This epiphytic Philodendron is famously known for its large, split, hole filled foliage. Popularly grown indoors as a houseplant, this Philodendron loves humidity and can be encouraged to grow air roots and climb a trellis or moss pole with higher humidity. Leaf size and size of holes is correlated to the amount of sunlight the plant will have throughout the day. New foliage often has matte finish. Some cultivars have smaller holes, shinier foliage, or thicker stems. Known as a trailing / climbing sister plant to the famous Split Leaf Monstera.
Philodendon Adansonii, similar to most Pothos and other Philodendrons, are happy with 2 - 5 hours of direct sunlight, and a bright environment the rest of the day. Try supplementing with grow lights if new growth is progressively smaller with less holes. Philodendrons like humidity, so either misting with a spray bottle, keeping it near a humidifier, or at the very least near a bathroom, dishwasher, or other water source will encourage new healthy growth and should result in the development of air roots.
It is possible to grow Philodendron Adansonii aquatically. After taking cuttings from your main plant, root them in water, and leave them submerged with regular water changes. This will result in a smaller plant, with slower growth. If grown in soil with a trellis or pole, Adansonii are able to climb 10' +, but you can easily expect a 4' plant in your home. Single plants grown in the rainforest can easily grow to dozens of feet, given the appropriate growing conditions.
Fertilize systemically with Schultz All Purpose from March - October, every watering - every other watering.