Are there yellow, V-shaped spots on leaf margins?
Does your plumeria have mottled or streaked leaves?
Are the growing tips blackened?
Are the leaves stippled with yellow and the foliage is webbed?
Are the leaves curled and distorted, sticky to the touch?
Do the leaves and stems have white, cottony clusters on them?
Are the leaves covered with small bumps?
Are there any small holes oozing a black substance in the stems?
Are the leaves yellow and the plant looks weakened?
Do the leaves have large, ragged holes in them?
Are the leaves pale on their upper side and are there any dusty blisters on the undersides?
Yellow, V-shaped spots most likely indicate a bacterial disease - Black rot. Infected leaves will die and drop off. Destroy infected plants. Spray copper if the weather is wet and if you had problems with black rot in the past.
Mottled or streaked leaves are caused by Mosaic virus. There is no cure for infected plants. Remove and destroy all flowers that have the symptoms of the mosaic virus. Mosaic virus is spread by aphids, so the best way of preventing the disease is to control these insects.
Black tip is a fungal disease that is promoted by cool, wet, and shady areas.
Leaves stippled with yellow and webbed foliage is caused by spider mites. These tiny, spider-like pests feed by sucking sap from the underside of the plants leaves causing yellow flecking on the upper leaf surfaces. You can control spider mites by spraying plants thoroughly with water 2-3 times a day for several days. For severe infestations, spray plants with insecticidal soap, or pyrethrin as a last resort.
Distorted and sticky leaves and stems are caused by aphids. These tiny insects cluster under leaves and on growing tips where they feed on plant sap. Leaves, stems, and buds get distorted and latter leaves and flowers drop from the plant. You can control them by washing them off the plant with water spray. Insecticidal soap should be used only with severe infestations.
White, cottony clusters on leaves and stems are caused by mealybugs. These tiny insects are covered with a fluffy white coating. They feed by sucking plants sap. They produce sticky substance honeydew which makes leaves sticky. You can control them by washing them off the plant with water spray. Insecticidal soap should be used with severe infestations.
Leaves covered by small bumps are caused by scales. These tiny, shelled insects often feed on the undersides of the leaves, causing an unhealthy appearance with yellowish blotches on the upper leaf surfaces. Scrape off minor infestations with your fingernail. Prune out badly infested growth, or use a soft brush and soapy water to gently scrub the scales off the stems. Control scales by spraying insecticidal oil during the growing season.
This is a sign of longhorn borer infestation. Infected limbs should be cut off the tree and burned immediately. Although the holes may not be actively oozing in the dormant season, cut away any bent and shriveled limbs with these holes at the base during winter pruning.
Yellow leaves and stunted look are caused by whiteflies. These tiny, mothlike flies and their larvae feed by sucking plant juices. Whiteflies secrete honeydew, a sugary substance that makes leaves sticky to the touch. Control whiteflies by eliminating garden weeds and by introducing green lacewings in the garden. Spray infested plants with insecticidal soap every 3 days for 2 weeks.
Large, ragged holes in the leaves are caused by slugs and snails. Slugs and snails feed on the plant leaves usually at night. To control slugs and snails use diatomaceous earth around your plants. You can also handpick them during the night or use shallow dishes filled with beer as a trap.
Likely cause for these symptoms is a fungal disease - Rust. Provide good air circulation around plants by thining them. Avoid making leaves wet when watering. All infected leaves should be removed. Spray leaves with sulfur early in the season to prevent rust or to treat mild infections.
If your plumeria has stopped growing and it's losing leaves it is normal with deciduous varieties when days are getting shorter and the dormancy period gets triggered. You should prepare the plant for winter storage or provide it artificial light.
Ellis, B. W., Bradley, F. M., & Atthowe, H. (1996). The Organic gardener's handbook of natural insect and disease control: a complete problem-solving guide to keeping your garden & yard healthy without chemicals. Emmaus, Pa.: Rodale Press.
Hi! I’m Sreten Filipović. I graduated from the Faculty of Agriculture at the University of Belgrade, with a master's degree in Environmental Protection in Agricultural Systems. I’ve worked as a researcher at Finland's Natural Resources Institute (LUKE) on a project aimed at adapting south-western Finland to drought episodes. I founded a consulting agency in the field of environment and agriculture to help farmers who want to implement the principles of sustainability on their farms. I’m also a founding member of the nonprofit organization Ecogenesis from Belgrade whose main goal is non-formal education on the environment and ecology. In my spare time, I like to write blog posts about sustainability, the environment, animal farming, horticulture, and plant protection. I’ve also published several science-fiction short stories. You can find me on LinkedIn at https://www.linkedin.com/in/sreten-filipovi%C4%87-515aa5158/