The easy-to-grow nasturtium (Tropaeolum majus) is an annual that brings warm colors to the garden. Its spurred flowers bloom in buttery yellow, deep red, burnt orange, and mahogany.
A few have contrasting streaks in the center of the flower. The rounded, light green foliage is attractive as well. Some leaves have creamy marbling (the Alaska Series) or hints of purple (‘Empress of India'). The bushy forms are dependable additions to border gardens, and vining forms cascade gracefully down the sides of hanging baskets or meander up supports.
Common name: Nasturtium, Indian cress
Botanical name: Tropaeolum majus
Plant type: Annual
Height: 3 to 10 feet, depending on cultivar
- Sun: Full sun
- Soil: Moderately fertile to poor soil
- Moisture: Average to dry
- Mulch: Add an inch of mulch to discourage weeds.
- Pruning: Deadhead spent blooms to encourage more flowering.
- Fertilizer: Usually fertilizer isn't needed. Overfertilizing will decrease flowering and increase foliage.
- The Alaska Series has marbled foliage and single flowers in yellow, orange, mahogany, or cream.
- The Gleam Series is a semi-trailing nasturtium with semi-double flowers in yellow, orange, red, and pink. It grows 16 inches tall.
- ‘Moonlight' has light yellow, single flowers. Grows 6 to 8 feet tall.
- ‘Peach Melba' is a dwarf, bushy form bearing semi-double, light yellow flowers with streaks of red in the center. It grows 9 to 12 inches tall.
- The Tom Thumb Series is a bushy form with single yellow, peach, and red flowers. It grows 10 inches tall.
- ‘Variegatus' has variegated foliage and red and orange flowers.
- ‘Vesuvius' has coral-salmon, single flowers and dark blue-green foliage. It's attractive in window boxes and containers.
- Add peppery-tasting nasturtium flowers and leaves to green salads. Use flowers to garnish desserts. Make sure no harmful chemicals have drifted on to the flowers and leaves you eat.
- Nasturtiums are a kid-friendly annual to start from seed. The seeds are large and easy to handle, they germinate quickly, and seedlings grow rapidly.
Pests and diseases
- Whiteflies and plant viruses occasionally attack nasturtiums.
- Sow seeds indoors in early spring.
- Sow seeds outdoors in midspring.
All in the family
- Tropaeolum azureum is a perennial climber in Zones 11 and 12. Its blue flowers have cream to yellow centers.
- T. speciosum (Scottish flame flower or flame nasturtium) is a perennial climber in Zones 8 to 11. It bears yellow flowers and palmate leaves and grows 10 feet tall.
Text by Mary Pestel, photo by Amy Sumner