooler climates, Cotyledon undulata can be grown indoors on a sunny windowsill or under grow lights, requiring minimal watering and maintenance. [source]
Traditional South African Ethnobotany
MedicinalIn traditional South African medicine, Cotyledon species have been used in herbal remedies, though scientific validation is limited and ingestion is not recommended without expert guidance. [source]
This is not medical advice. LizPlants is not a medical resource. Always consult a qualified healthcare professional before using plants medicinally.
Harvest Tips
Cotyledon undulata is not harvested for food or commercial purposes. For propagation, take stem cuttings (2-4 inches) in spring/summer and allow to dry before planting. Leaf cuttings can also be propagated. Collect flowers for dried arrangements.
Fun Facts
- 🌱 Cotyledon undulata is sometimes called 'Silver Waves' because of its distinctive wavy, silvery-gray leaves that almost appear to ripple.
- 🌱 The plant's thick, waxy leaves are an adaptation to arid South African climates, storing water to survive extended droughts—a trait that makes it nearly impossible to overwater if soil drains well.
- 🌱 The tubular orange-red flowers were traditionally used by South African indigenous peoples and have become increasingly popular in contemporary succulent and container gardening.
Gardening Terms
New to gardening? Learn about terms used in this guide:
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