Iresine, sometimes known as blood leaf, is a relatively uncommon plant, but still a cool one. I've seen these mostly in botanical gardens, where they stand out with their red leaves and interesting textures. In all, there are about 30 species of Iresine plants in the genus, all of them native to South America, especially Brazil. They range from small to medium sized shrubs, and most are perennial.
The flowers on these plants are unremarkable, consisting of small greenish or white flowers on small stems, but instead, they are commonly grown for their striking foliage.
Like other fleshy shrubs, it's possible to keep them smaller by pinching off tall shoots. In terms of culture, these are "warm house" plants and cannot tolerate lower temperatures or cold, dry air. They are best grown in window boxes or bathrooms, which often have warmth and humidity, or if you have a glasshouse they will thrive there.
Light: Smaller plants tend to thrive in partial shade, but as they grow they can tolerate more light. They are margin plants by nature, meaning they grow on the edge of forests and can withstand varied light levels.
Water: Regular moisture is essential. They aren't water plants, so don't waterlog them, but plants without adequate moisture will begin to develop brown leaf margins and dropping leaves.
Soil: Any good, fast-draining potting soil will likely do.
Fertilizer: Feed with a weak liquid fertilizer throughout the growing season.
Iresine should be repotted annually until they reach their mature size, then they can be repotted every other year or propagated to create new stock and discarded.
In the tropical landscape, they are often used as bedding plants, so it's a nice effect to grow a small clump of them in a container or to grow them in a mixed container with other tropical plants.
Of the 30 or so species, only a handful are actually grown indoors. These include:
- I. herbstii. This is a larger plant, native to Brazil, and probably not the best candidate for indoor growth. They grow to 6 feet tall. They have 3-inch leaves.
- I. lindenii. These shrubs stay around 3 feet in height and have more green and yellow in their leaves than I. herbstii. The leaves are striped red and narrow. Stunt them by pinching growing shoots.
- I. Wallisii. This is a popular cultivar of I. herbstii, with more rounded leaves in purple.
Aside from their interesting foliage, these plants are notable for the range of their common names. Besides blood leaf, they are known as the chicken gizzard plant, the beefsteak plant, and other descriptive names. They are more common in the Southern Hemisphere, which makes them novelties in the northern hemisphere. For container cultivation, these plants are good candidates to move outside during the warm growing season, then move them back in during the winter.
Because of their low tolerance for cold, dry air, they will need to be frequently misted and provided with adequate heat during the winter. They can tolerate less light in the winter months, so don't place them too close to a window. Iresine are vulnerable to pests including aphids, mealy bugs, scale, and white fly. If possible, identify the infestation as early as possible and treat with the least toxic option.
Blood leaf can be grown from seed if you can manage to find the seed. They are best purchased from online sources, as these plants are not especially common. They can also be easily propagated from fleshy stem-tip cuttings. For best success, take cuttings early in the season, use a rooting hormone, and provide bottom warmth and very high humidity.