The Tip Top Mahogany Nasturtium is a popular, compact variety known for its deep mahogany-red, velvety flowers that appear to float above golden-green foliage. This annual, or short-lived perennial in warmer climates, offers both ornamental beauty and culinary appeal, making it a versatile garden addition.
Growing Tip Top Mahogany Nasturtium
Light Needs
Tip Top Mahogany Nasturtium thrives best in full sun, with six to eight hours of direct sunlight daily for abundant flowering. While it can tolerate partial shade (three to six hours), flowering may be less prolific. In very hot regions, providing some afternoon shade can prevent leaf browning and maintain vigor.
Soil Preferences
This nasturtium prefers well-draining, moderately fertile to poor soil. Rich or overly fertile soil promotes excessive foliage growth at the expense of flowers. For particularly poor soil, a small amount of compost can provide adequate nutrients without over-enriching.
Watering
Consistent moisture, without waterlogging, is important, especially during dry periods. An average of one inch of water per week is typically sufficient. Once established, nasturtiums demonstrate some drought tolerance, but regular watering encourages more blooms. Avoid overwatering to prevent root rot.
Planting and Spacing
Plant seeds outdoors after all danger of frost has passed in spring, when soil temperatures reach at least 55°F (13°C). Sow seeds directly about 1/2 to 1 inch deep. For earlier blooms, start seeds indoors two to four weeks before the last expected frost, taking care during transplanting as their delicate roots prefer minimal disturbance. Given their compact, bushy nature, space plants 8-12 inches apart for proper air circulation and optimal growth.
Fertilization
Minimal fertilization is needed. High-nitrogen fertilizers promote lush foliage but fewer flowers. If blooms are sparse despite healthy foliage, a phosphorus-rich plant food, such as bone meal, may encourage flowering.
Beyond the Garden: Uses and Benefits
This nasturtium offers more than just visual appeal. All parts—leaves, flowers, and immature seed pods—are edible, possessing a distinctive peppery flavor reminiscent of watercress. They can be incorporated into salads, used as vibrant garnishes, or added to other culinary dishes. Beyond culinary uses, this compact nasturtium is well-suited for ornamental displays in containers, hanging baskets, and as a border plant. Nasturtiums also function as companion plants, particularly as a trap crop for pests like aphids, drawing them away from more desirable vegetable crops.
Ensuring Success: Common Tips and Troubleshooting
To encourage continuous blooming, regularly deadhead spent flowers. This prevents seed production, directing energy towards new blossoms. When harvesting for culinary use, pick fully opened flowers and young leaves for optimal flavor and texture.
Common pests include aphids, flea beetles, and caterpillars. Aphids are particularly attracted to nasturtiums, making them effective trap crops to divert pests from other plants. If aphid infestations become problematic on the nasturtiums, a strong spray of water can dislodge them, or insecticidal soap can be applied. While Tip Top Mahogany typically does not require support, excessive foliage growth or legginess can occur if soil conditions are too rich; proper soil fertility prevents this.