How to Grow Nasturtium in Wisconsin

Nasturtiums are vibrant, easy-to-grow annuals that add a splash of color to gardens and landscapes. With their bright flowers and lush foliage, they attract beneficial insects and can even be used in culinary dishes. For gardeners in Wisconsin, understanding how to cultivate nasturtiums effectively can lead to a bountiful and beautiful garden display. This article provides a comprehensive guide on growing nasturtiums in Wisconsin, from choosing the right varieties to caring for your plants.

Understanding Nasturtium

Nasturtium (Tropaeolum majus) belongs to the family Tropaeolaceae and is native to South America. Known for their striking flowers that come in shades of orange, red, and yellow, these plants are not just visually stunning; they also have a range of practical uses. The leaves and flowers are edible, with a peppery flavor similar to arugula, making them a popular addition to salads and garnishes.

In addition to their culinary uses, nasturtiums serve as companion plants. They repel certain pests like aphids and whiteflies, making them an excellent choice for organic gardening.

Choosing the Right Varieties

In Wisconsin’s climate, it’s essential to select the right variety of nasturtium that will thrive. There are two primary types:

1. Trailing Nasturtiums

These varieties produce long vines that can cascade over edges or climb structures. They are perfect for hanging baskets or trellises. Popular cultivars include:
– ‘Jewel Mix’: A blend of colors including orange, yellow, and red.
– ‘Peach Melba’: Features apricot-colored flowers with darker centers.

2. Bush Nasturtiums

Bush or compact varieties grow more upright and are better suited for garden beds or containers. Some recommended types include:
– ‘Alaska Mix’: Known for its variegated leaves with bright blooms.
– ‘Tom Thumb’: A dwarf variety that grows about 10 inches tall with vibrant colors.

When selecting seeds or plants, consider your garden space and aesthetic preferences.

When to Plant

In Wisconsin, the growing season typically lasts from late May through early September, but this can vary based on your specific location within the state (northern vs. southern). Nasturtiums thrive best when temperatures consistently reach 60°F or higher.

Starting Indoors vs. Direct Sowing

You can start nasturtium seeds indoors about 4-6 weeks before the last expected frost date (usually in late April for most of Wisconsin) or sow them directly into the garden after the frost has passed.

• Starting Indoors: Use biodegradable pots filled with seed starting mix. Plant seeds about 1 inch deep and keep them moist until germination.

• Direct Sowing: Once the soil has warmed up in late May, sow seeds about 1/2 inch deep in well-drained soil.

Preparing the Soil

Nasturtiums prefer well-drained soil with a slightly acidic to neutral pH (6.0 – 7.0). Here’s how to prepare your soil:

1. Location: Choose a sunny spot that receives at least 6 hours of sunlight daily.

2. Soil Amendments: Amend heavy clay soils with organic matter like compost or peat moss to improve drainage.

3. Testing Soil: Conduct a soil test if unsure about your soil’s nutrient levels — this will guide you on necessary amendments.

Planting Nasturtium Seeds

Once you have prepared your soil:

1. Create rows or mounds based on your intended planting style (bushes vs. trailing).
2. Space bush varieties about 10-12 inches apart; trailing varieties should be spaced further apart depending on their growth habit.
3. Water gently after sowing and keep the soil consistently moist but not waterlogged until seedlings are established.

Caring for Your Nasturtium Plants

Once planted, providing proper care is crucial for healthy growth.

Watering

• Nasturtiums do not require excessive watering; they prefer slightly dry conditions once established.
• Water deeply every week during dry spells but allow the top inch of soil to dry out between waterings.

Fertilizing

• Over-fertilization can lead to lush foliage at the expense of flowers.
• If needed, use a balanced organic fertilizer sparingly when plants are young (dilute half-strength).

Pest Management

Nasturtiums are usually pest-resistant due to their peppery taste but may still attract aphids or caterpillars:

• Introduce beneficial insects like ladybugs.
• Use insecticidal soap if infestations occur.

Pruning and Deadheading

To encourage continuous blooming:

• Regularly deadhead spent flowers.
• Pinch back leggy growth to promote bushier plants.

Harvesting Edible Parts

If you’re growing nasturtiums for culinary use:

1. Harvest flowers when fully open; they can be added fresh to salads or used as garnishes.
2. The leaves can also be harvested at any time during the growing season; they add a zesty kick to dishes.
3. Avoid harvesting too much at once — take only what you need to encourage continued growth.

Preparing for Winter

In Wisconsin’s colder climate, nasturtiums won’t survive winter due to frost:

• At the end of the growing season (usually late September), remove dead plant material from your garden.
• You may collect seeds from mature pods if you wish to grow them again next year.

Tips for Success

1. Companion Planting: Pair nasturtiums with vegetables like tomatoes and cucumbers to deter pests naturally.

2. Mulching: Apply mulch around plants to conserve moisture and suppress weeds.

3. Succession Planting: For continuous blooms throughout summer, consider sowing new seeds every few weeks until mid-summer.

4. Avoid Overcrowding: Ensure proper spacing between plants to allow air circulation which helps prevent fungal diseases.

Conclusion

Growing nasturtiums in Wisconsin is an enjoyable endeavor that yields beautiful blooms while providing edible options for culinary enthusiasts. By choosing suitable varieties, preparing the right soil conditions, and offering proper care throughout the growing season, gardeners can enjoy a thriving patch of these colorful plants from late spring until frost.

With minimal effort required and numerous benefits offered—both aesthetically and practically—nasturtiums prove themselves as an excellent choice for any Wisconsin gardener looking to enhance their outdoor spaces while reaping culinary rewards!