Hoya pubicalyx
Hoya pubicalyx · the Wax Plant
It climbs the warm, humid rainforests of the Philippines as a fast, silver-flecked vine. Its real party trick is the flowers: clusters of waxy, star-shaped stars that look injection-moulded and turn on their scent at night.
Family
Apocynaceae
Origin
Philippines
In the wild
Climbs to 3 m
Indoors
2–3 m vine
Growth
Fast
With pets
Safe
Where it's from
The Philippines
Philippine rainforest
Often described as endemic to the Philippines, in humid lowland forest.
On a coin
A Hoya pubicalyx flower is depicted on the Philippine five-centavo coin.
Outdoors: zones 10–11
True tropical. Frost kills it, so it is a houseplant everywhere colder.
Never cut the spur
Hoyas bloom from a short woody stalk called a spur, or peduncle, and they rebloom from that same spur season after season. Once the flowers fade the spur looks bare and tempting to tidy away. Cut it off and you have removed next year's flowers. Leave it alone and it will bloom again from the same spot for years.
Porcelain stars
Each umbel holds about 25 to 30 tiny waxy five-pointed flowers with a glossy finish.
Scented at night
In the evening the whole cluster releases a strong sweet scent and can drip nectar.
Propagate from a node
Take cuttings from a vine node, never from the flower spur.
How to keep it
LightBright, indirect
A little gentle morning sun deepens leaf colour and blooming. Harsh midday sun scorches it.
WaterWhen the top 5 cm dries
The succulent leaves store water, so let it dry between waterings. Soggy mix is the main killer.
HumidityModerate to highPrefers around 60 to 70%, but tolerates average household air better than fussier hoyas.
Temperature16–24°CKeep above about 10°C. No frost, no cold drafts.
SoilChunky epiphyte mixOrchid bark, perlite and a little coir. Never dense, water-retentive potting soil.
FeedingGrowing season onlyA dilute balanced feed in growth. A higher-potassium feed can encourage flowering.
DifficultyEasyOne of the quickest-growing and most tolerant hoyas. Many people's first hoya.
With petsSafeNon-toxic to cats, dogs and horses. The cut stems exude a milky latex that can irritate skin.
PropagationCutting at a nodeStem cuttings with a node or two root in a few weeks. Never cut off the flower spur.
RepottingEvery 2–3 yearsIt blooms best slightly pot-bound. Move up only one pot size when rootbound.
What the data says
What it costs
A cheap, mass-propagated beginner hoya. Cuttings strike easily, so it spreads through the trade.
$10–25
Sought-after named cultivars like Royal Hawaiian Purple run higher, roughly $30 to $60 and up.
IUCN · Not assessed
In the wild
Abundant in cultivation, while its native lowland forests keep shrinking.
Hoya pubicalyx has no published Red List assessment and the genus is not CITES-listed. Cultivation has vastly outstripped any wild population. The broad pressure is lowland rainforest loss in the Philippines from logging, agriculture and development. A gentle version of the houseplant paradox: thriving in our homes, its habitat quietly disappearing.
When it sulks
No flowersNot enough light, too young, repotted too often, or the bloom spur was cut off.
Yellowing leavesRoot rot from overwatering or a dense, slow-draining mix.
Shrivelled, wrinkled leavesUnderwatered, or root-damaged, so the leaves draw down their water store.
Dropped budsMoving the plant, cold drafts, or letting it dry out while budding.
PestsMealybugs hide in the leaf axils and new growth. Also aphids, scale and spider mites.
Varieties & company
The varieties
SplashPink SilverRoyal Hawaiian PurpleRed ButtonsBlack Dragon
Pairs with · keep apart from
Other HoyasString of HeartsRhipsalisFernsCalatheaPeace Lily
A new plant, every week.
The Data Drop from Sheets Works. New field guides like this one, in your inbox.
