Since you are letting the soil dry out between waterings I'd say it was lack of nutrients. Specifically nitrogen.
Gen Reviewed by Gen on . What causes color change? It may be me but it looks as if some of the leaves are a greenish yeloow color, what can cause this and how often should you be watering your plants? i usually water them when the soil gets dry like a grayish color is this ok? :confused: :confused: :confused: :confused: GrowinGreen23 Rating: 5