Heartleaf philodendron

Identification and origin

Philodendron hederaceum belongs to the arum family, Araceae. Its native range covers Mexico, all of Central America, the Caribbean (Cuba, Hispaniola, Jamaica, Puerto Rico, the Lesser Antilles and Trinidad) and northern South America south to Peru, Bolivia and Brazil. Long sold as Philodendron scandens, P. oxycardium or P. micans, it now goes by this single name.

It is an evergreen herbaceous vine that trails or climbs, clinging with aerial roots that form along its slender green stems. In the wild it can reach 13 ft; in a pot, its stems often grow beyond 4 ft. The leaves are alternate, heart-shaped, smooth, glossy and slightly leathery, 2–6 in long indoors; outdoors in warm climates they can exceed 12 in. They emerge bronze and quickly turn green; the undersides are green or reddish purple.

How do you tell it from pothos, its frequent look-alike? The philodendron’s leaf stalk has no groove, while the pothos’s does. Each new philodendron leaf emerges wrapped in a sheath (stipule) that dries and drops off; pothos has none. Its leaves are also thinner and softer. Cultivars include ‘Brasil’, with a yellow to light green central stripe; ‘Lemon Lime’, bright chartreuse; and ‘Rio’, variegated with silver and cream. It rarely flowers in cultivation.

Light

It prefers medium to bright indirect light: near a north-, east- or west-facing window, or under artificial light. Its great strength is surviving for long periods in very low light, which makes it a good choice for dim rooms. Do keep it out of direct sun, though, which damages the foliage.

Watering

The rule: mix that stays lightly and evenly moist, never soggy. Water when the top 1–1 in feel dry, and never let the pot sit in a full saucer. In winter, when growth slows, water less often. A plant that is slightly pot-bound dries out faster between waterings, which lowers the risk of overwatering.

What to watch for: yellowing lower leaves and dying stem tips usually mean too much water, or too little light.

It grows best in high humidity and appreciates misting, but copes well with dry indoor air, even in winter.

Potting mix

An all-purpose indoor potting mix, lightweight and well-drained, that holds a little moisture. During the growing season, a diluted water-soluble fertilizer for foliage plants keeps it vigorous; too much fertilizer makes leaf tips turn brown and curl.

Temperature

Normal home temperatures suit it: ideally 64–81 °F, with days of 70–84 °F and nights of 64–75 °F. Below 50 °F is too cold for it. Planted in the ground year-round, it only grows in tropical climates (USDA zones 11 and 12), where it is used as a groundcover or climbing vine.

Repotting

Move it to a pot one size larger when it is truly crowded or when the mix dries so fast you cannot keep up with watering. It can be repotted in any season, using all-purpose potting mix.

Pruning

It needs no regular pruning. If some stems grow too long, you can cut them back: the pieces you remove make excellent cuttings. Aerial roots can be left alone, trained onto a support so the plant climbs, or snipped off close to the stem with clean pruners. The sap may irritate skin, so wear gloves if you are sensitive.

Propagation

It is one of the easiest plants to grow from cuttings, in any season. Take stem sections 3–6 in long, remove the lower leaves and set them in water, perlite or a well-drained potting mix. They root readily; once the roots are well formed, pot them up in fresh mix.

Common problems

• Yellow leaves: overwatering or too little light.
• Brown, curled leaf tips: too much fertilizer.
• Pests: aphids, mealybugs, scale insects and spider mites.
• Diseases: leaf spots; root rot in mix that stays too wet.

Overall it has no serious problems. Keep in mind that the same symptom can have several causes: check watering, light and feeding before you act.

Toxicity

Toxic to dogs, cats and horses, and to people. All parts contain insoluble calcium oxalate crystals. Chewing them causes irritation, pain and swelling of the mouth, tongue and lips, excessive drooling, vomiting (except in horses) and difficulty swallowing; in pets the swelling can be moderate to severe. In people, toxicity is considered low, but contact with the sap can cause a mild skin rash. Hang it out of reach of children and pets, and if any is swallowed, call a veterinarian or Poison Control.