Nepenthes rajah is comparable to that experienced in nature, since Borneo lies on the equator. Pure long-fibre "Sphagnum" moss is an excellent potting medium, though combinations involving any of the following – peat, perlite, vermiculite, sand, lava rock, pumice, "Osmunda" fibre, orchid bark and horticultural charcoal – may be used with equal success. The potting medium should be well-drained and not too compacted. Moss is useful for moisture retention near the roots. The mix should be thoroughly soaked in water prior to potting the plant. It has been noted that "N. rajah" produces a very extensive root system (for a "Nepenthes") and,
Sphagnum fuscum a short stalk of around 1-2mm, with a brown capsule of about 1-1.5mm. "Sphagnum fuscum" prefers older, drier bogs to inhabit and will formulate hummocks in such conditions. In bogs dominated by black spruce, "S. fuscum" will form extensive ground cover. On average, "S. fuscum" inhabits more acidic soils with pH ranging from 3.6-7.5, and is also able to colonize at high elevations. The moss is circumpolar. "Sphagnum fuscum" faces endangerment across much of the globe. Due to reductions in wetlands and development of these areas, the moss is referred to as “high risk” in Germany, while being on several