How to Grow and Care for Hoyas
Introduction to Hoyas
Hoyas are easy-care houseplants popular for their attractive foliage and fragrant blooms. Long favored by generations of houseplant aficionados, hoyas are experiencing a surge in popularity as more gardeners embrace indoor growing. The common name, wax plant, refers to the succulent, waxy leaves and flowers. Most hoyas produce long vines and grow well in hanging baskets or trained to a trellis.
About Hoyas
Durable, adaptable, and carefree, hoyas are long-lived houseplants that will happily adorn a table, shelf, or windowsill with their trailing vines draping over the sides of their planters or trained to grow upright on a trellis. Although there are hundreds of Hoya species, the most commonly available types are cultivated varieties of Hoya carnosa, many of them prized for their variegated foliage in shades of green, white, cream, and pink.
In addition to their handsome foliage, hoyas also produce sweetly scented blooms. The small, star-shaped flowers are borne in clusters that hang from the plant like ornaments. The flowers form on long stems, called spurs or peduncles, and produce sugary nectar that is so abundant it may drip onto the floor! Hoya’s other common names, porcelain flower and honey plant, refer to their sculptural blooms and sweet nectar.
Hoya plants are native to tropical and subtropical regions of Asia and Australia. In the wild, most species are epiphytes that grow on tree branches, where they get the water and nutrients they need from the air and from organic matter that collects in the branch crevices. (They don’t harm their host trees; they simply use them as supports for the vines as they climb to gather as much sunlight as possible in the dense tree canopy.)
The white sap exuded by many types of hoyas after pruning can irritate skin; wear gloves when handling the plant.
Pronunciation: HOY-uh
Growing Zones for Hoyas
Hoya can be grown outdoors year-round in USDA Hardiness Zones 9-11. In colder regions, they can be grown as houseplants and, if desired, brought outdoors to a part-shade location during summer. Bring plants indoors when temperatures are predicted to drop into the 50s.
Choosing a Site to Grow Hoyas
In the wild, most hoyas grow in the dappled light of a tree canopy. When grown as a houseplant, this translates to bright, indirect light; an hour or two of direct sunlight in morning or late afternoon is fine. Good spots include east-facing windows or a few feet back from south- or west-facing windows. Prolonged or mid-day direct sun can bleach or damage leaves, while insufficient light may inhibit flowering.
Hoya thrive at normal to cool room temperatures and may suffer from chill damage if temperatures drop below 50 degrees F., so keep them away from cold windows in winter.
Planting Instructions for Hoyas
Because the plants are adapted to life in the trees, their roots aren’t well suited to wet, heavy soils. To mimic their preferred conditions, choose a planter with plenty of drainage holes and fill it with a coarse potting mix that allows excess water to freely drain. For best results, look for potting mixes labeled for succulents, cactus, or orchids.
Choose a heavy pot to prevent the weighty vines from toppling the plant. Unglazed terra cotta is a good choice because the material is porous so water will evaporate, helping to prevent saturated soil that can lead to root rot.
Hoyas grow best when slightly rootbound. Newly purchased plants may not need repotting for several years. However, if you want to place your new plant in a more decorative container, choose one that’s the same size or just slightly larger than the original pot and set it at the same depth as it was in its original pot.
Fertilizer for Hoyas
Hoyas are relatively slow-growing and don’t need much supplemental fertilizer. A monthly feeding with an all-purpose houseplant fertilizer should suffice. Fertilize during active growth; stop fertilizing in winter when growth slows.
Hoya Pests and Problems
Hoyas are relatively pest-free, though they can be susceptible to the usual houseplant pests, such as aphids, scale, and mealybugs. Examine the plants regularly, including the undersides of the leaves, and treat affected plants with insecticidal soap if needed. A more common problem is yellowed leaves due to root rot caused by overwatering.
Ongoing Care for Hoyas
The most popular hoyas have succulent (fleshy) or semi-succulent leaves and, like other succulents, the plants require a light hand when watering. Moisten the soil mix and entire root ball, and then allow excess water to drain. Immediately empty water that has accumulated in saucers. Then wait to water again until the planting mix dries out completely. Most hoyas will slow growth or cease growing entirely in winter. During this time, water very sparingly and cease fertilizing.
Hoya plants send out long, shoot-like structures. Some of these are aerial roots that absorb moisture from the air and can cling to climbing surfaces. Others are shoots that, once they find a support to grab onto, will sprout leaves. Still others are flower stems, called peduncles or spurs, that are the sites of all flower production. Leave these structures in place. Never cut back the flower stem or remove spent blooms because that’s where the next flowers will appear.
Keep an eye on blooming plants; the flower nectar is so plentiful it can drip off the plants, so protect floors and/or other surfaces underneath.
