Yellow Leaves
Yellowing leaves (chlorosis) are the most common houseplant distress signal. The pattern and location of the yellowing point to the cause.
Common causes
Overwatering
Soggy soil suffocates roots, so lower leaves yellow and feel soft. Let the top few centimetres dry out and check the pot drains freely.
Underwatering
If yellowing leaves are also crispy and the soil is bone dry, the plant is thirsty. Water thoroughly until it runs from the drainage hole.
Too little light
Plants far from a window shed lower leaves they can no longer support. Move it somewhere brighter (but not into harsh direct sun).
Nutrient deficiency
Uniform yellowing with green veins can mean a lack of nitrogen or iron. Feed with a balanced fertiliser during the growing season.