Plectranthus caninus, also known as the “Scaredy Cat Plant” or “Piss-off plant,” is an herbaceous plant belonging to the mint family, Lamiaceae. It originates from eastern Africa, South Africa, and India. This species typically grows as an annual or short-lived perennial, reaching heights of 0.5 to 1.5 feet. Its fleshy, light green, oval leaves are covered in small hairs, often forming a compact, spreading mat.
Understanding Its Unique Properties
Plectranthus caninus gains its reputation from a characteristic musky aroma, sometimes described as skunky or similar to dog urine, which is released when the leaves are brushed against or crushed. This strong scent is widely believed to act as a natural deterrent to various animals, including cats, dogs, rabbits, deer, and possums, without causing them harm. While anecdotal evidence supports its effectiveness in discouraging animals from certain garden areas, formal scientific studies on its repellent properties are limited.
Growing and Care Guide
Light
Plectranthus caninus thrives in locations receiving full sun to partial shade. Full sun intensifies its characteristic scent. Too much shade can lead to leggy growth, where stems stretch excessively in search of more light, making the plant appear sparse.
Watering
This plant prefers well-draining soil and benefits from allowing the soil to dry out between waterings. Overwatering can lead to issues such as root rot or fungal diseases. While established plants are drought-tolerant, consistent moisture during the growing season promotes vigorous growth. Adjust watering frequency seasonally, increasing it in warmer months and reducing it in winter.
Soil and Nutrients
Plectranthus caninus is adaptable to a wide range of soil conditions but performs best in well-draining soil. The plant tolerates a pH range from slightly acidic to neutral, ideally between 5.8 and 7.0. During its active growing period, from spring through fall, a light monthly application of a balanced liquid fertilizer is beneficial, especially for container-grown plants.
Temperature and Humidity
Plectranthus caninus prefers warm environments and shows sensitivity to cold temperatures, languishing below 55°F. Optimal growth occurs when evening temperatures are above 60°F and daytime temperatures are below 95°F. In colder climates, it is typically grown as an annual because it is not frost-tolerant, though in USDA hardiness zones 8 and 9, it may survive winter with sufficient mulching. The plant does not have specific humidity requirements and generally thrives in relatively arid conditions.
Pruning
Regular pruning encourages a bushier growth habit and prevents the plant from becoming leggy. Pinching back the growing tips directs the plant’s energy into developing more foliage and branches rather than flowering. Removing pale blue to violet flower spikes also helps maintain the plant’s vigor and can enhance the scent of its leaves. Pruning can be done throughout the growing season to maintain the desired size and shape.
Propagation Methods
Propagating Plectranthus caninus is straightforward, typically done through stem cuttings. Take 3 to 5-inch cuttings, ensuring each has at least one or two leaf nodes, and remove leaves from the bottom third. Root cuttings in water (changing water every few days) or a consistently damp, well-draining potting mix. Roots usually develop within a few weeks. Propagation can be done anytime during the growing season, with early spring or late winter suitable for starting new plants indoors.
Safety and Considerations
Plectranthus caninus is generally considered non-toxic to most pets and humans. Some individuals with sensitive skin may experience mild irritation when handling the plant, so wearing gloves is advisable. The plant is relatively resilient to pests and diseases. However, gardeners should monitor for common issues such as aphids, mealybugs, spider mites, slugs, and snails. Fungal diseases like leaf spot and root rot can occur, particularly if the plant is overwatered or grown in poorly draining soil.