From our perspective as African Daisies (Osteospermum spp.), our vibrant, sun-seeking blooms are a point of pride. However, our lush foliage and abundant flowers can attract unwanted attention from various pests and pathogens. A healthy life for us depends on your ability to recognize the distress signals we send and provide the appropriate care.
We often find ourselves under attack by small, sap-sucking insects that weaken our vitality. Aphids are a frequent nuisance; you will see them as tiny green or black insects clustering on our tender new growth and flower buds. They pierce our tissues and drain our sap, causing our leaves to curl, pucker, and become sticky with a substance called honeydew. A strong spray of water can often dislodge them, or you can apply insecticidal soap. Another common pest is the Spider Mite. These minuscule pests thrive in hot, dry conditions, spinning fine, silken webs on the undersides of our leaves. They cause a stippled, yellow discoloration, and a severe infestation can leave our foliage bronzed and withered. Increasing humidity and using miticides or horticultural oils can help control them. Thrips are slender insects that rasp our petals and leaves, leaving behind silvery streaks and deformed, stunted flowers.
Our leaves are susceptible to several fungal diseases, often exacerbated by poor growing conditions. Powdery Mildew is one of the most recognizable. It appears as a white or gray, powdery coating on our leaf surfaces, stems, and sometimes flowers. It thrives in humid conditions with poor air circulation. While it rarely kills us outright, it stresses us, reduces our flowering, and makes us unsightly. Improving air flow around our stems and applying a fungicide labeled for mildew can manage this issue. Another concern is Leaf Spot, which manifests as brown or black spots on our foliage, often with a yellow halo. These spots are caused by various fungal or bacterial pathogens, typically spread by water splashing onto our leaves from the soil. It is crucial to water us at the base, avoid wetting our foliage, and remove any severely infected leaves to prevent the disease from spreading.
The most serious threats to our survival often begin below the soil surface. Root Rot and Crown Rot are devastating conditions usually caused by overwatering or poorly draining soil. Fungi like Pythium or Phytophthora attack our root system, causing it to become dark, mushy, and ineffective. Above ground, you will see us wilt, despite the soil being wet. Our growth will be stunted, and our leaves may turn yellow and drop. Unfortunately, by the time these symptoms are visible, the damage is often advanced. Prevention is the only reliable strategy: ensure we are planted in very well-draining soil and avoid overwatering, allowing the top layer of soil to dry out between waterings.
The best way to help us fend off these problems is through proactive, preventative care. Please plant us in a location with full sun, which strengthens our tissues and reduces humidity around our leaves. Ensure the soil is loose and very well-draining. When watering, please direct the water to our base, avoiding our leaves entirely. Provide adequate spacing between us and other plants to ensure good air circulation, which helps our foliage dry quickly and discourages fungal growth. Regularly inspecting our leaves, both top and bottom, will allow you to catch any issues early when they are most manageable.
