This Nasturtium can grow to a mature height of 40 to 60 inches. Start Nasturtium flower seeds in spring for blooms that last all summer through fall and up until the first frost. The blossoms on this variety of Tropaeolum are deep red. Both the rounded leaves and spurred flowers are edible. Nasturtiums are annuals native to South America. They are a versatile flower for the garden either climbing a post or cascading from a window box or hanging basket. Even though Nasturtium is an annual, it readily self-sows to bring blooms for the next season. It also has a fragrant flower that is known to attract butterflies.