The most common cause of yellowing leaves among Money Trees is improper soil moisture–in particular, overwatering. Your Money Tree prefers deep but infrequent watering.
When you water your Money Tree, make sure you provide enough water so that liquid flows from the drainage hole at the bottom of the pot and into the saucer. It’s extremely important to discard any excess water in the saucer and not to let your plant sit in any standing water. Money Trees don’t like “wet feet,” which will cause the roots to rot and lead to the eventual death of the plant. Yellow and browning leaves are the first sign that root rot may be occurring.
Your humidity level
Low humidity and dry soil cause leaves to droop and brown on their edges, later followed by entire yellowing, browning, and shedding. Your Money Tree will appreciate a boost in humidity from regular misting, a humidifier, or pebble tray.
Your Money Tree will grow best when placed in bright indirect sunlight, but it will tolerate medium light. When exposed to direct sunlight for too long, the foliage will burn. Your Money Tree can adapt to low light areas, their growth may slow. If placed in very low light, yellow leaves may develop.
A weakened or stressed Money Tree is 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 Money Tree is already unhealthy from poor lighting, a nutrient deficiency or improper soil moisture.
Some yellowing is natural
Is your Money Tree producing new growth? 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.