full sun, part sun
Bloom Period and Seasonal Color
summer to fall in colors such as orange, yellow, red, cream and bicolor
Mature Height x Spread
1 to 4 feet x 12 to 18 inches
Edible, attracts beneficials, deer resistant
Nasturtiums are a fast growing and flowering annual that can give your garden a tropical touch. There are two types of nasturtiums; bush and trailing. The bush types stay in a 1 to 2 foot mound and are perfect for small spaces and containers. Trailing varieties can grow 4 to 5 feet tall and have to be trained up a fence, trellis or down a wall. They don’t attach themselves to a structure like a morning glory or grape vine. The round, water lily-like leaves are green or sometimes variegated. The trumpet-shaped flowers come in bright colors such a red, orange and yellow. Nasturtium flowers and leaves are edible with a peppery flavor. I love adding them to salads, soups and stir-fries.
Where, When and How to Plant
Plant nasturtium seeds directly into well-drained soil in a full to part sun location after all danger of frost has passed. Nasturtiums don’t like being transplanted so if you start seeds indoors or buy seedling, be sure to use a biodegradable pot so you won’t disturb the roots. Consider nicks seeds and soaking them in warm water the night before sowing to hasten germination. Plant bush types a foot apart. Plant trailing types near a fence, trellis, wall or structure where they can be trained vertically or off a railing where they can cascade. Nasturtiums will create a mass of foliage so give them some room apart from other low growing flowers.
Keep plants well watered and don’t over fertilize. Too much fertilizer will produce lush, large leaves but fewer flowers and they will be later blooming. Keep plants well weeded until they get established.
Regional Advice and Care
Nasturtiums need little care once established. Aphids can sometimes be a problem on young leaves. Spray insecticidal soap to reduce the damage. During hot, dry summers, nasturtium leaves may get ratty-looking. Either cut back the plant so it grows healthier leaves for fall or consider planting a new crop of nasturtiums in mid summer for autumn flowers.
Companion Planting and Design
Train trailing varieties by tying up the stems to a trellis or wire. Mounding varieties look great in containers, window boxes or in front of flower borders. Since they’re edible, consider planting nasturtiums in the vegetable and herb garden to remind you to eat the tasty foliage and flowers. Trailing varieties can also be trained to climb in among shrubs, such as junipers and yews, offering some unexpected flower color in summer.
‘Alaska Series’ features dwarf, bushy plants with variegated foliage. The ‘Whirlybird Series’ has large, double flowers on bushy plants. ‘Empress of India’ has vivid scarlet colored flowers on blue-green colored leaves. ‘Moonlight’ is a yellow flowered trailing variety. It pairs well with blue morning glories.
Excerpted from my book, New England Getting Started Garden Guide.