Why are the leaves of my plumbago shrubs turning yellow?
Plumbago auriculata leaves can turn yellow and fall off for several reasons this time of year. First, check and see if the soil is saturated. Over-watering or poor drainage will cause root loss that results in yellowing leaves. I have noticed this on hillside plantings in southern California. Second, fertilize with a balanced fertilizer if over-watering is not the issue. Nitrogen in the fertilizer will provide the essential nutrients to help perk up the color of the foliage. Third, yellow leaves with dark green veins indicate a lack of available iron in the soil. Add an iron plant food supplement such as Ironite to the soil and water well. Finally, the plant could be sulking from excessive or reflected heat. If this is the case, the foliage will look better in the cooler fall months ahead.
