Nasturtiums are popular, easy-to-grow plants known for their vibrant, edible flowers and distinctive, rounded leaves. They thrive in various garden settings, from containers to ground covers, offering both ornamental beauty and culinary uses. Pruning nasturtiums is a straightforward practice that helps maintain their health and appearance throughout the growing season.
Why Prune Nasturtiums
Pruning nasturtiums offers several benefits for the plant’s health and your garden’s aesthetic. Removing spent flowers, a process known as deadheading, redirects the plant’s energy from seed production to creating more blooms, encouraging continuous flowering.
Pruning also encourages bushier growth, preventing the plant from becoming leggy or overgrown. Leggy nasturtiums have long, spindly stems with fewer leaves and flowers, which can make the plant look untidy. Trimming back overgrown stems helps maintain a compact, shapely form, improving air circulation within the plant and reducing the risk of disease. Managing their spread is particularly useful for vining varieties that can quickly take over garden spaces or shade out other plants.
Beyond aesthetic and health benefits, pruning facilitates the harvesting of nasturtium leaves, flowers, and seeds. Regularly picking leaves and flowers for culinary use, such as in salads or as garnishes, essentially acts as a form of light pruning, promoting new growth and continued production.
When to Prune Nasturtiums
Optimal pruning can begin in early spring, encouraging vigorous growth as the plant emerges. Pinching back young plants early in their growth cycle helps promote branching and a bushier form from the start.
Throughout the growing season, regular deadheading is recommended to encourage continuous blooming. For trailing varieties prone to becoming leggy, mid-summer or late-summer pruning is often necessary to stimulate new growth and blooms and maintain their shape. As annuals, nasturtiums’ pruning focuses on season-long maintenance.
How to Prune Nasturtiums
Always use clean, sharp tools, such as pruning shears or scissors, to make precise cuts and prevent the introduction of diseases. Disinfecting tools with a 10% bleach solution before and after use is a good practice.
For deadheading, locate spent or faded flowers. Pinch or cut the stem directly behind the dead bloom, just above a set of healthy leaves or a new bud. This prevents the plant from expending energy on seed production and encourages new flower development.
Pinching is ideal for young plants or for promoting bushier growth in general. This involves removing the growing tips of stems. For bush varieties, pinch off spent flowers and older stems where they meet other stems to maintain a shapely plant.
When cutting back overgrown or leggy growth, particularly for vining nasturtiums, trim the longest vines by 6 to 12 inches. This stimulates new growth, helping to fill in sparse areas and prevent the plant from becoming too sprawling. For very overgrown plants, you can cut back stems significantly, up to one-third of the plant’s height, to rejuvenate it and improve air circulation.
Post-Pruning Care
Water the plant thoroughly immediately after pruning. Nasturtiums prefer consistent moisture, especially during hot, dry periods, though they are somewhat drought-tolerant once established.
Monitor the plant for new growth. Ensure the plant receives sufficient sunlight, at least six hours of direct sun daily. Nasturtiums prefer well-drained soil and do not require extensive fertilization; overly rich soil can lead to more foliage and fewer flowers. If the soil is very poor, a light amendment with organic matter can be beneficial.