Pelargonium zonale
Pelargonium zonale
Zonal pelargonium
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Taxonomy
Family Geraniaceae · Genus Pelargonium
Description
Pelargonium zonale is the wild parent behind classic zonal geraniums—compact, sun-loving, and generous with blooms. Its rounded, banded leaves and clusters of pink to red flowers bring cheerful color to windowsills, patio pots, and sunny beds, especially in warm seasons.
Common Names
Zonal pelargoniumHorseshoe geraniumZonal geranium (species)Garden geranium (species)
Context
nativeRegion
South Africa (Western and Eastern Cape)
usdaZones
10–11 as a tender perennial; commonly grown as a warm-season annual elsewhere.
companionPlants
Lobelia, Verbena, Salvia, Dusty miller (Senecio cineraria), Sweet alyssum, Calibrachoa, Petunia, Lantana
culturalUses
Classic bedding and container plant for long seasonal color; window boxes and edging; lightly aromatic foliage; historically popular in Victorian gardens; key parent in modern zonal geranium breeding.
Care
Care Requirements
LightFull sun to bright light; 4–6+ hours of direct sun. In very hot climates, provide light afternoon shade.
WateringWater when the top 1–2 in (2.5–5 cm) of soil are dry. Keep evenly moist in active growth; reduce in winter. Never leave soil soggy.
SoilVery well-drained, airy mix (potting soil + perlite/pumice + coarse sand). pH 6.0–7.5.
FertilizerFeed every 2–4 weeks in spring–summer with a balanced or bloom fertilizer at half strength; little to none in winter.
HumidityAverage household humidity (30–50%) is ideal; ensure good airflow and avoid prolonged leaf wetness.
TemperatureBest at 60–75°F (15–24°C). Protect from frost; minimum 45–50°F (7–10°C).
Growth & Life Cycle
HabitUpright, bushy subshrub with semi-succulent stems and rounded, zoned leaves.
Mature Size12–36 in tall and 12–24 in wide (30–90 cm tall, 30–60 cm wide).
Growth RateFast in warm, bright conditions.
BloomingClusters of pink to red flowers from spring through fall; deadhead to extend blooming.
DormancySemi-dormant in cool, short days; growth slows markedly. Overwinter indoors in bright light or store cool and dry.
Propagation
MethodsStem cuttings, Seeds
DifficultyEasy
Best SeasonSpring is best; possible from late winter to late summer during active growth.
Maintenance & Notes
PruningPinch tips to encourage branching; remove spent flower heads; cut back by up to one-third in late winter or early spring.
RepottingRepot in spring when roots fill the pot. Prefers a snug container with sharp drainage; refresh potting mix annually.
Pests & DiseasesWatch for aphids, whiteflies, spider mites, mealybugs, and caterpillars. Diseases include botrytis, rust, bacterial blight, and root rot—avoid overcrowding and wet foliage.
ToxicityMildly toxic to cats and dogs (geraniol, linalool); may cause GI upset and skin irritation. Sap can irritate sensitive skin.
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