What Is Wrong With My Four O' Clock Flowers?

Are there any small, necrotic flecks on leaves that develop a chlorotic halo and expand into tan brown necrotic spots?

Are there any yellow and wilting leaves, brown streaks appear on a lower surface of leaves, the growth is stunted?

Are the leaves yellowing, wilting and, dying?

Are the leaves pale on their upper side and are there any dusty blisters on the undersides?

Are the leaves curled and distorted?

Do the leaves have large, ragged holes in them?

Cercospora leaf blight is caused by a fungus that can be introduced through infected seed and spread by wind or water splash. Plant only pathogen-free seed from a reputable nursery. Apply copper-based foliar fungicide if the disease emerges. Keep the area clean and be sure to dispose of plant debris.

Fusarium wilt is a fungal disease that causes these symptoms in basil. High soil temperatures favor the disease emergence. Use only disease-free seed. Treat seeds with hot water to kill fungi before planting. Destroy affected plants at the first sign of fusarium. Rotate crops to nonsusceptible species.

Yellow leaves that wilt and die usually indicate Root rot. Several pathogens cause root rots of seedlings as well as mature plants. Poorly drained, overly wet soil promotes rot so choose well-drained sites and add organic matter to improve drainage. Remove and destroy infected plants. Solarize the soil before replanting.

Likely cause for these symptoms is a fungal disease - Rust. Provide good air circulation around plants by thining them. Avoid making leaves wet when watering. All infected leaves should be removed. Spray leaves with sulfur early in the season to prevent rust or to treat mild infections.

Distorted and curled leaves are caused by aphids. These tiny insects cluster under leaves and on growing tips where they feed on plant sap. Leaves, stems, and buds get distorted and later leaves and flowers drop from the plant. You can control them by washing them off the plant with water spray. Insecticidal soap should be used with severe infestations.

Large, ragged holes in the leaves are caused by slugs and snails. Slugs and snails feed on the plant leaves usually at night. To control slugs and snails use diatomaceous earth around your plants. You can also handpick them during the night or use shallow dishes filled with beer as a trap.

Poor growing conditions may have caused your flowers to have an unhealthy look. Four O'clock prefer full sun but will tolerate partial shade. They do well in rich, well-composted soil as they are big eaters. Keep soil moist. Add a general-purpose fertilizer once or twice a month to encourage vigorous growth.