What Mineral Does a Clematis Need to Turn Leaves From Yellow to Green?

Nutrient Deficiency

• A number of nutrients are required in the soil for the healthy production of green leaves. A deficiency in any one nutrient may be enough to cause leaf yellowing. However, it is more likely the soil lacks variety of nutrients. Regular feeding with a balanced fertilizer helps keep leaves healthy. A soil test in the early spring determines what nutrients are low.

Nitrogen Deficiency

• Nitrogen, phosphorus and potassium are three essential nutrients for plant growth. Nitrogen is essential for the production of healthy green leaves. A lack of nitrogen in the soil leads to weak, yellow leaves and even premature leaf loss on the clematis plant. Adding a fertilizer containing nitrogen to the soil around the clematis restores the leaves to health and prevent defoliation. Applying fertilizer in the early spring avoids yellowing leaves.

Iron and Calcium

• Iron and calcium are minerals needed to produce dark-green leaves throughout the growing season. A lack of these nutrients in the soil leads to producing weak, yellow leaves. It often takes the form of chlorosis, which is yellowing between the veins of the leaves. Applying an iron- and calcium-containing fertilizer to the soil around the clematis plant restores these nutrients.

Other Causes of Yellowing

• Although nutrient mineral deficiencies are a common cause of yellowing leaves in clematis plants, there are other problems contributing to unhealthy leaves. If fertilizer was properly applied and the leaves remain yellow, check the plant for signs of disease, such as dieback of vines and branches or weak flower production. Look for pests on the undersides of leaves. Clematis plants grown in full sun are susceptible to scorch, which causes yellow leaves.