Philodendron McDowell Philodendron 'McDowell' (gloriosum × pastazanum) A hybrid of P. gloriosum and P. pastazanum combining the best of both terrestrial creepers — large, broadly heart-shaped leaves with a velvety surface and prominent, deeply impressed silvery-green to white venation that creates a bold ribbed texture. Larger than gloriosum and retaining the deep vein definition of both parents. A terrestrial rhizome creeper that spreads horizontally rather than climbing, best grown in a wide, shallow container. Light: Bright indirect light; avoid direct sun which scorches the velvety surface. Good light supports the largest leaves and most defined vein contrast. Soil: Chunky, well-draining aroid mix of orchid bark, perlite, and coco coir in a wide, shallow container; the rhizome should sit at or just above the soil surface. Temperature/Humidity: Warm temperatures between 65-80°F; humidity of 60-70% supports the best leaf quality and most prominent venation. Watering: Allow the top 2" of medium to dry between waterings; water thoroughly and drain completely. Sensitive to overwatering — never waterlog. Fertilizer: Feed with a balanced liquid fertilizer every 4 weeks during active growth; supplement with calcium and magnesium for best leaf quality. Reduce in winter.