What are Nasturtiums?

Nasturtiums are flowering plants that belong to the genus Tropaeolum. The most common variety is Tropaeolum majus, which is native to South America. They are commonly used in companion planting, also known as coplanting, to repel pests from other plants. The plant is also popular as a culinary ingredient, as its leaves and flowers add flavor to salads and other dishes.

These edible flowers are repel pests from other plants. Nasturtiums produce a chemical called cucurbitacin, which is a bitter substance that deters many kinds of pests. When planted near other plants, the cucurbitacin can help protect the other plants from being eaten by pests. Nasturtiums also attract beneficial insects, such as ladybugs and bees to the garden.

The plants that benefit from coplanting with nasturtium are cucumbers, squash, and melons. These plants are especially susceptible to pests, so the cucurbitacin redirects pesky insects to the nasturtium for easier removal.

What are nasturtiums? Black Velvet (deep red) nasturtium flowers shown against green pad leaves
What are Nasturtiums? Climbing Phoenix Nasturtiums from Renee's Garden

Nasturtiums can be planted in the spring or fall in zone 10b. They should be planted in a bright, but partially shady location in southern California, with well-draining soil. Frequent pruning keeps the plants tidy and productive.

There are many different varieties of nasturtiums, with different colors and patterns. Some of the most popular varieties include T. majus ‘Alaska’, T. majus ‘Empress of India’, and T. majus ‘Jewel’. They are also available in a dwarf variety, which is perfect for small gardens or container gardening.

Nasturtiums are not only beautiful flowers but are popular as a culinary ingredient. The leaves and flowers of nasturtiums add flavor to salads, soups, or as garnishes for a variety of dishes. The seeds can also be pickled, like capers. The leaves are often used as a substitute for arugula, mizuna, or watercress in salads and sandwiches. The flowers are most frequently used to decorate cakes and other desserts. With their vibrant colors and unique flavor, they are a great addition to any dish. Whether you’re using nasturtiums to repel pests or adding them to your favorite recipe, they are a versatile and beautiful plant that everyone can enjoy.