In the world of home gardening, only a few plants offer the same mix of aesthetic beauty, culinary value, and ease of care as the nasturtium. From trailing vines that spill over containers to bushy groundcover varieties, nasturtiums are not just vibrant—they’re versatile. A neighbor once gifted me nasturtium seeds, and I have grown them in everything from kitchen window pots to permaculture plots. I can attest—they’re some of the most rewarding plants out there.
What Are Nasturtium Plants?
Nasturtiums (Tropaeolum majus and Tropaeolum minus) are vibrant flowering plants native to South and Central America, particularly the Andes region from Bolivia to Colombia. These plants are known for their bright, jewel-toned flowers and distinctive round leaves. It’s important not to confuse them with the watercress genus Nasturtium in the Brassicaceae family, as nasturtiums belong to the Tropaeolaceae family.
Quick Facts:
- Botanical Name: Tropaeolum majus (trailing) and Tropaeolum minus (dwarf)
- Common Names: Indian cress, monk’s cress
- Plant Type: Annual in most climates, perennial in USDA zones 9–11
- Edibility: The Entire plant (flowers, leaves, and seeds) is edible
Nasturtiums play a dual role in gardens: they are both ornamental and incredibly useful. They thrive in poor soils, require minimal care, and are naturally resistant to many pests, making them beneficial when planted alongside vegetables.
Historical and Cultural Roots
Nasturtiums have a rich history that begins in the Andes of South America. Indigenous communities, such as the Incas, valued them not just for their vibrant appearance but also for their medicinal properties. They used nasturtiums to treat wounds and respiratory issues, recognizing their natural antibiotic qualities.
In 1569, Spanish botanist Nicolás Monardes introduced nasturtiums to Europe. The plant’s unique appearance inspired Swedish botanist Carl Linnaeus to name it Tropaeolum, likening its leaves to shields and its flowers to blood-stained helmets, reminiscent of Roman victory trophies.
Throughout history, nasturtiums have been valued for their health benefits. Studies have shown that they contain compounds like isothiocyanates, flavonoids, and vitamin C, which contribute to their antimicrobial and anti-inflammatory effects. For instance, research indicates that nasturtium extracts can suppress inflammatory pathways in human immune cells, offering potential therapeutic applications.
Today, nasturtiums continue to be appreciated both for their beauty and their health benefits. Their edible flowers and leaves are rich in nutrients, making them a valuable addition to modern diets and herbal remedies.
Culinary Uses of Nasturtiums
Nasturtiums offer a delightful peppery flavor that can elevate everyday dishes. Their leaves and blossoms are entirely edible, with a taste reminiscent of watercress or radish microgreens, making them a favorite among chefs and home cooks alike.
Chef Kristie Jameson shares, “I use nasturtium blossoms in my catering business all the time. They add both a burst of color and a zingy flavor profile that guests love.” Similarly, Farmer Lee Jones describes nasturtium leaves as “real head-bangers,” noting their wasabi-like kick that surprises the palate.
These versatile flowers can be used in various culinary applications. They add zest to salads, pestos, and infused vinegars. The unripe seed pods can be pickled to create a condiment similar to capers. Additionally, nasturtiums are rich in vitamin C and lutein, contributing to their nutritional value.
The popularity of edible flowers, including nasturtiums, has been on the rise, with more chefs incorporating them into their menus to enhance both flavor and presentation. Whether you’re garnishing a salad or experimenting with new recipes, nasturtiums offer a unique combination of beauty and taste that can transform your culinary creations.
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Growing Nasturtiums: Getting Started
One of the biggest appeals of nasturtiums is how low-maintenance they are. Here’s what you need to know to start growing your own:
1. Choose the Right Variety
Nasturtiums come in various forms, each suited to different gardening needs:
- Tropaeolum majus: This trailing variety is perfect for hanging baskets or sprawling borders, adding a cascading effect to your garden.
- Tropaeolum minus: A more compact option, ideal for pots and small spaces. Varieties like ‘Baby Rose’ and ‘Baby Gold’ are known for their petite size and vibrant blooms, making them excellent choices for container gardening.
2. Pick a Planting Site
Selecting the right location is crucial for healthy growth:
- Sunlight: Full sun is ideal, though partial shade is acceptable. However, too much shade can reduce flowering.
- Soil: Nasturtiums prefer well-draining soil that isn’t overly rich. Excessive nutrients can lead to lush foliage at the expense of flowers.
3. When and How to Plant
Timing and planting techniques play a significant role:
- Timing: Direct sow seeds outdoors after the last frost date. Soil temperatures should be between 55°F and 65°F (12°C to 18°C) for optimal germination.
- Preparation: Soak seeds overnight to enhance germination rates.
- Planting: Sow seeds about ½ inch deep and space them 10–12 inches apart. Seedlings typically emerge within 7–10 days.
Care Tips for Thriving Nasturtiums
Watering
Nasturtiums prefer consistent moisture but dislike soggy conditions. Water them when the top inch of soil feels dry, ensuring the soil drains well to prevent root rot. Overwatering can lead to yellowing leaves and reduced flowering. In particularly hot climates, mulching can help retain soil moisture.
Fertilizing
These plants thrive in lean soils. Avoid fertilizing unless growth appears stunted. Excess nitrogen can result in lush foliage at the expense of blooms. If needed, a light application of a balanced, low-nitrogen fertilizer can support growth without hindering flowering.
Pest & Disease Management
Nasturtiums naturally deter pests like aphids, whiteflies, and squash bugs, making them excellent companion plants. However, they can attract cabbage worms and leaf miners. To manage these pests, remove affected leaves and consider using neem oil or insecticidal soap as needed. Regular monitoring helps catch infestations early.
Support Structures
Trailing varieties benefit from trellises or supports to encourage vertical growth and prevent sprawl. Compact, bushy types typically don’t require support and are well-suited for containers or garden borders.
Pruning and Deadheading
Regularly remove spent flowers to promote new blooms and prevent self-seeding. Pinch off yellowing or damaged leaves to maintain plant health. Pruning leggy growth encourages a fuller, bushier appearance. Use clean, sharp tools to make precise cuts, and perform these tasks during cooler parts of the day to minimize stress on the plants.
Trap Cropping, Companion Planting and Permaculture Benefits of Nasturtiums
Nasturtiums are powerful allies in sustainable gardening. One of their standout roles is as a “trap crop.” This means they attract pests like aphids, whiteflies, and squash bugs away from more vulnerable plants, effectively serving as a decoy. By luring these pests, nasturtiums help reduce infestations on neighboring crops, minimizing the need for chemical pesticides. This method of planting, called trap cropping, has been proven as an effective integrated pest management strategy.
In companion planting, nasturtiums pair well with a variety of vegetables, offering both protective and aesthetic benefits. Some of their best companions include:
- Tomatoes: Nasturtiums can deter aphids and whiteflies, common pests that plague tomato plants.
- Zucchini and Squash: These flowers repel squash bugs and beetles, safeguarding your squash plants.
- Cabbage and Other Brassicas: By attracting pests like cabbage worms, nasturtiums protect cabbage, broccoli, and kale from infestations.
- Cucumbers: Nasturtiums help repel cucumber beetles and improve overall plant health.
Garden expert Jess from The Cool Down emphasizes the role of nasturtiums as sacrificial plants: “Nasturtiums act as a sacrificial plant, preventing pests from destroying produce growing nearby. They attract caterpillars away from brassicas and also attract predators, such as ladybirds and hoverflies, that help control aphid populations.”
In permaculture, nasturtiums not only serve as trap crops and companion plants but also attract beneficial insects like pollinators and predatory insects, enhancing the overall health and productivity of the garden ecosystem.
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Harvesting and Saving Seeds
When to Harvest
- Leaves: You can start harvesting the leaves anytime after the plant has matured, usually around 4–6 weeks after germination. The younger the leaves, the milder the flavor—perfect for salads and sandwiches.
- Flowers: Pick the flowers once they’re fully open. This is when they’re most vibrant and flavorful. I often grab a few in the morning after the dew dries off—they look stunning tossed on a plate of pasta or floating in a summer cocktail.
- Seeds: You’ll notice fat, greenish seed pods forming where flowers once were. Let them ripen on the plant until they fall off naturally or come away easily when gently tugged. They’ll usually turn a pale tan or brown when they’re ready.
Seed Saving Tips
Saving nasturtium seeds is wonderfully easy—and honestly, kind of addictive. Letting them dry fully on the plant is ideal, but if frost or rain threatens, you can pull them early and finish drying them indoors on a paper towel or mesh tray.
Once dry, store them in a cool, dry place—an old envelope, small jar, or seed packet will do the trick. Label with the variety and date, and you’re all set. Well-cared-for nasturtium seeds can stay viable for up to 5 years, though I’ve had great results even after 3–4 years in storage.
Common Challenges and Solutions
1. Big Leaves, But No Flowers?
- Problem: If your nasturtiums are putting out loads of leafy growth but not a single flower in sight, it’s likely because the soil is too rich. These plants actually prefer poorer soils. When there’s too much nitrogen (often from fertilizers), they focus all their energy on leaves instead of blooms.
- What You Can Do: Hold off on feeding them. Unless your plant looks like it’s truly struggling, skip the fertilizer. If needed, go for something with low nitrogen and higher phosphorus to encourage blooming.
2. Yellowing or Droopy Leaves
- Problem: This is often a sign of overwatering or soil that doesn’t drain well. When the roots stay too wet, they can start to rot, and you’ll notice wilting or yellow leaves.
- What You Can Do: Make sure your soil drains well and let the top inch dry out before watering again. If you suspect root rot, gently unpot the plant, cut off any mushy or blackened roots, and replant in fresh, dry soil.
3. Unwelcome Pests (Like Caterpillars or Aphids)
- Problem: Caterpillars and tiny pests like aphids or spider mites sometimes snack on nasturtiums, especially in warmer months.
- What You Can Do: Pick off caterpillars by hand if there aren’t many. For a bigger pest problem, neem oil works well. Just follow the label, spray in the evening or early morning, and avoid hitting the leaves during full sun to prevent damage.
4. White Spots on Leaves (Powdery Mildew)
- Problem: If your leaves start getting a white, powdery coating, that’s likely powdery mildew, common in humid conditions.
- What You Can Do: Give your plants some breathing room by spacing them out. Avoid watering the leaves and stick to the base. Remove affected foliage and, if needed, use an organic fungicide.
5. Slow or Stunted Growth
- Problem: If your nasturtiums just aren’t taking off, check the basics: soil and sunlight. Compacted soil or low light will definitely slow them down.
- What You Can Do: Loosen up the soil and make sure your plants are getting at least 6 hours of direct sunlight daily. They thrive in full sun!
Conclusion: Why Every Gardener Should Try Nasturtiums
Nasturtiums have come to represent more than just a pop of color in my garden. They embody resilience, usefulness, and joy. From Evelyn’s gifted seeds to the countless salads and bouquets since, they’ve brought connection and creativity into my life.
Whether you’re a seasoned gardener or just starting out, nasturtiums are a perfect plant to grow. Their low maintenance needs, edible versatility, and pollinator-friendly blooms make them a must-have in any green space.
Actionable Takeaways:
- Start with direct sowing in spring
- Use poor soil for more flowers
- Eat the flowers and leaves for a peppery zing
- Use them in companion planting for pest control
Grow them once, and you’ll never want a summer without nasturtiums again.
