Gardenia Plant Pests

Gardenias are native to China.

Gardenias, or cape jasmine, are semi-tropical plants that perform best in warm, humid environments. They have large, glossy dark green leaves and fragrant, waxy white blossoms. A number of different insect pests attack gardenia plants.

Types

Nematodes, which are microscopic roundworms, are the most serious gardenia pest in Florida, according to the University of Florida IFAS. Other insects also attack gardenias. Spider mites are tiny 8-legged arachnids with oval-shaped bodies. Whiteflies look like small white moths; they are between 1/10 and 1/16 inch in length. Mealybugs are between 1/10 and 1/4 inch long; they are cottony-white and fluffy with sucking mouthparts.

Effects

Nematodes feed on the gardenia's roots; spider mites, whitefly nymphs and mealybugs suck plant juice from the leaves. Gardenias infected with nematodes lose vigor, wilt and lose their leaves. Spider mites, whitefly nymphs and mealybugs cause leaf discoloration or yellowing, plant dryness and leaf loss.

Prevention/Solution

Prevent nematodes by planting resistant varieties or plant grafted gardenias in locations where they are already adapted, according to the University of Florida IFAS. Treat spider mites, whitefly and mealybug infestations with environmentally friendly insecticidal soaps or horticultural oils.

References

• University of California Statewide Integrated Pest Management Program: Nematodes
• University of California Statewide Integrated Pest Management Program: Spider Mites
• University of Missouri Extension: Managing Whiteflies on Indoor and Outdoor Plants
• Toronto Botanical Garden: Toronto Master Gardener Factsheet
• University of Florida IFAS: Growing Gardenias in Florida
• University of California Statewide Integrated Pest Management Program: Gardenia