Philodendron Selloum

How to care for Philodendron Selloum

Light

Thaumatophyllum bipinnatifidum thrives in bright, indirect light and will produce its largest, most deeply lobed leaves under these conditions. It tolerates lower light levels better than many large-leaved aroids, though growth slows noticeably and leaves may become smaller and less incised. Direct summer sun through glass can scorch the leaves, so filter strong rays with a sheer blind or position the plant a metre or so back from a south-facing window.

Watering

Water thoroughly when the top 5 cm of compost has dried out, allowing excess to drain freely from the pot. Overwatering is the most common cause of decline; the thick rhizomatous stem and roots are prone to rot if kept consistently wet. Reduce watering frequency in autumn and winter when growth slows, but never allow the compost to dry out completely for extended periods.

Soil and potting

A well-aerated, free-draining aroid mix is ideal. A suitable home blend consists of peat-free compost combined with perlite and bark chips in roughly equal proportions to ensure good drainage and aeration around the roots. Avoid dense, water-retentive composts such as standard multi-purpose mixes used on their own, as these hold too much moisture around the roots.

Feeding

Apply a balanced liquid fertiliser diluted to half the recommended strength once a month throughout the growing season from spring to late summer. Feeding is not necessary during autumn and winter when growth is minimal. Over-feeding can cause salt build-up in the compost, leading to tip burn; if this occurs, flush the pot thoroughly with plain water.

Humidity and temperature

This plant prefers humidity of 50% or above, which helps maintain the vigour and size of its leaves. In centrally heated homes, a pebble tray filled with water, regular misting or a nearby humidifier will all help. Keep temperatures between 18 and 29 C for best growth; the plant will tolerate a minimum of around 13 C but growth ceases below 15 C and prolonged cold can cause significant damage. Avoid cold draughts and sudden temperature fluctuations.

Repotting

Repot every two to three years or when roots visibly emerge from the drainage holes and the plant becomes pot-bound. Choose a pot only one to two sizes larger than the current container; excessively large pots hold surplus moisture and increase the risk of root rot. Spring is the best time to repot. As the plant matures it develops a thickening above-ground stem and aerial roots, both of which are normal and should not be removed.

Pruning

Pruning requirements are minimal. Remove yellowing or damaged leaves at the base of the petiole using clean, sharp scissors or secateurs to maintain appearance and prevent the spread of disease. Wear gloves when handling cut stems, as the sap contains calcium oxalate crystals that cause skin irritation. Periodically wiping the large leaf surfaces with a damp cloth removes dust and improves the plant's ability to photosynthesise.

Is Philodendron Selloum toxic?

Common problems

How to propagate

Stem cuttings

Take a cutting with at least one node and one leaf, allow the cut end to callous for an hour or two and then place it in moist perlite or water until roots form over four to eight weeks. Maintain warmth above 20 C and indirect light for best results.

Division

When repotting, separate offsets or basal suckers that have developed their own root system from the parent plant using a clean, sharp knife and pot each division individually into a suitable aroid mix.

Seed

Fresh seed can be sown on the surface of moist, well-draining compost at around 25 C; germination typically takes two to four weeks but seed viability drops quickly and commercially available seed is often unreliable, making this a slow method rarely used in cultivation.

Where Philodendron Selloum comes from

Native to southern Brazil, Paraguay, Argentina, Bolivia.

Story and origins

The genus name Thaumatophyllum is derived from the ancient Greek 'thauma' meaning wonder or miracle, and 'phyllon' meaning leaf, a reference to the remarkable size and form of the foliage. The species epithet bipinnatifidum is Latin, meaning twice-pinnately cleft, describing the deeply and repeatedly divided lobes of the mature leaf blade. The long-used synonym selloum, now reduced to a trade name, is thought to have honoured Friedrich Sello (also written Sellow), a Prussian botanist and plant collector who gathered specimens in Brazil during the early nineteenth century.

Thaumatophyllum bipinnatifidum was first formally described by the German botanist Heinrich Wilhelm Schott in 1856, drawing on specimens collected in Brazil, Argentina and surrounding countries. Schott was one of the foremost aroid specialists of the nineteenth century, describing hundreds of species in the family Araceae. The plant became widely cultivated as an ornamental during the twentieth century, particularly in tropical and subtropical gardens worldwide, and gained popularity as a houseplant in temperate countries from the 1970s onwards. Its bold foliage made it a signature plant of modernist interior design. It remains one of the most widely recognised large-leaved houseplants despite the 2018 reclassification into Thaumatophyllum, a change that has been slow to filter through the horticultural trade.

Varieties to know

Thaumatophyllum bipinnatifidum 'Hope'

A compact cultivar widely sold as 'Philodendron Hope'; reaches a more manageable size than the species and is a popular choice for indoor cultivation.

Thaumatophyllum bipinnatifidum 'Variegatum'

An uncommon form with irregular cream or yellow variegation on the leaves; slower growing and more difficult to cultivate than the straight species.

Thaumatophyllum bipinnatifidum 'Compactum'

A smaller-growing selection with a more upright habit, suited to indoor use where space is limited.

Fun facts

• The genus name Thaumatophyllum derives from the Greek words 'thauma' (wonder or marvel) and 'phyllon' (leaf), meaning 'marvel-leaved', in reference to the impressive foliage.
• In its native South American habitat, Thaumatophyllum bipinnatifidum can develop a trunk-like stem up to 1.5 metres tall and produce leaves exceeding 1.5 metres in length outdoors.
• The plant is a self-heading philodendron, meaning it grows upright from a central point rather than producing vining stems, which distinguishes it from climbing species such as Philodendron hederaceum.
• Mature plants can produce inflorescences typical of the Araceae family: a cream-coloured spathe surrounding a spadix, which generates its own heat through thermogenesis to volatilise scent compounds and attract insect pollinators.
• A major taxonomic revision published in 2018 in the journal Taxon moved this species and several relatives out of Philodendron and into the reinstated genus Thaumatophyllum, based on morphological and molecular evidence.

Philodendron Selloum FAQ