Pelargonium inquinans, often called the Scarlet Geranium, is a vibrant plant for gardens and indoor spaces. Native to South Africa, this evergreen perennial is characterized by its soft, woody stems, rounded green leaves, and clusters of scarlet flowers that can reach 3.5 inches across. These striking blooms appear from spring through summer. Its adaptability makes it a popular choice for both container gardening and as a border plant.
Essential Care Requirements
Light
Pelargonium inquinans thrives in bright, direct sunlight, ideally receiving at least six hours of light daily. For indoor cultivation, a bright location near a south-facing window is ideal. While full sun encourages the most abundant flowering and vibrant foliage, these plants can tolerate slightly less light, though blooms may be less prolific. If exposed to excessive afternoon sun, particularly in hot climates, the leaves can experience sunburn, so some afternoon shade can be beneficial. Yellowing leaves can indicate insufficient light, suggesting a need to move the plant to a brighter location.
Watering
Moderate watering is important for Pelargonium inquinans, as it prefers the soil to dry out partially between waterings. Overwatering is a common issue that can lead to root rot, evident if the soil remains soggy. To check soil moisture, insert your finger into the potting mix; if the top inch feels dry, it is time to water thoroughly until water drains from the bottom of the pot. Conversely, underwatering can also cause yellowing leaves, particularly at the edges and tips. During winter dormancy, watering should be significantly reduced, only providing enough to prevent the soil from completely drying out.
Soil Mix
A well-draining, loamy soil mix is ideal for Pelargonium inquinans. Good drainage is paramount to prevent waterlogging. A suitable potting mix can be created using garden soil, compost, and sand. For container-grown plants, a peat-free multipurpose compost or a soil-based compost works well. Incorporating perlite or vermiculite can further enhance drainage and aeration. The plant prefers a soil pH that is slightly acidic to neutral, typically ranging from 6.0 to 7.0.
Temperature and Humidity
Pelargonium inquinans prefers moderate temperatures and requires protection from frost. Optimal daytime temperatures typically range between 70-85°F (21-29°C), with nighttime temperatures between 55-65°F (13-18°C). Prolonged exposure to temperatures below 50°F (10°C) can cause cold damage, resulting in yellowing leaves, wilting, and stunted growth. The plant enjoys moderate humidity, and while overly dry air can lead to some leaf loss, it typically fares well in average home humidity levels around 40%. Misting the leaves is generally not recommended as it can encourage disease.
Fertilization
During the active growing season, Pelargonium inquinans benefits from regular fertilization. A balanced fertilizer with an N-P-K ratio such as 10-10-10 or a similar balanced liquid feed can be applied every two weeks. Once flowering begins, switching to a high-potassium fertilizer can encourage continuous and abundant blooms throughout the summer. Fertilizers with a higher nitrogen content should generally be avoided during the blooming phase, as they can promote leafy growth at the expense of flowers. During winter dormancy, when plant growth slows, fertilization should be reduced or stopped entirely. Always dilute liquid fertilizers to prevent root damage.
Pruning and Maintenance
Pruning
Regular pruning helps maintain the shape of Pelargonium inquinans and encourages bushier growth and more prolific flowering. Deadheading, which involves removing spent flowers, conserves energy for new blooms. Leggy growth, characterized by long, sparse stems, can be addressed by pinching back the tips of shoots. Significant pruning, such as cutting stems back by two-thirds, can be done in early spring before the main growing season, or in autumn to prepare for winter. When pruning, make clean cuts just above a leaf node, as this is where new growth will emerge.
Repotting
Pelargonium inquinans generally prefers to be somewhat pot-bound, which can encourage more blooms. However, plants will eventually outgrow their containers, showing signs like stunted growth or roots emerging from drainage holes. Repotting is typically needed every one to two years. The best time to repot is in spring, just before the active growing season begins. Choose a new pot that is only slightly larger than the current one, and ensure it has adequate drainage holes. When repotting, gently remove the plant, shake off excess old soil, and place it in the new pot with fresh, well-draining potting mix. Avoid fertilizing immediately after repotting to encourage root establishment in the new soil.
Troubleshooting Common Issues
Yellowing leaves are a frequent concern for Pelargonium inquinans owners. This can stem from overwatering, underwatering, insufficient light, or nutrient deficiencies, particularly nitrogen. Applying a balanced fertilizer can help correct nutrient imbalances.
Leggy growth, characterized by stretched stems, indicates insufficient light. Moving the plant to a brighter location and regular pruning can help.
A lack of blooms can be due to inadequate sunlight. Improper fertilization (too much nitrogen or too little potassium) can also inhibit flowering. High-potassium fertilizer during blooming stimulates flower production.
Common pests that may affect Pelargonium inquinans include aphids, spider mites, whiteflies, and thrips. These can cause distorted growth, yellowing foliage, or premature flower drop. Good air circulation can help prevent some pest issues. If pests are identified, general management often involves horticultural oils, insecticidal soaps, or manual removal.
Fungal diseases like botrytis blight (gray mold) and root rot are often associated with overwatering and poor air circulation. Removing affected plant parts and improving environmental conditions are important steps in managing these issues.