Houseplant

Hoya (Wax Plant)

Hoya carnosa · Apocynaceae

Also called: Wax Plant, Wax Flower, Porcelain Flower, Honey Plant

Hoya (Wax Plant) (Hoya carnosa) is a low-water houseplant well suited to Tucson and the low desert. It's a slow to moderate-growing houseplant.

Hoya (Wax Plant) (Hoya carnosa) growing in Tucson
Photo: Yvan leduc (CC BY-SA 3.0) · Wikimedia Commons

Hoya (Wax Plant) at a glance

Water use
Low (established)
Sun
Bright indirect light indoors; tolerates some gentle direct morning sun, which encourages blooming. Avoid scorching direct Tucson afternoon sun through glass.
Mature size
Vining to 4-8+ ft; train on a trellis or let trail from a hanging basket.
Growth rate
Slow to moderate
Bloom
Pink and white with red/pink centers, Late spring through summer once mature; produces rounded clusters (umbels) of star-shaped, waxy, fragrant flowers.
Cold hardiness
Frost-tender; keep above ~50 F indoors. Not winter-hardy outdoors in Tucson.
Soil
Chunky, very well-draining mix (potting soil with orchid bark/perlite); likes to be slightly root-bound.
Native range
Eastern Asia and Australia (India to southern China, southeast Asia, and Queensland)
Best used as
Indoor hanging basket, Trellised vining houseplant, Fragrant flowering accent, Bright-window specimen
Wildlife
Fragrant flowers attract pollinators if grown on a protected patio, but it is grown mainly indoors in Tucson.
Toxicity
Generally considered non-toxic to cats and dogs (not on ASPCA's toxic list); sap may cause mild skin irritation in sensitive people. A good pet-tolerant choice.

How to grow Hoya (Wax Plant) in Tucson & the low desert

Watering

Semi-succulent: water thoroughly, then let the top 1-2 inches dry before watering again, roughly every 1-2 weeks, less in winter. The thick waxy leaves store water, so it tolerates Tucson's dry indoor air well; overwatering causes leaf drop and root rot.

Fertilizer & nutrients

Feed monthly spring through summer with a dilute balanced liquid fertilizer; a higher-phosphorus bloom formula can promote flowering. Do not feed in winter.

Pruning & care

Minimal; do NOT remove the leafless flower spurs (peduncles), as new blooms form on the same spurs year after year. Trim only to shape or control length.

Notes

An easy, durable houseplant well-suited to Tucson interiors because its succulent leaves handle dry desert air and infrequent watering. Patience is needed: it blooms only when mature and slightly pot-bound, and the flowers drip sweet sticky nectar. Can summer on a shaded patio but must come indoors before frost.

Sources: University of Arizona Cooperative Extension; ASPCA Toxic and Non-Toxic Plant List; Missouri Botanical Garden Plant Finder

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