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 yellow and the plant looks weakened?
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.
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.
Temperatures below 55 degrees can cause leaf discoloration. To prevent this issue, bring plants indoors to a warmer climate. Make sure the roots are kept warm in the winter by heavily mulching around your plant. Too much direct sunlight can cause sunburning on leaves. Not enough water or too low of humidity, and your plant’s leaves begin to dry at the edges.
https://www.epicgardening.com/crossandra/#Pests
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.
Sreten null
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/
