Watering
Your Monstera Peru likes to dry out a little between waterings. Be sure the soil is never soggy as they don’t like “wet feet”. Water when 50-75% of the soil volume is dry. Water thoroughly until it flows out of the drainage hole and discard the excess water.
Lighting
Too much light can cause your plant’s leaves to appear bleached out and crispy. Too little light can cause a lack of chlorophyll, which your plant needs for photosynthesis. Monstera Perus perfect indirect light. Bright indirect light can be found in places close to an east-facing window or a few feet back from an unobstructed southern or western window. If the southern or western window has something like a sheer curtain, natural shade from a tree or building outside, the plant can be placed a little closer.
Pests
Weakened or stressed plants become more susceptible to insect infestations. Sap-sucking bugs like spider mites can drain your plant of moisture. This problem quickly manifests itself by yellowing leaflets and fronds. Scale, mealybugs, and spider mites occur frequently in indoor conditions. If not killed early on, these small pests proliferate and move all along frond parts into nooks and crannies. The piercing mouths of the insects exhaust your plant and accelerate yellowing, especially if your plant is already unhealthy from poor lighting, a nutrient deficiency or improper soil moisture.
Natural Life Cycle
If there is new growth on your plant and the yellowing leaves are older, particularly at the bottom of the plant, this yellowing is natural. Your plant sheds its old leaves and sends energy to new growth! You can simply trim any old leaves off to help your plant focus its energy on new and healthy growth.
