Are you looking for a flowering plant that does more than flower? Try nasturtiums.
A ground cover that does more than cover? Nasturtiums again.
These Central American plants bring vivid color to the yard, add a peppery kick to salads and garnishes, and repel whiteflies and aphids.
“Nasturtium” derives from the Latin word “trophaeolum,” meaning trophy, a nod to their shield-shaped leaves and bold flowers. Indigenous peoples first cultivated nasturtiums in Central and South America for culinary and medicinal purposes.
Today, nasturtiums grow worldwide. Gardeners value them for their low-maintenance nature, culinary applications, and ability to attract pollinators like bees, butterflies, and hummingbirds.
Nasturtium Varieties
There are two main nasturtium types:
- Trailing or Climbing Nasturtiums: These varieties, like Tropaeolum majus, are perfect for trellises, fences, or hanging baskets. They can grow long vines up to 10 feet.
- Dwarf or Bush Nasturtiums: Compact and ideal for borders or containers, these varieties, such as Tropaeolum minus, grow to about 12 inches tall and wide.
Popular varieties include ‘Alaska’ (variegated foliage), ‘Jewel Mix’ (double blooms), and ‘Tip Top Apricot’ (bright orange flowers). Choose one based on your garden space and desired visual impact.
Nasturtiums make excellent cover plants, border plants, or companion plants in a landscape.
Optimal Growing Conditions
Light
- Nasturtiums love the sun! Plant them in an area that receives at least 6–8 hours of direct sunlight daily.
- While they tolerate some shade, their blooms will be less prolific.
Temperature
- Nasturtiums prefer warmer weather and are frost-sensitive. They grow best in temperatures between 55°F and 75°F.
- Wait until the last frost has passed before planting.
Close-up of crimson nasturtium flowers.
Soil
- Nasturtiums thrive in poor to average, well-draining soil.
- Avoid overly rich soil, which encourages leaf growth at the expense of flowers.
- Aim for a slightly sandy or light, loamy soil.
Planting Nasturtiums
- Plant nasturtium seeds outdoors in spring once the soil has warmed to around 60°F.
- Alternatively, you can start them indoors 4–6 weeks before the last frost.
- Plant seeds 1 inch deep and 10–12 inches apart for climbing varieties or 8–10 inches apart for bush varieties.
- Water the soil lightly after planting to keep it moist but not drenched.
- Provide a trellis or support structure early to guide growth for climbing nasturtiums.
- Once established, nasturtiums can tolerate some drought. However, consistent watering promotes more flowers and prevents wilting in hotter months.
You can also start new plants by cutting stems from existing ones. Cut a 4–6 inch piece and place it in well-draining soil. Keep the soil moist and wait for new growth to appear.
Dried nasturtium seeds ready for planting.
Nasturtium Care
Nasturtiums require minimal care once established.
Water
They can tolerate some drought, but regular watering encourages more blooms.
- Water at the base of the plant. Avoid wetting the leaves to prevent fungal diseases.
- Allow the soil to dry out between waterings. Consistently wet soil can lead to root rot.
Fertilizer
- Nasturtiums don’t require much fertilization, especially if planted in average soil.
- A light application of a balanced fertilizer every 4–6 weeks can promote healthier plants and more blooms.
Orange blossoms on a climbing nasturtium plant.
Pruning & Deadheading
- Pruning isn’t necessary for nasturtiums but can promote a more compact and bushy growth.
- Deadhead (remove spent flowers) regularly to encourage continuous blooming.
Pest & Disease Management
- Nasturtiums are pest-resistant but may occasionally attract caterpillars, aphids, and whiteflies. Handpick larger pests and use an insecticidal soap for smaller ones.
- Plants may also develop fungal diseases in overly wet conditions. To prevent this, avoid overhead watering and improve air circulation around plants.
Culinary Uses
Nasturtiums aren’t just pretty flowers; they’re edible too! Their leaves, flowers, and seeds have a peppery, watercress-like flavor. Use them as:
- A colorful garnish for salads and other dishes
- A flavorful addition to pesto or compound butter
- An ingredient in flavored oils or vinegars
Tip: Pick the flowers early in the day when they’re most fragrant and potent.
Bringing Nasturtiums Indoors
Nasturtiums can also be grown indoors as houseplants during colder months.
- Use a well-draining potting mix and place them in an area with ample sunlight.
- Water regularly, but allow the soil to dry out between waterings.
- Fertilize lightly every 4–6 weeks with a balanced fertilizer.
- Pinch back the stems to promote bushier growth and remove spent flowers regularly.
With enough sunlight, nasturtium can be grown indoors.
FAQs: Growing Nasturtiums
Q: Are nasturtiums perennial or annual?
Nasturtiums are treated as annuals in most climates but can act as perennials in frost-free zones.
Q: How can I collect nasturtium seeds?
Once the flowers fade, you’ll find round, green seed pods. Allow them to dry on the plant, then gently harvest and store them in a cool, dry place.
Q: Can nasturtiums grow in containers?
Yes, as long as the pot has good drainage. Use a lightweight, well-draining potting mix and leave enough space for the plants to spread. Dwarf varieties are well-suited for container gardening.
Q: Why are my nasturtium leaves turning yellow?
Yellowing leaves can indicate overwatering, poor drainage, or nutrient deficiency. Ensure the soil dries out between waterings, and avoid using overly rich soil or excessive fertilizer.
Q: Do nasturtiums attract beneficial insects?
Nasturtiums attract pollinators (bees and butterflies) and predatory insects like ladybugs, which help control garden pests like aphids.
Q: How long does it take nasturtium seeds to germinate?
Nasturtium seeds typically germinate within 7–14 days if planted in warm, moist soil. Pre-soaking the seeds in water for 12–24 hours before planting can improve germination.
Q: Can I grow nasturtiums alongside vegetables?
Nasturtiums are excellent companion plants. They can help repel pests like whiteflies, aphids, and squash bugs, making them ideal for planting near vegetables like tomatoes, cucumbers, and brassicas.
Q: What should I do with nasturtiums at the end of the growing season?
You can compost the plants to enrich the soil. Collect and dry the seed pods before frost if you want to save seeds for the following year. Alternatively, if the plants are in pots, you can bring them indoors to extend their life.