Wax plant vs Heartleaf philodendron

Hoya carnosa · Philodendron hederaceum

Pet safety: Wax plant is listed non-toxic to cats and dogs; Heartleaf philodendron is toxic (insoluble calcium oxalates). If the two are sold under the same name, a mislabelled plant is a genuine risk in a house with animals.

Why these two get mixed up

Heartleaf philodendron is recorded here as a pet-safe alternative to Wax plant, so the question is usually whether the swap is actually a fair one.

Wax plant (Hoya carnosa) — **Wax plant** — Hoya carnosa. Photograph by Yvan leduc, Wikimedia Commons , CC BY-SA 3.0.

Heartleaf philodendron (Philodendron hederaceum) — **Heartleaf philodendron** — Philodendron hederaceum. Photograph by KENPEI, Wikimedia Commons , CC BY-SA 3.0.

	Wax plant	Heartleaf philodendron
Scientific name	Hoya carnosa	Philodendron hederaceum
Family	Apocynaceae	Araceae
Light floor	Medium	Low
Water	10–18 days	7–12 days
Humidity floor	40%	40%
Mature height	12–144 in	6–120 in
Habit	trailing	trailing
Growth rate	moderate	fast
Difficulty	Easy	Easy
Toxic to pets	No	Yes
Typical price	$15–60	$10–30

Highlighted cells are where the two actually differ. Everything else they share.

The differences that matter

Pet safety

This is the difference that matters most. Wax plant is listed non-toxic to cats and dogs; Heartleaf philodendron is toxic (insoluble calcium oxalates). If the two are sold under the same name, a mislabelled plant is a genuine risk in a house with animals.

Mature size

Wax plant reaches about 144 inches; Heartleaf philodendron tops out near 120. Buying the wrong one for a shelf means rehoming it in a year.

Light

Heartleaf philodendron tolerates low light; Wax plant needs medium as a floor. Put the second in the first's spot and it stretches and declines.

Watering

Heartleaf philodendron wants water every 7–12 days, Wax plant every 10–18. On one shared watering schedule, one of them drowns.

Not even related

Wax plant is Apocynaceae, Heartleaf philodendron is Araceae. They share a shop label and nothing else — different families, different continents, different care.

Which should you buy?

With a cat or dog in the house, take Wax plant. The other is toxic, and if the shop label is wrong you will not know which you have brought home.
In a dim room, take Heartleaf philodendron.
If you forget to water, take Wax plant, which goes 14 days between drinks.
If it is your first plant, take Heartleaf philodendron, at 1 of 5.
For a small shelf, take Heartleaf philodendron, which stops around 120 inches.

Full entries

Wax plant — care fields with sources, toxicity with every authority consulted, propagation and diagnosis. Heartleaf philodendron — the same.

Sources

This database's own care records for Hoya carnosa and Philodendron hederaceum — every figure compared above.
Royal Botanic Gardens Kew, Plants of the World Online — accepted names and families for Hoya carnosa and Philodendron hederaceum
ASPCA Animal Poison Control — toxicity classification for both, cited on each species entry
Photographs: Wikimedia Commons, individually credited and licensed above

Compiled and edited by Tony Valcarcel · 2026-09-12
Every comparison above is drawn from a recorded field. Where the honest distinguisher is visual we show both photographs rather than describing a leaf we have no field for. How this is sourced.