Chinese delphinium is considered an outstanding addition to a perennial garden. The plant grows from 2 to 3 feet tall and sends up spires of fragrant, long-lasting blossoms in shades of rich blue. While most delphiniums grow well in northern gardens, Chinese delphinium does well in southern temperatures. Protecting these flowers includes selecting the right location to plant them, as well as watching and treating for pests and fungus.
Select the site to plant Chinese delphinium. The taller varieties can be bent or broken from strong winds and they should be planted in a sheltered location. If the garden does not have sufficient shelter, use a plant support or use twine to secure the flowers to a stake.
Watch for aphids on new growth. Spray the delphiniums with water to remove them or treat by spraying them with pyrethrum or an insecticidal soap.
Protect from slugs; they can destroy the plants. Spread a 2-inch wide circle of diatomaceous earth or sharp grit around the plants and treat infestations with slug pellets.
Watch for powdery mildew during times of high humidity. Remove affected leaves and spray the plant with a fungicide.