A nasturtium is a type of low-growing, flowering herb that can be one of 80 or so different species of plants in the genus Tropaeolum. Originating in South America, they were discovered by Spanish Conquistadors in the mid-1500s and brought back to Spain, and then spread throughout Europe. They are a relatively hardy type of flowering plant that is usually an annual, but can self-seed in moderate growing conditions and come back each year as a perennial. Though the nasturtium tends to grow low to the ground and produce delicate-looking flowers, the petals of the flowers are quite hardy and the plant itself can be induced to climb along garden fences or trellises.
A typical nasturtium plant will grow to about 12 inches tall (0.3 meters) and can produce a variety of five-petaled flowers in many shades of color from red to yellow and white with many new varieties as of 2011 showing a mixture of colors in the petals. The flowers themselves are edible, and have been used for medicinal purposes by the natives of Peru for centuries, made into a tea to treat respiratory ailments, and as a natural antibiotic. They are high in vitamin C, and are often used in cooking as a colorful and spicy flavoring. One common use for the nasturtium flower is to make a vinegar sauce out of it for salads or use it as a key ingredient in a lemon-flavored butter. It is also common for the blossoms to be used in hors d'ouveres or as additions to cream cheese and guacamole-type dips, and both the leaves and seeds of the nasturtium, which have a peppery flavor, are edible as well.
Caring for nasturtiums includes looking for well-drained soil and not over-fertilizing them as they will grow large and produce few flowers. They work best as an edging plant for borders, and dwarf varieties exist that grow well in containers. Planting nasturtiums requires some patience if done from seed, as the shells of the seed are tough and may be slow to crack and germinate. It is recommended that the seeds be soaked overnight before planting to speed up this process. Nasturtium flowers are most abundantly produced by the plants when they are in full sun locations, but they will produce healthy growth with fewer flowers in conditions of partial shade as well.
One of the benefits of growing nasturtiums in gardens is that they serve as a natural repellant for some types of insects like beetles and caterpillars that feed on vegetables such as squash, cucumbers, and the brassica vegetable family that includes broccoli and cauliflower. Part of the benefit that they offer is that some species of insect pests like the cabbage white butterfly and dot moth will feed on the nasturtium plant itself and draw these insects away from other food crops in a garden space. The flowers of the plant are also known to attract bees and hummingbirds for the nectar that they produce, which adds additional pollination and beauty to flower and vegetable gardens where they are present.