Philodendron Rojo Congo

Rojo Congo is self heading rather than climbing, forming a broad rosette on a stout stem that lifts and leans as it ages. New leaves unfurl a deep red bronze and mature to thick, glossy dark green held on burgundy petioles, and those red stems are what separate it from Congo Green, which never shows the colour, and Imperial Red, which keeps a redder leaf on a shorter, tighter plant. It fills office foyers, shopping centre planters and shaded courtyards, wherever a broad evergreen mass is wanted at floor level.

Shade, mix and a light hand with water

Shade to part shade is where it belongs, and the red colouring comes through far more strongly in bright indirect light than in a dark corner, so pick the brightest shaded position you have rather than the darkest. Water is moderate, enough to keep the mix damp through the warm months and less in winter. The mix matters more than the schedule. Use a chunky, open, free draining blend with bark through it, in a pot with drainage holes, because overwatering in a dense mix is what kills these plants and the symptoms, yellowing lower leaves and a limp look, read like thirst and prompt more watering. Outdoors it needs a frost free garden and a genuinely sheltered position, under established trees or on a covered terrace, out of wind that tears the large leaves. Warmth matters as much as shade, and a cold draught from an air conditioning outlet marks the leaves faster than anything else in an office fitout. Grouping plants together lifts the humidity around them. The sap is an irritant and the leaves and stems carry calcium oxalate crystals, so wear gloves when dividing or cutting, and keep it out of reach of pets and small children who chew foliage.

Rojo Congo or a cycad in a pot

When the brief is a large pot that has to hold a courtyard, this and Cycas revoluta sit at opposite ends of the choice. The cycad is rigid, symmetrical and formal, and it takes far more sun and exposure; Rojo Congo is soft, broad and shade loving. Neither belongs in a household with animals that chew plants, because cycad seed and trunk tissue cause liver failure in dogs and philodendron foliage burns the mouth and throat. Indoors, Dracaena marginata is the vertical answer where this one is horizontal, and it wants more light and less water. Choose Rojo Congo for shaded floor level mass with colour in the new growth, and note that it holds its shape without staking. More options in indoor plants.

Leaves, gloves and repotting

There is no conventional pruning. Cut off lower leaves at the petiole as they yellow, which happens naturally as the stem lifts, and wipe dust off the foliage every few weeks so the leaves keep working and the gloss shows. A plant that has leaned too far can be cut back into the stem and will reshoot, or be taken off below the head and reset lower in the pot. Feed monthly at half strength through the warm months and stop over winter. Dividing is best done in warm weather, cutting through the base with a clean knife and potting each piece straight into fresh chunky mix. Repot every two to three years.

Choosing a size

This plant is available in 8 sizes, from 66mm Square up to 45L, priced from $16.95 to $229.00 per plant. The size shown is the pot the plant arrives in, which is the rootball, not the height of the plant. The smaller pots hold younger plants that cost less each and establish quickly, which suits hedges, screens and mass planting where the plant count adds up. The larger sizes carry several more years of growth on the farm and give height and presence straight away, which is what you want for a single feature position or a screen that cannot wait. Not sure which to choose? Read our guide to when to plant in Australia.