Wax plant

Sweetheart hoya / heart leaf

Thick heart-shaped leaves commonly sold as a potted 'single leaf' Valentine's plant. Much slower-growing, rarely vines or flowers.

Australian wax plant

Thinner, larger, more elliptical leaves; white flowers with a pink-red centre rather than solid pink. Native to northern Australia and Pacific islands.

String of nickels

Same family (Apocynaceae) but much smaller coin-shaped leaves on a trailing rather than twining vine. Flowers are tiny and inconspicuous.

Bright indirect; morning sun tolerated.

Place directly beside an east window, or within 1–2 m of a south/west window with filtered light. Strong direct midday sun bleaches the leaves yellow-white; deep shade prevents flowering. If the plant is healthy but not blooming after 2+ years, insufficient light is the most likely cause.

Seasonal: Nordic winters above ~55°N: a full-spectrum LED at 15,000 lux for 12 hours/day from October to March is the difference between a vine that blooms reliably every summer and one that never does.

When top 3–4 cm of soil is dry.

Water thoroughly until runoff, then empty the saucer and wait. The thick succulent leaves store weeks of water; Hoya is far more forgiving of underwatering than overwatering. Wrinkled leaves = thirsty; mushy leaves = root rot. A bright plant in active summer growth drinks roughly every 10–14 days; the same plant in winter may go 3–4 weeks between waterings.

Seasonal: Reduce to once every 3–4 weeks from November through February.

Chunky epiphytic mix.

A blend of 2 parts orchid bark, 1 part coco coir or peat-free potting soil, 1 part perlite, and a small handful of horticultural charcoal works well. Hoya are epiphytes — they grow attached to tree bark in nature, not in soil. A chunky airy mix that dries quickly around the roots matches that ecology.

40–60 %; tolerates lower.

Hoya carnosa is the most forgiving Hoya in dry air. Many other Hoya species (especially H. linearis) demand 60 %+ humidity; H. carnosa is happy in typical indoor air. Higher humidity accelerates growth and flowering spur formation but is not essential.

16–27 °C in active growth; brief cool winter rest at 13–15 °C helps flowering.

Brief exposure below 10 °C causes water-soaked spots on leaves. A modest cool winter rest (13–15 °C, reduced watering) encourages the following spring's flower flush. Keep away from radiators and cold window glass.

Balanced feed monthly in spring and summer at half strength.

A balanced NPK (e.g. 20-20-20) at half the label rate, applied to moist soil, is ample. Once flower spurs appear, switch to a high-phosphorus bloom-boosting feed (e.g. 10-30-20) to extend flowering.

Seasonal: Stop feeding from late October through February.

Minimal — do NOT cut old flower spurs.

Hoya flowers from short permanent spurs that re-bloom every year from the same point on the stem. Cutting the spur eliminates that year's (and future years') flowers — the single most common Hoya care mistake. Prune only for shape, and only cut stems with no flower spurs. Remove dead leaves by pulling sideways.

Every 3–4 years; prefers to be pot-bound.

Hoya flowers better and more reliably when pot-bound — a plant that has filled its pot with roots is far more likely to bloom than one just repotted into extra space. Only repot when roots emerge from the drainage hole or the soil has broken down. Use a pot only 2 cm wider than the previous.

No documented toxicity. The milky latex that emerges from cut stems can cause mild skin irritation in sensitive individuals; wash hands after pruning.

Not listed on ASPCA's toxic plant database. Ingestion of the waxy leaves may cause mild GI upset in sensitive animals but no systemic toxicity is recorded.

Not listed on ASPCA's toxic plant database. Mild GI upset is possible with any non-food plant ingestion but no systemic effects are recorded.