Hoyas are members of the Asclepiad family, with a genus containing about 300 different species of tropical plants. Hoya plants are popular because they are easy to grow and because of their wide variety of leaves, flowers and textures. They bloom early to mid-summer and are hardy in USDA zones 10 to 12. Hoyas are often grown as indoor plants, and their common name is the wax plant.
The wax plant (Hoya carnosa) is an herbaceous perennial that grows 2 to 4 feet tall and requires full sun. The wax plant is also referred to as the honey plant. It is a climbing or trailing perennial; its trailing stems will climb counterclockwise around trellises. Stems can also cascade from hanging baskets. The wax plant has dark green leaves surrounding tight, round clusters of sweet-smelling flowers. The tiny white flowers, which bloom in the summer, are each only 1/2 inch in diameter.
Miniature Wax Plant
The miniature wax plant (Hoya bella) is a climbing variety that grows well in windows with southern or western exposure. Often planted in hanging baskets, this plant needs full sun and something that it can climb. This variety also has small white flowers with a sweet scent that are clustered around the green leaves. Miniature wax plants needs fertilizing only twice a year: in April and July.
Big Leaf Variety
Big-leaf hoya (Hoya imperialis) is one of the biggest and best-known hoya species. The most common varieties the large red-, brown- or purple-flowered plants. There are also some sub-varieties with pink and yellow flowers. The plant grows 3 to 4 feet tall, with solid stalks, and requires plenty of room to grow. This species, native to Borneo, requires bright shade and slightly dry soil.
Hoya meliflua is a type of succulent hoya plant. The very large flowers have dark round spots in the center that are actually sap secreted from the base of the middle stem. The flowers are large ,and if the plant is kept indoors, the sap can stain furniture and carpet and attracts bugs. The chocolate-scented blooms have a chestnut-red color. Its leaves can reach up to 12 inches long. This slow-growing variety requires bright light and infrequent watering.