Overview

Nasturtiums are vibrant and versatile flowering plants that add a splash of color and a touch of culinary delight to any garden. With their edible leaves and flowers, they are a favorite among gardeners seeking both beauty and functionality. This comprehensive guide will provide you with all the essential knowledge and techniques to successfully grow and care for these charming plants.

Varieties and Uses

The diverse family of nasturtiums encompasses over 80 species, offering a wide range of growth habits and flower colors. From bushy ground covers to trailing varieties that cascade over edges and walls, there’s a nasturtium suited for every gardening need. Their edible leaves and flowers, with a distinctively peppery tang, make them a culinary delight. They are often used in salads, as a garnish, or even as a substitute for watercress.

Planting and Propagation

Nasturtiums thrive in well-drained soil with a pH between 6 and 8. They prefer full sun but can tolerate partial shade. To start growing nasturtiums, you can either sow seeds directly in the garden or purchase seedlings from a nursery. Seeds germinate quickly and produce blooms within a short period.

If you desire to propagate new plants, you can easily do so by taking cuttings from mature nasturtiums. Simply select a healthy stem with at least three leaves, dip the cut end into rooting hormone, and insert it into a pot filled with potting soil. Keep the soil moist and provide ample sunlight for successful rooting.

Care and Maintenance

Nasturtiums are relatively low-maintenance plants, requiring minimal care to thrive. Water them regularly, especially during hot and dry weather. Fertilizing is generally not necessary, as they prefer soil that is not overly rich.

Pruning can help promote new growth and flowering. For trailing varieties, trim the longest stems by 6 to 12 inches mid-summer and again in late summer. For bushy varieties, pinching off spent flowers and dried leaves will enhance their overall appearance.

Pests and Diseases

Aphids are common pests that can infest nasturtium plants. To control them, use a strong blast of water from a garden hose or apply a non-toxic spray made from diluted vinegar or essential oils. Planting catnip alongside nasturtiums can also deter these pests.

Bacterial leaf spot is a disease that can affect nasturtiums under improper conditions. To prevent or minimize this issue, provide ample airflow between plants and water with drip irrigation rather than sprinklers.

Troubleshooting Common Problems

• Lack of Blooms: If your nasturtium plant is not flowering, it may be due to excessive soil fertility. Reduce soil fertility by avoiding fertilizers and consider pruning the plant to encourage flower production.
• Root Rot: Nasturtiums prefer well-drained soil. If the soil is waterlogged, the plant may develop root rot. Ensure proper drainage by choosing a planting location with sandy soil or adding stones or pebbles to the bottom of containers.
• Flower Obstruction: Some nasturtium varieties have a growth habit that obstructs flower production. Choose varieties that hold their flowers above their leaves to allow sunlight to reach the buds.

Companion Planting

Nasturtiums are excellent companion plants in the vegetable garden. Their airborne phytochemicals deter a wide range of pests, including whiteflies, squash bugs, aphids, beetles, and cabbage loopers. By planting nasturtiums near vulnerable vegetables, you can naturally protect them from these harmful insects.

Culinary Uses

The leaves and flowers of nasturtiums are edible and add a unique peppery flavor to dishes. They can be used in salads, sandwiches, dips, and as a garnish for desserts. The seeds can also be pickled or pressed for oil.

Additional Tips

• Sow nasturtium seeds directly in the garden after the last spring frost.
• Start seeds indoors two to four weeks before the average last spring frost date for earlier blooms.
• Use peat or paper pots when starting seeds indoors to reduce transplant shock.
• Plant nasturtiums in containers for a trailing or climbing effect.
• Deadheading spent flowers will encourage continued blooming.
• Allow healthy plants to reseed themselves for a self-sustaining population in subsequent years.