Hoya

Light and exposure

The hoya wants plenty of light, but no scorching midday sun. The ideal spot here is an east-facing window or a bright place near a south-facing bay, screened by a light curtain during the hottest hours. Without enough light it survives but never flowers, and that is almost always the reason behind a hoya that stays tidy without ever producing its umbels.

During a Belgian winter, light is cruelly lacking from November to February. Move it closer to the brightest pane in the house during that period, even if it means shifting it from one room to another. A well-lit hoya develops thick, glossy foliage, while one starved of light grows long, floppy stems with wide gaps between the leaves.

Watering

This is where everything is decided. The hoya is a succulent: its fleshy leaves store water, and it far prefers dryness to excess. Water only when the substrate is thoroughly dry over several centimetres, then give it a good soak and let the water drain away completely. Always empty the saucer, a hoya left standing in water rots at the roots within a few days.

From autumn to early spring, space waterings out even more. In our low winter light and cool temperatures it drinks very little, and watering once every two or three weeks is plenty. Slightly wrinkled foliage signals genuine thirst and is quickly put right, whereas soft, yellowing leaves almost always betray overwatering, which is far harder to correct.

Soil and repotting

Since the hoya is an epiphyte, it hates heavy, compact potting soil that holds moisture. Give it a very free-draining mix: an indoor potting soil lightened by half with pine bark, a little perlite and a handful of clay pebbles. A substrate for orchids or for cacti and succulents also works very well, on its own or cut with potting soil.

A detail that often surprises: the hoya likes to be cramped in its pot. It flowers better with tight roots, so only repot it every two or three years, when it is truly overflowing. Choose a pot barely larger, in terracotta if possible, which lets the substrate breathe and dry out between waterings.

Temperature and humidity

The hoya is happy in the temperatures of a normal home, between 18 and 25 degrees, which suits it well since we keep it indoors all year. It tolerates a little coolness in winter, around 15 degrees, which even helps it prepare to flower, but never any lower.

In Belgium the real rule is simple: below 12 degrees it suffers, and the cold leaves lasting marks on its foliage. Do not put it out in the garden for the summer except during a genuine heatwave, and if you do, bring it back in well before the cool September nights. Also beware of cold draughts near a door and of direct contact with an icy pane in the depths of winter.

Pruning and upkeep

The hoya needs almost no pruning. You simply remove a damaged stem or shorten a vine that has become too invasive, cutting just above a pair of leaves. Its long bare stems that set off in search of a support are not a flaw, they will bear leaves and flowers, so guide them onto a hoop or a trellis rather than cutting them.

The golden rule, and the only truly serious mistake, concerns the flowering spurs. After blooming, the hoya leaves short, dry little stems where the flowers appeared, known as spurs. Never cut them: it reblooms exactly on them the following year, often in the same spot for years on end. Cutting these spurs means depriving yourself of the flowers to come, and it is the number one beginner’s mistake.

Pests and diseases

Indoors, the hoya is tough and rarely falls ill. The real danger remains overwatering, which causes rot in the roots and at the base of the stems. A hoya that yellows, goes soft and loses its leaves from the base almost always suffers from this, and the only way out is to take it out of the pot, cut away the black roots and repot it dry, or take a cutting from a healthy stem.

As for pests, watch out for mealybugs, those small white cottony clusters tucked into the leaf axils and on the stems, encouraged by the dry air of our heated homes in winter. Remove them with a cotton bud soaked in alcohol and repeat every week until they are gone. Spider mites can also appear in very dry conditions, and foliage rinsed off now and then keeps them at bay.

Propagation

The hoya roots from cuttings with disarming ease, it is the best way to share it. Cut a section of stem bearing two or three pairs of leaves, including a small node if possible, since that is where the roots will emerge. Let the cut dry for a few hours, then plant in a barely moist, free-draining substrate, or place the cutting in a glass of water.

Rooting takes a few weeks and works best in warmth, between March and September when the light returns. Once the roots are well formed, repot into a small pot and treat the cutting like an adult. Be patient though: a young hoya often takes two to three years before flowering for the first time, the time it needs to settle in.

Month-by-month care calendar

Green Hub tips

• Never cut the small dry spurs left by faded flowers: the hoya reblooms exactly on them each year, often in the same spot for a long time.
• Keep it cramped in its pot. With tight roots it flowers far better, so repot as rarely as possible.
• When in doubt about watering, wait. The hoya forgives a missed watering but rarely an excess, which makes it rot fast.
• A hoya that grows without flowering almost always lacks light: give it the brightest spot in the house.
• To multiply it, take a two-node cutting in spring in a glass of water or a free-draining substrate, it works every time.