A blue-eyed daisy (Osteospermum spp.), also known as an African daisy, features a blue disk in the center surrounded by white, pink or yellow radiating petals. They grow as perennials in U.S. Department of Agriculture plant hardiness zones 10 and 11, but you can enjoy them as summer annuals in cooler climates. The daisies flower from spring through fall in mild summer regions. They thrive in dry soil, rarely suffer from pests or disease, and they require only minimal care.
Plant blue-eyed daisies in a well-drained bed that receives direct sunlight fo rmost of the day. Space shorter varieties 24 inches apart in all directions, and grow taller types up to 48 inches apart in all directions.
Water the daisies when the top 1 inch of soil begins to dry but before the soil dries completely and causes the plants to wilt. Provide approximately 1 inch of water weekly with irrigation if not provided by rainfall. Avoid wetting the foliage when watering. Wet blue-eyed daisy foliage is prone to fungal diseases that can destroy the plants.
Check the daisies weekly and during damp weather for fungal diseases, which may appear as a powdery residue, black spots, or gray growth. Spray affected plants with a premixed biological fungicide or fungicidal oil, coating all affected parts of the plant. Reapply the fungicide at 10 day intervals. Wash your hands and clean all tools with a 1 part bleach to 9 parts water solution to prevent the spread of fungal spores when tending the plants.
Apply an all-purpose soluble fertilizer every two weeks. Combine 1 tablespoon of a 24-8-16 blend with 1 gallon of water, and water every 10 square feet of the daisy bed with the solution.
Cut back the dead flowers as they begin to wilt, using clean shears disinfected in a solution of 1 part bleach and 9 parts water. Frequent deadheading as the flowers fade forces new blooms so the daisies continue to flower through summer and into fall.
Monitor blue-eyed daisies for aphids, which are small soft-bodied insects that tend to feed on the underside of the leaves. Spray aphids with a ready-to-use insecticidal soap spray, reapplied at three-day intervals until the insects are gone.
Things You Will Need
- Fungicidal oil spray
- All-purpose soluble fertilizer
- Watering can
- Premixed insecticidal soap
- Blue-eyed daisies also grow well in containers. Use pots with bottom drainage holes and plant in a well-draining soilless potting mixture.