Nasturtiums are colorful, hardy annuals beloved by gardeners for their vibrant flowers and unique, peppery leaves. They are particularly well-suited for growing in Illinois, where the climate offers a suitable environment for these plants to thrive. This guide will walk you through everything you need to know about growing nasturtiums in Illinois, from selecting the right varieties to proper planting, care, and pest management.
Nasturtiums (Tropaeolum majus) are native to South America and belong to the family Tropaeolaceae. They come in various colors, including shades of orange, yellow, and red. The plant is known not only for its beauty but also for its culinary uses—both the flowers and leaves are edible and can add a spicy kick to salads and other dishes.
Edible Flowers and Leaves: Nasturtium’s leaves and flowers are safe to eat and can enhance culinary creations with their peppery flavor.
Pest Deterrent: Nasturtiums can repel certain pests such as aphids and whiteflies, making them a beneficial addition to vegetable gardens.
Attractive Ground Cover: Their sprawling nature makes nasturtiums excellent ground cover plants, helping to suppress weeds.
Ease of Growth: Nasturtiums are relatively low-maintenance, making them perfect for both novice and experienced gardeners.
When selecting nasturtium varieties to grow in Illinois, consider the following popular options:
Tall Varieties: These include ‘Jewel Mix’ and ‘Climbing Nasturtium.’ They can reach heights of 10-12 inches or more and are excellent for trellises or fences.
Dwarf Varieties: Varieties like ‘Alaska Mix’ or ‘Tip Top’ remain compact at around 8-10 inches tall. These are ideal for containers or small garden spaces.
Trailing Varieties: If you want a cascading effect, look for trailing types like ‘Orange Troika’ that work well in hanging baskets or window boxes.
Illinois has a varied climate that includes cold winters and warm summers. Nasturtiums thrive best in USDA Hardiness Zones 3-10, meaning they can be successfully grown across the state. However, they prefer conditions that avoid excessive humidity, which can lead to fungal diseases.
Nasturtiums prefer well-drained soil enriched with organic matter. A slightly acidic to neutral pH (6.0-7.0) is ideal. Avoid overly rich soils high in nitrogen, as this may lead to more foliage but fewer blooms.
These plants thrive in full sunlight and require at least 6 hours of direct sunlight per day. In shaded areas, nasturtium growth can become leggy and result in fewer flowers.
In Illinois, it’s best to start nasturtiums from seed after the last frost date, usually around mid-April to early May. This timing varies slightly depending on the specific region within Illinois; southern areas may have earlier planting dates than northern regions.
Direct Sowing: Sow seeds directly into the garden soil by planting them about ½ inch deep and spaced around 10-12 inches apart for taller varieties or 6-8 inches apart for dwarf varieties.
Starting Indoors: If you wish to get a head start on the growing season, you can start seeds indoors about 4-6 weeks before the last frost date. Transplant them outdoors once the danger of frost has passed.
If starting indoors, harden off your seedlings by gradually exposing them to outdoor conditions over a week before planting them in the garden. This process helps reduce transplant shock.
Nasturtiums prefer moderate watering; they do not thrive in overly wet soil. Water them regularly but allow the soil to dry out slightly between watering sessions. During hot summer days, they may require more frequent watering—especially if they show signs of drought stress such as wilting leaves.
Given their preference for poorer soils, nasturtiums do not require heavy fertilization. A light application of compost at planting time is often sufficient. Avoid using nitrogen-rich fertilizers as this may lead to lush foliage growth at the expense of flowers.
Regular deadheading (removing spent flowers) encourages more blooms throughout the growing season. Additionally, if nasturtiums become too sprawling or leggy, you can trim back some growth to encourage bushier growth patterns.
While nasturtiums are relatively pest-resistant due to their natural deterrent properties, they can still face challenges from aphids and spider mites:
Aphids: Regularly inspect your plants for aphid infestations; if found, spray them off with water or use insecticidal soap.
Spider Mites: Increase humidity around your plants by misting them or using a humidifier if spider mites become an issue.
Fungal Diseases: To prevent fungal issues like powdery mildew, ensure good air circulation by spacing plants appropriately and avoiding overhead watering.
Nasturtium leaves can be harvested once they reach a good size—generally when they are about 3-4 inches across—but ensure you leave enough foliage for the plant’s health. Flowers should be harvested when fully open; they have the best flavor at this stage. Both leaves and flowers can be used fresh or preserved in vinegar or butter.
Growing nasturtium in Illinois offers a rewarding experience filled with colorful blooms and culinary delights. Their resilience against pests makes them an ideal choice for novice gardeners as well as seasoned horticulturists looking to beautify their gardens sustainably.
With proper care—considering factors such as climate conditions, soil preferences, watering routines, and pest management—your nasturtiums will flourish beautifully throughout the growing season while adding vibrant colors and unique flavors to your garden plate!