I’ve had a Hoya plant in the family for decades. My mother used to have it loaded with blooms at various times of year. Now, it hasn’t bloomed in years, save for one single bloom this past summer.
What can I do to encourage it to bloom more prolifically?
It is likely that you are growing Hoya carnosa, or wax plant. Of the nearly 300 different types, Hoya carnosa is the most commonly cultivated species- prized for its shiny thick, green leathery leaves that are sometimes flecked with silvery or creamy white and their sweet smelling star shaped flowers. Hoya are in the Asclepiad (milkweed) genus of the Dogbane family- native to Asia , Australia and Polynesia.
Like most tropical plants, your Hoya will do well when placed in a pot or hanging basket near a window where it can receive very bright, indirect light. Too much direct sunlight can cause the foliage to burn. According to the International Hoya Society (IHS), insufficient bright indirect sunlight is the most common reason that Hoyas don’t flower.
Water your plant regularly from spring through fall, allowing the top third or half of the soil to dry out completely between watering. The IHS recommend that for mature, non flowering Hoyas, try to fertilize weekly with a very weak solution of a balanced 20-20-20 liquid plant food- during the active growing season. Substitute this regular feeding with a high phosphorus fertilizer occasionally. (Phosphorus is the middle number ) Make sure to follow directions on the label.
Being a tropical species, Hoya carnosa love humidity – above 40% if possible, so mist with a spray water bottle three or four times a week. Misting replicates their natural environment in the understorey of rainforests. They often do well in bathrooms and kitchens where humidity tends to be higher.
Hoyas do not go dormant in the winter, however growth does slow down with the lower light levels. One of the few problems with Hoya plant care is overwatering. Allow the soil to dry out a bit between watering during the winter from October-February and stop fertilizing until spring.
Allow spent blooms to remain on the plant. New blooms emerge from the same area of the stem, or peduncle, as the old blooms.
Hoyas like the security of a snug pot, and plants that are a bit root bound will flower more often. For more information, the IHS have a lot of interesting facts in the FAQ section of their website. See link below. Good luck!