Habitat:
Dieffenbachia grayumiana is endemic to Costa Rica, where it grows in lowland to premontane rainforests on the Caribbean slope, particularly in the Limón and Heredia provinces. It occurs at elevations from 100 to 600 metres, typically in humid tropical forest understory where light is diffuse and conditions are consistently moist and warm. It grows terrestrially in rich organic soils, often near streams or in areas with frequent leaf litter accumulation.
Description:
This herbaceous aroid reaches up to 1.5 metres tall, with erect, cane-like stems that may branch at the base. The leaves are large, elliptic to oblanceolate, measuring 30–50 cm in length and 10–20 cm in width, with a deep green ground colour heavily marked with pale cream or yellowish speckling and blotching, especially along the midrib and secondary veins. The petioles are winged and slightly sheathed at the base. Inflorescences are typically held close to the stem and consist of a short greenish-white spathe, about 10–12 cm long, enclosing a yellowish spadix. Male and female flowers are separated on the spadix, as in all Araceae. Fruiting is rare in cultivation, with berries turning orange-red when mature.
Cultivation:
Grow Dieffenbachia grayumiana in moderate, indirect light with no direct sun exposure. Ideal daytime temperatures range from 20–28 °C, with nighttime lows around 16–18 °C. Keep humidity levels at 60% or higher. Soil should be rich, loose, and moisture-retentive, such as a mix of peat, perlite, and fine bark. Maintain a slightly acidic to neutral pH (5.8–6.5). Water regularly to keep the soil lightly moist but avoid saturation. Fertilise monthly during the growing season with a balanced houseplant feed. Protect from cold drafts and avoid disturbance to the roots when repotting.
Specifications:
Plant Size: Established plants at least 30 cm tall. Growing in pots.
Plant Family: Araceae
Plant Passport: Dieffenbachia grayumiana B 140084 C [user input] D GB