Silverthorn
Also known as
Thorny Elaeagnus, Elaeagnus, Oleaster, Spiny Oleaster
Keep this plant’s care guide close at hand.
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Elaeagnus pungens, commonly called silverthorn, is a vigorous, evergreen shrub prized for its toughness and adaptability. It forms dense, arching, often spiny branches and reaches 8–15 feet (2.5–4.5 m) tall and wide, making it an excellent screen or windbreak. Leaves are leathery, dark green above and silvery-brown speckled beneath, reflecting light and resisting salt and wind burn. In autumn, small tubular white flowers appear, intensely fragrant and nectar-rich for late-season pollinators. These are followed by edible, speckled red fruits in late winter to spring. A nitrogen-fixer via root nodules (Frankia), it performs in poor soils and coastal conditions, tolerating drought, heat, and urban pollution. It accepts hard pruning and can be trained as a hedge or informal shrub. While highly useful, it may naturalize and become invasive in some regions; prevent spread by managing fruit and seedlings. Variegated cultivars offer additional ornamental interest, though they benefit from more sun for best color.
Taxonomy
Properties & Requirements
How to care for Silverthorn
Water
Water deeply and infrequently, prioritizing root establishment the first year. Provide weekly watering during the first growing season (about 1–1.5 inches/25–38 mm), especially in heat or sandy soils. Once established, silverthorn is drought tolerant and typically needs water only during prolonged dry spells. Always allow the top several inches of soil to dry between waterings; avoid persistently soggy conditions. Container-grown plants require more frequent checks—water when the top 1–2 inches are dry and ensure excellent drainage.
Light
Full sun to partial shade suits Elaeagnus pungens. Aim for at least 4–6 hours of direct sun for dense growth, abundant flowers, and best fruit set. Variegated cultivars color best with more sun but may appreciate light afternoon shade in very hot climates to prevent leaf scorch. Plants tolerate bright shade, though growth may become looser and flowering reduced. Avoid deep, sunless shade for hedging purposes.
Nutrients
As a nitrogen-fixing shrub, Elaeagnus pungens needs minimal feeding. In average soils, top-dress annually in early spring with 1–2 inches (2.5–5 cm) of compost or well-rotted leaf mold to boost organic matter and micronutrients. If growth appears weak in poor or sandy sites, apply a light rate of balanced, slow-release fertilizer (e.g., 8-8-8 or 10-10-10). Avoid high-nitrogen lawn fertilizers and late-summer applications that stimulate tender growth before winter. Maintain even soil fertility rather than pushing rapid growth.
Temperature
Hardy in USDA Zones 6–9, silverthorn tolerates winter lows around -10 to 0°F (-23 to -18°C) and thrives in hot summers. It withstands wind, salt spray, and urban heat. In colder zones, site it with wind protection to reduce leaf scorch and desiccation, especially on exposed sites. Avoid waterlogged soils in winter. In very hot inland climates, provide mulch and occasional deep irrigation during heat waves to limit stress.
