What Is Wrong With My Spiked Speedwell?

Are the leaves covered with white powder?

Do the leaves have pale areas on upper surfaces and "downy" patches underneath?

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

Are the leaves stippled with yellow and the foliage is webbed?

Are there any streaks on leaves and blister-like lesions near the base of the plant?

Did the leaves become distorted due to excess moisture in the soil?

White, powdery patches on the leaves are caused by a fungal disease Powdery mildew. Powdery mildew usually appears in damp places. Encourage good air circulation around the affected plants by thining them and any surrounding plants. Water plants from below to keep foliage dry. Any affected leaves should be cut off and removed. The appropriate fungicidal spray will protect your plant from further infections.

Pale areas on upper surfaces of the leaves and "downy" patches underneath are caused by Downy mildew. This fungus spreads quickly during cool, wet nights and warm, humid days. Leaves will wilt and die. Remove and destroy all affected plant parts and encourage good air circulation around plants by thining them. Water plants early in the morning to make sure they dry before nightfall.

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.

Leaves stippled with yellow and webbed foliage is caused by spider mites. These tiny, spider-like pests feed by sucking sap from the underside of the plant's leaves causing yellow flecking on the upper leaf surfaces. You can control spider mites by spraying plants thoroughly with water 2-3 times a day for several days. For severe infestations, spray plants with insecticidal soap, or pyrethrin as a last resort.

Smut fungus attacks mostly young seedlings as the new leaves emerge. It causes blister-like lesions near the base of the plant and streaks on leaves. The streaks mature into black powdery spores. The fungus stunts the growth of the plants. More mature plants are not as susceptible. If the infection is mild, cut off and destroy all infected leaves. In more severe infections all you can do is destroy plants to stop smut from spreading.

If a plant has absorbed more water than it needs, it can cause the plant’s cells to expand and stress. Often, these cells are filled to the point of rupturing. Burst cell damage is called edema. You can check for signs of edema by noticing any blisters or lesions on the plant. Eventually, these lesions will turn to dark or even white scar tissue. Another sign of edema is indentations on the top of leaves.

If your plant has yellow leaves that wilt and die it may be suffering from 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.