When Do Cora Cascade Periwinkles Bloom?

Location

• "Cora Cascade" may only be grown as a perennial in the warm, frost-free climate of U.S. Department of Agriculture plant hardiness zone 11. Elsewhere, the plant may be cultivated as an annual during the growing season. Plant "Cora Cascade" in a bright, sunny location. Though the plant may tolerate a little shade, flowering will be reduced and the plant's habit sparser. "Cora Cascade" works well in a border or bed, and can be charming in a container with its flowers cascading over the side.

Culture

• Madagascar periwinkles do best in a well draining, sandy loam that is slightly alkaline to acidic. Because periwinkles are prone to root rot, you may want to plant the flower in a raised bed to promote drainage. If planting multiple periwinkles, provide 12 to 18 inches of space to avoid overcrowding. Spent flowers will drop off on their own throughout the growing season. You can pinch back newly planted periwinkles to encourage a bushier habit with more flowers.

Problems

• Though the "Cora Cascade" series is considered resistant to blight, Madagascar periwinkles generally are highly susceptible to diseases such as rot root. The University of Florida Extension recommends watering Madagascar periwinkles no more than two or three times after planting, noting that just three months of colorful, disease-free flowers is considered a very good return. Therefore, the flowering season may not last from late spring until fall, depending on the amount of rainfall in your region.

Considerations

• All parts of Madagascar periwinkle, including the flowers, contain vinca alkaloids that are toxic to humans if ingested. Warn children not to put the colorful flowers in their mouths. They also pose a risk to dogs, cats and horses according to the ASPCA, potentially causing symptoms such as vomiting, diarrhea, depression, tremors, seizures, coma and death. If your pet ingests part of your "Coral Cascade" plant, contact your veterinarian or call the ASPCA Animal Poison Control Center at 888-426-4435.