Nasturtiums (Tropaeolum majus) are popular garden flowers known for their vibrant blooms and edible leaves, flowers, and seeds. These versatile plants are easy to grow and can add a splash of color to any garden or container. This comprehensive guide will cover everything you need to know about growing and caring for nasturtiums from seeds.
Understanding Nasturtiums
Botanical Background
Nasturtiums belong to the Tropaeolaceae family and are native to South and Central America. They are known for their bright, trumpet-shaped flowers that come in various shades of red, orange, yellow, and cream. Nasturtiums are also valued for their peppery-tasting leaves and flowers, which are often used in salads and garnishes.
Ideal Growing Conditions
Nasturtiums thrive in sunny locations with well-draining soil. They are relatively drought-tolerant and can grow in poor soils, making them ideal for a variety of garden settings.
Preparing to Grow Nasturtiums from Seeds
Selecting Seeds
Choose high-quality seeds from a reputable supplier. There are many varieties of nasturtiums to choose from, including:
- Dwarf Varieties: Such as ‘Alaska’ and ‘Tom Thumb,’ which are perfect for containers and small garden spaces.
- Trailing Varieties: Like ‘Jewel of Africa’ and ‘Gleam,’ which are great for hanging baskets and ground cover.
- Climbing Varieties: Such as ‘Tall Climbing Mix,’ which can be trained to grow on trellises and fences.
Seed Starting Timeline
Nasturtiums can be started indoors 4-6 weeks before the last expected frost date or sown directly into the garden after the danger of frost has passed.
Sowing Nasturtium Seeds
Materials Needed
- Seed starting mix
- Seed trays or pots
- Clear plastic covers or plastic wrap
- Spray bottle for misting
Steps to Sow Seeds
- Prepare the Seed Tray: Fill the seed tray or pots with seed starting mix. Moisten the mix slightly with a spray bottle.
- Sow the Seeds: Plant the seeds about 1/2 inch deep and cover them with soil. Space the seeds about 1-2 inches apart.
- Cover and Warm: Cover the tray with clear plastic to retain moisture and place it in a warm location with temperatures around 70-75°F (21-24°C).
- Light and Humidity: Ensure the seeds receive indirect light. Use grow lights if natural light is insufficient. Keep the soil moist by misting regularly.
Germination Process
Nasturtium seeds typically take 10-14 days to germinate. Once seedlings emerge, remove the plastic cover and provide bright, indirect light.
Transplanting Seedlings
Hardening Off
Before transplanting outdoors, gradually acclimate the seedlings to outdoor conditions over 7-10 days.
Planting Location
Choose a sunny location with well-draining soil. Prepare the garden bed by adding compost or aged manure to enrich the soil, although nasturtiums can thrive in poorer soils as well.
Spacing
Plant the seedlings 10-12 inches apart for dwarf varieties and 12-18 inches apart for trailing and climbing varieties.
Caring for Nasturtiums
Watering
Water the plants regularly to keep the soil consistently moist but not waterlogged. Once established, nasturtiums are relatively drought-tolerant and require less frequent watering. Mulch around the base of the plants to retain moisture and suppress weeds.
Fertilizing
Nasturtiums do not require heavy fertilization. In fact, too much fertilizer can lead to excessive leafy growth with fewer flowers. A light application of balanced fertilizer at planting time is usually sufficient.
Pruning and Training
For trailing and climbing varieties, provide support with trellises or fences and gently train the vines as they grow. Regularly pinch back the growing tips to encourage bushier growth and remove any dead or yellowing leaves to maintain plant health.
Dealing with Pests and Diseases
Common Pests
Nasturtiums can attract pests like aphids, caterpillars, and whiteflies. Inspect your plants regularly and treat infestations with insecticidal soap or neem oil.
Diseases
Nasturtiums are relatively disease-resistant but can be affected by fungal diseases like powdery mildew and downy mildew. Ensure good air circulation, avoid overhead watering, and plant in well-draining soil to prevent these issues.
Harvesting Nasturtiums
Flowers and Leaves
Nasturtium flowers and leaves are edible and can be harvested throughout the growing season. Pick flowers when they are fully open and leaves when they are young and tender.
Seeds
Nasturtium seeds can be harvested when the seed pods turn brown and dry on the plant. Collect the seeds and store them in a cool, dry place for future planting or culinary use.
Enjoying Your Nasturtiums
Nasturtiums are not only beautiful but also versatile in the kitchen. The flowers, leaves, and seeds have a peppery flavor that can add a unique twist to salads, sandwiches, and garnishes. Use fresh nasturtium flowers to decorate cakes and desserts, or pickle the seeds to use as a substitute for capers.
Conclusion
Growing nasturtiums from seeds is a rewarding experience that adds vibrant color and edible delights to your garden. With proper care and attention, these hardy plants will thrive and provide beautiful blooms throughout the growing season. By following the guidelines in this comprehensive guide, you’ll ensure your nasturtiums grow healthy and strong, bringing beauty and flavor to your outdoor space. Happy gardening!
