Philodendron hederaceum aka Heart Leaf Philodendron

Philodendron hederaceum is a fast-growing perennial vine. NC State Extension lists mature dimensions of roughly 4 inches to 6 feet tall and 6 inches to 6 feet wide, with vining stems that cascade or climb depending on support. With a moss pole or trellis, indoor stems can reach 3–6 m (10–20 ft) over time, while plants grown as hanging baskets stay more compact. Growth rate is described as rapid in good conditions.

The heartleaf philodendron is one of the more shade-tolerant aroids. Clemson HGIC recommends indirect or curtain-filtered sunlight and notes the heartleaf form is "particularly shade-tolerant," while NC State Extension places it in deep shade to partial shade (less than 2 to about 6 hours of direct sun). Wikipedia adds that the plant survives at lower light levels than most houseplants, though it grows fastest with bright indirect light. Avoid prolonged direct sun, which can scorch the leaves.

Heartleaf philodendron is a tropical plant with a minimum tolerable temperature of about 15°C (59°F) according to Wikipedia, and it thrives in the 15–18°C range overnight up to typical daytime room temperatures. Clemson HGIC lists ideal indoor conditions of 65–70°F at night and 75–85°F during the day. It is not frost hardy and should be kept away from cold drafts and windows in winter.

Flowering is rare on indoor plants. According to Wikipedia, mature specimens occasionally produce a white aroid inflorescence — a spathe enclosing a spadix — but typically only after around 15 years of growth. In the wild, fertilized flowers develop into berries that ripen orange, red, or white.

Three botanical varieties are recognized: P. hederaceum var. hederaceum, the velvet-leaved form often sold under the trade name "Philodendron micans"; var. oxycardium, the standard glossy green heartleaf seen in most homes; and the rarer var. kirkbridei. Older horticultural names you may still encounter — including Philodendron scandens, P. oxycardium, P. cordatum and P. cuspidatum — are all considered synonyms of P. hederaceum.

Outdoors, P. hederaceum is restricted to frost-free climates. NC State Extension lists it as hardy only in USDA zones 11a–12b, and Wikipedia confirms a minimum temperature of about 15°C (59°F), so in cooler regions it must be grown indoors or moved into a heated greenhouse for the winter. In tropical and subtropical gardens it climbs trees and trellises happily as a semi-epiphyte.

The plant tolerates pruning well — Clemson HGIC describes philodendrons as adaptable houseplants and recommends removing leggy or damaged stems with stem cuttings, which can be rooted to propagate new plants. Trim above a node to encourage branching.

Clemson HGIC notes that overcrowded plants can be repotted in any season using general-purpose potting soil. The species is not particularly picky about pot size and grows well slightly root-bound, so repotting every couple of years is generally sufficient.

Propagation is straightforward. Wikipedia recommends taking stem cuttings or layering in spring and summer, cutting just beneath an axillary bud and rooting either in soil or in water with a small piece of activated charcoal kept in bright indirect light. NC State Extension and Clemson HGIC also list stem cuttings (and air layering) as the standard methods.

NC State Extension and Clemson HGIC both flag overwatering — and the resulting root rot in soggy soil — as the most common cause of foliar problems on heartleaf philodendron. Yellowing leaves frequently follow waterlogged roots, although insufficient light or nutrient imbalance can also contribute.

Clemson HGIC notes that excessive fertilizer can cause leaf-tip browning on philodendrons. Brown leaf edges or tips can also follow very dry indoor air, despite the plant's general tolerance of low humidity.

Although NC State Extension rates P. hederaceum as a rapid grower under good conditions, Clemson HGIC points out that low light, cold temperatures, and root rot from overwatering are typical reasons growth stalls indoors.

NC State Extension and Clemson HGIC list the same pest profile: spider mites, mealybugs, scale, and aphids are the most common insect issues, and root rot is the main disease, almost always brought on by overwatering or poor drainage.

In its native range Philodendron is beetle-pollinated, with scarabs in the genera Cyclocephala and Erioscelis acting as the principal pollinators. The leaf-like spathe traps the beetles around the spadix overnight while pollen transfer occurs.

P. hederaceum is grown almost exclusively as an ornamental houseplant. Wikipedia notes that it is particularly effective at removing formaldehyde from indoor air, and it has been awarded the Royal Horticultural Society's Award of Garden Merit for its reliability and beauty as an indoor specimen.