Why are my shrubs leaves turning yellow?
Iron deficiency may be the problem. Iron is required for essential chlorophyll production in plants. Iron deficiency can result from an imbalance of other nutrients such as Mo, Cu, or Mn. Other factors that may cause iron deficiency are excessive phosphorus in the soil, and a combination of high pH, high bicarbonate levels, high lime, and wet and cold soils.
Yellowing of leaves may also be caused by:
• Sucking insect damage
• Individual leaves reaching end of life cycle
• Air pollution, vehicle exhaust
• Soil pH out of range
• Poor drainage, roots drowning (also wilting)
• Lack of fertilizer
• Improper light needs
Contact your local Extension office and inquire about plant diagnostic services. It is important to get the problem properly identified before taking corrective measures.