Philodendron subhastatum (Subhastatum) care

Light

Bright but filtered. Philodendron subhastatum burns within days in unfiltered south-facing summer sun, and stops growing within months in deep shade. Bright, indirect light keeps growth vigorous and deepens the red underside colour. Tolerates medium light with slower, leggier growth. Protect from direct midday sun, which scorches the glossy leaves. If you only have a south window, set the plant back 1.5 m or hang a sheer curtain — both knock the intensity down into the right range.

Watering

Watering philodendron subhastatum: when the top 2-3 cm of soil is dry, roughly every 7-10 days. The number that matters isn't the day of the week — it's how dry the top 2-3 cm of the pot feels. A finger in the soil tells you more than a watering app. After every watering, tip the saucer. Water thoroughly, then let the top third of the mix dry before watering again. Consistent overwatering yellows leaves and rots roots; this climber tolerates brief dryness better than soggy soil.

Soil and pot

Philodendron subhastatum grows best in chunky, well-draining aroid mix. Use orchid bark, perlite and coco coir with some potting soil for aeration and steady moisture. Provide a moss pole or totem so it can climb and develop its larger, more colourful mature leaves. A pot with a working drainage hole is non-negotiable for this species — even free-draining mix will turn soggy in a closed planter. If you love the look of a decorative pot without a hole, use it as a cachepot around an inner nursery pot you can lift out to water.

Humidity and temperature

Philodendron subhastatum sits happiest at around 50-70% humidity and 18-29°C (65-85°F). Adapts to average household humidity around 40-50% but does best above 60%, which yields larger leaves and richer underside colour with fewer brown edges. If you keep the room above 18 year-round and avoid placing the plant near a cold draught, a hot radiator, or an air-conditioning vent, you have already handled the two biggest indoor stressors.

Fertilising

Feed philodendron subhastatum sparingly. Feed monthly in spring and summer with a balanced liquid fertiliser at half strength to support its fast climbing growth. Reduce in autumn and pause in winter. Flush the soil occasionally to clear accumulated fertiliser salts. Skip fertiliser entirely on a stressed, recently-repotted, or actively wilting plant — fertiliser salts make damage worse, not better. Wait for a round of healthy new growth before resuming a feeding rhythm.

Common problems

Below are the issues we see most often on philodendron subhastatum in the Growli community. Each is annotated with the most common cause so you know where to start.

• Faded red undersides — Too little light mutes the maroon colour. Provide brighter indirect light to restore the bicolour contrast.
• Yellowing leaves — Overwatering or poor drainage. Let the top third of the mix dry and ensure the pot drains freely.
• Leggy growth — Insufficient light or no support. Give bright indirect light and a moss pole to climb for fuller, larger leaves.
• Brown leaf tips — Low humidity or salt buildup. Raise humidity above 60% and flush the soil periodically.

Propagation

Propagate from stem cuttings with at least one node, ideally including an aerial root. Root in water, sphagnum moss or a chunky aroid mix in warm, humid conditions; roots typically form within two to four weeks. Propagation is the cheapest, most satisfying way to expand a collection — and it doubles as insurance against losing a mature plant to an accident. Take a backup cutting once the parent is established and healthy.

Toxicity to pets

Philodendron subhastatum is toxic to pets. Toxic to cats and dogs. The ASPCA lists Philodendron as toxic; like all Philodendron species it contains insoluble calcium oxalate crystals. Ingestion causes oral burning and irritation, excessive drooling, vomiting and difficulty swallowing. Keep out of reach of pets and children. If you keep cats, dogs, or curious children in the house, weigh placement carefully — a high shelf or a hanging planter is enough for casual safety. For severe ingestion incidents, call your local vet and the ASPCA Animal Poison Control Center (in the US, 888-426-4435).

Pet-safety status is sourced from the ASPCA Toxic and Non-Toxic Plant List, which catalogues the most-asked-about plants for cats, dogs, and horses.

Philodendron subhastatum deep-dive guides

Every aspect of philodendron subhastatum care, each with its own calibrated guide:

• Philodendron subhastatum watering schedule
• Philodendron subhastatum light requirements
• Best soil mix for philodendron subhastatum
• Philodendron subhastatum fertilizing guide
• When to repot philodendron subhastatum
• How to propagate philodendron subhastatum
• Philodendron subhastatum growth rate & size
• Philodendron subhastatum cold hardiness
• Philodendron subhastatum temperature & humidity
• Is philodendron subhastatum toxic to cats & dogs?
• Is philodendron subhastatum toxic to cats?
• Is philodendron subhastatum toxic to dogs?

Featured in these plant shortlists

Philodendron subhastatum qualifies for 6 curated Growli shortlists — each one filtered objectively from our structured plant-care library, so the selection is consistent and checkable:

• Best plants for a north-facing window — Houseplants for a north-facing window: bright, even, indirect light and no scorching direct sun. Each pick verified against its documented light needs.
• Best trailing & climbing houseplants — Vining and trailing houseplants for shelves, hanging pots, and moss poles — selected by growth habit.
• Best humidity-loving houseplants — Houseplants that thrive in a bathroom, kitchen, or by a humidifier — selected by documented humidity preference.
• Houseplants toxic to cats & dogs — The common houseplants the ASPCA lists as toxic to cats and dogs — the ones to keep out of reach, each with its symptoms and a safe alternative.
• Best houseplants to propagate in water — Houseplants that root from a cutting in a glass of water — the easiest, cheapest way to turn one plant into many.
• Best fast-growing houseplants — Houseplants documented as fast or vigorous growers — quick to fill a pot, cover a pole or trail down a shelf.
• Browse all 29 plant shortlists — pet-safe, low-light, drought-tolerant and more

Related guides

Philodendron subhastatum is also commonly called Subhastatum or Red-Back Philodendron.

• Types of philodendron — varieties identified, with care and pet-safety
• Snake plant care — light, water and common problems
• Dracaena care — light, water and common problems
• Peperomia care — light, water and common problems
• All 2464 plant care guides in the Growli library