How to Grow and Care for Nasturtiums: A Complete Guide

Nasturtiums (Tropaeolum) are among the most rewarding annuals you can plant. They bloom from early summer until the first frosts, offering a spectacular spectrum of colors—from bright orange, yellow, and red to subtle cream, salmon pink, burgundy, and crimson. Many varieties also feature striking marbled or mottled foliage, adding texture to any garden.

Why Grow Nasturtiums?

Beyond their beauty, nasturtiums are edible and garden-friendly:

• Edible parts: Flowers, leaves, and seed pods can be added to salads, soups, or pickled.
• Companion planting: Their leaves attract cabbage white butterfly caterpillars away from brassicas, and the flowers draw bees and other pollinators.
• Low maintenance: They thrive on poor, well‑drained soil and require minimal watering once established.

Choosing the Right Variety

There are three main growth habits:

• Bushy dwarf (Tropaeolum minus): Ideal for containers, hanging baskets, and front-of-border displays.
• Climbing (Tropaeolum majus): Train up obelisks or trellises; they twine beautifully over other plants.
• Ground cover: Spread across gravel or down slopes for a cascading effect.

Both types flourish in pots, making them perfect for beginners and children.

Where to Plant Nasturtiums

Red nasturtium flowers. Jason Ingram

Nasturtiums need at least 6 hours of direct sunlight daily. They prefer free‑draining, slightly acidic to neutral soil. In fact, the most prolific flowering occurs in poorer soils; overly fertile soil will produce lush foliage but fewer blooms.

Plant them:

• Front of borders or on obelisks.
• As companion plants in vegetable beds.
• Cascading from raised beds or pots.

When and How to Sow Seeds

Sow in early spring (March–May) while protecting seeds from frost. For a late flowering season that extends to the first frosts, sow later in the season.

Sowing Directly in the Ground

1. Rake the soil to a fine, weed‑free bed and water lightly before sowing to keep seeds from washing away.
2. Plant seeds 1.5 cm deep, spaced about 10 cm apart. Use your finger or a bamboo stick to create shallow holes.
3. Cover lightly with soil.
4. When seedlings appear (≈2 weeks), thin them to 30 cm spacing to give room for mature plants.

Alternatively, scatter seeds around the garden where you’d like them to appear, such as the edges of raised beds or large containers.

Sowing in Pots

Use 9 cm pots and plant one seed per pot. Grow seedlings indoors or on a sunny windowsill, harden them off, and transplant outside in late spring for earlier blooms.

Transplanting Seedlings

Nasturtiums are often sold in small pots from garden centres. When transplanting:

• Dig a hole the same depth as the pot and place the plant so the leaf crown sits at soil level.
• Water thoroughly after planting.

In Containers

Mix two‑thirds peat‑free compost with one‑third fine gravel or grit to reduce fertility and improve drainage. Plant as above and keep the soil evenly moist.

Care and Maintenance

Nasturtiums are almost self‑sufficient. In the ground, they rarely need extra watering. In pots, maintain moist, but not soggy, compost. Do not fertilise, as this can reduce flowering. Regular deadheading encourages a longer blooming period.

Harvesting and Storage

All parts are edible. Flowers and young leaves have a peppery flavor similar to watercress, making them excellent salad additions. Seed pods can replace capers—pick when green and pickle in vinegar.

Collect ripe seeds, store them cool and dry, and sow the next year. In mild climates, nasturtiums will self‑seed, so you may see new seedlings in spring.

For recipe inspiration, see Olive Magazine’s collection of nasturtium dishes.

Common Problems & Solutions

Mustached mandrake insects (mandibul insects) and aphids may appear. Control by:

• Scraping off mandibul mandible eggs and early caterpillars.
• Spraying a jet of water or encouraging natural predators such as ladybirds, hoverflies, and lacewings.

Buying Nasturtiums

• Seeds are widely available online. Top retailers: Thompson & Morgan, Suttons, and Crocus.
• Choose from bushy or climbing types depending on space.
• Seedlings can be purchased from garden centres in late spring.

Frequently Asked Questions

Do nasturtiums grow back every year? They are annuals and die with frost, but they readily self‑seed, so you’ll often see new plants next spring.

Can nasturtiums be planted next to brassicas? Yes—planting them nearby can divert cabbage white caterpillars away from your brassicas.

Top Nasturtium Varieties to Try

Nasturtium ‘Black Velvet’

Tropaeolum minus ‘Black Velvet’ is a compact plant with velvety dark‑red flowers. Height × Spread: 30 cm × 45 cm. Buy at Crocus.

Nasturtium ‘Phoenix’

Tropaeolum minus ‘Phoenix’ features split petals in red, orange, and yellow. Height × Spread: 30 cm × 30 cm. Buy at Thompson & Morgan.

Nasturtium ‘Empress of India’

Tropaeolum minus ‘Empress of India’ offers crimson‑red flowers and dark leaves. Height × Spread: 25 cm × 45 cm. Buy at Thompson & Morgan.

Nasturtium ‘Orange Troika’

Tropaeolum majus ‘Orange Troika’ climbs or trails with vivid orange blooms and marbled foliage. Height × Spread: 30 cm × 1.5 m. Buy at Suttons.

Nasturtium ‘Alaska Series’

Tropaeolum minus ‘Alaska Series’ displays yellow, cream, orange, and red flowers. Height × Spread: 25 cm × 45 cm. Buy at Crocus.

Nasturtium ‘Ladybird’

Tropaeolum minus ‘Ladybird’ sports cream/yellow flowers with deep‑red throat spots. Height × Spread: 30 cm × 40 cm. Buy at Thompson & Morgan.

Nasturtium ‘Baby Deep Rose’

Tropaeolum minus ‘Baby Deep Rose’ is a compact bush with deep crimson blooms. Height × Spread: 20 cm × 20 cm. Buy at Thompson & Morgan.

Nasturtium ‘Bloody Mary’

Tropaeolum minus ‘Bloody Mary’ features splotched and striped flowers in deep red, yellow, and cream. Height × Spread: 30 cm × 60 cm. Buy at Crocus.