Black Spots on the Leaves of Variegated Swedish Ivy

Variegated Swedish ivy (Plectranthus forsteri), also known as green on green, characteristically has dark green leaves with lighter green accents around its edges. It may be grown in water, hanging baskets and planters.

Identification

• Black spots, particularly on older leaves, may indicate a problem with algae. If left untreated, the spots may completely cover the leaves.

Prevention/Solution

• Keep algae growth at bay by removing standing water on the leaves and reducing humidity around indoor plants, suggests University of Florida IFAS Extension. Do not let liquid fertilizer set on the leaf surfaces. Avoid planters that are clear or white, which tend to encourage the growth of algae around the plant's root system.

Considerations

• Common problems of variegated Swedish ivy include root rot---from inadequate drainage or overwatering---which may cause the plant to yellow and wilt. Pests include mealybugs and spider mites. Scale insects, which look like small brown disks, commonly attach themselves to the undersides leaves, along the veins.