Coleus is a tender perennial, often grown as an annual, cultivated primarily for its spectacularly vibrant foliage rather than its small flowers. The practice of pinching is strongly recommended to maintain the plant’s desired appearance. This maintenance task involves selectively removing growth tips to manage the plant’s shape and conserve its internal resources. Pinching interferes with the plant’s natural reproductive cycle, ensuring the focus remains on producing the colorful leaves that are the plant’s primary decorative feature.
Why Deadheading Is Essential for Coleus Health
Coleus plants are typically grown for their colorful, patterned leaves, so gardeners aim to maximize foliage production. When the plant begins to flower, it redirects significant metabolic energy away from leaf development and toward reproductive structures. This shift in resource allocation is detrimental to the plant’s ornamental value, as the foliage often becomes smaller and less intensely colored. Removing the developing flower spikes interrupts this process, forcing the plant to conserve energy for vegetative growth.
Flowering also triggers hormones that contribute to a growth habit known as “legginess.” This occurs when stems elongate rapidly with sparse leaf coverage, resulting in a spindly appearance. Pinching the growing tips removes apical dominance, which is the mechanism causing the main stem to grow most vigorously. This action encourages lateral buds lower down the stem to activate, causing the plant to branch out horizontally into a denser, bushier form with rich color saturation.
Identifying the Right Time to Prune
Pruning Coleus is not a single seasonal event but a continuous maintenance process throughout the active growing season. The most obvious cue is the emergence of the flower spike, which is a slender stalk often topped with small, pale blue or lavender blossoms. These spikes usually rise above the main canopy of leaves and should be removed as soon as they are spotted to prevent the energetic drain of seed production.
Beyond flowering, the plant itself provides visual signals that it needs attention. Look for stems that have become long and bare, indicating the onset of legginess. When a stem has four to six sets of leaves but is still growing upward without branching, it is an ideal candidate for pinching. Regularly checking the plant for these signs ensures the plant remains compact and full throughout the growing season.
Step-by-Step Guide to Pinching and Trimming
The process involves two techniques: pinching for soft, new growth and trimming for older, woodier stems. To pinch, simply use your thumb and forefinger to snap off the soft growth tip, including any flower spike, at the top of the stem. This technique is best for young plants and for removing flower buds before they fully develop.
For more mature plants or to reduce overall height, use sharp, clean shears for trimming. Make the cut just above a leaf node, which is the point where a set of leaves or a side shoot emerges. This placement is important because the dormant buds at the node will immediately activate, producing two new stems and ensuring a dense growth habit. To prevent the spread of plant diseases, sanitize your cutting tools with rubbing alcohol between plants.