Coleus canina, often called the “gorilla plant,” possesses a distinct, musky aroma that serves as its primary repellent mechanism. This strong scent is usually undetectable by humans unless the plant is brushed against or disturbed, but it is quite potent for many animals. The odor is believed to be particularly unpleasant to canines and felines, making it a popular choice for deterring neighborhood cats and dogs from garden beds.
Understanding the Repellent Properties
Gardeners often position these plants strategically around vegetable patches, flower borders, or near entry points to discourage common garden pests like rabbits, deer, and squirrels from foraging or digging. Placing them along the perimeter of a garden or around specific plants can maximize deterrence. While many gardeners report success, the plant’s effectiveness can vary and is not universally guaranteed for all animals or situations.
Growing and Caring for Your Gorilla Plant
Cultivating Coleus canina successfully begins with understanding its preferred growing conditions. This plant thrives in full sun to partial shade, needing at least six hours of direct sunlight daily for optimal growth and scent production. Too much shade can diminish its characteristic odor and lead to leggy growth.
The ideal soil is well-draining, moderately fertile, and has a slightly acidic to neutral pH (6.0-7.0). Amending heavy clay soils with organic matter improves drainage, as the plant dislikes soggy roots. Sandy soils benefit from added compost for water retention and nutrient availability.
Consistent moisture is important, but avoid waterlogging. Water thoroughly when the top inch or two of soil feels dry, allowing excess water to drain. Watering frequency depends on climate; plants in hotter, drier regions or containers need more frequent irrigation.
Coleus canina is typically hardy in USDA zones 9-10 as a perennial. In colder climates, it is often cultivated as an annual or brought indoors before the first frost. The plant prefers warm temperatures and does not tolerate freezing conditions.
While not a heavy feeder, a balanced liquid fertilizer during the active growing season supports robust foliage. Apply fertilizer at half the recommended strength every two to four weeks from spring through late summer. Over-fertilization can lead to excessive leafy growth at the expense of scent production, so moderation is advised.
Propagation and Maintenance
Multiplying Coleus canina is straightforward through stem cuttings. Select healthy, non-flowering stems 4-6 inches long, making a clean cut just below a leaf node. Remove lower leaves to expose at least two nodes.
Cuttings can be rooted in water or directly in a well-draining potting mix. If rooting in water, place the cut end in a glass, changing the water every few days until roots are visible (usually within 2-3 weeks). For soil rooting, insert cuttings into moist potting mix and keep the soil consistently damp in a warm, bright location.
Regular maintenance, particularly pruning, helps keep the plant bushy and vigorous. Pinching back the growing tips of young plants encourages branching and a denser habit, preventing legginess. This redirects the plant’s energy into producing more foliage, where repellent compounds are primarily located.
Removing spent flower stalks (deadheading) is also beneficial. This prevents the plant from expending energy on seed production, allowing it to focus resources on maintaining strong, fragrant foliage throughout the growing season.
Safety and Considerations
While Coleus canina is widely used as an animal deterrent, it is important to understand its potential effects. Ingestion by pets, particularly dogs and cats, can cause mild gastrointestinal upset, including vomiting or diarrhea. Although not considered highly toxic, monitor pets and consult a veterinarian if ingestion is suspected or symptoms persist.
For humans, the plant’s distinctive odor is usually only noticeable when the foliage is touched or disturbed. Most people do not find the scent unpleasant and may not detect it from a distance. The strong musky smell that deters animals is not typically an issue for human enjoyment of the garden.
It is worth reiterating that while many gardeners find Coleus canina effective, its repellent properties are not universally guaranteed. Individual animals may react differently to the scent, and some may not be deterred. It functions best as one component of a broader strategy for managing garden pests rather than a standalone solution.