This disease is caused by one of several fungi (including Colletotrichum and Gloeosporium species). Spores of these fungi infect the leaves, causing the spots. The disease is most virulent under wet and humid conditions. For this reason, the disease is not common in houseplants. However, it is common on ficus summering outdoors in wet climates, and on those raised in greenhouses. Rubber plants (F. elastica) and fiddleleaf fig (F. lyrata) are particularly susceptible. Wounded or damaged spots are particularly susceptible to infection.
Pick off and destroy spotted leaves and prune off badly infected branches. Spray plants with a fungicide labeled for this disease. Avoid injury to the plant. Keep the leaves dry if possible. Do not mist infected plants. Do not let the plants dry out or expose them to extremes of heat or cold.
Gynaikothrips ficorum Cuban laurel (Ficus retusa), especially the variety ''Nitida'', may be severely infested with these thrips in Hawaii, California, Florida, and Texas. Other species of ficus are attacked only if the insects do not have enough Cuban laurel leaves to feed on when they are abundant. Thrips feed on plant sap by shredding and rasping the plant tissue, resulting in distortion and spotting. Damage is unsightly, but the feeding does not cause permanent injury to the plant. On hot days the adults fly around the plant and infest new leaves. Breeding is almost continuous, but populations are highest between October and December.
Apply an insecticide labeled for Cuban laurel thrips, following label directions.
Edema, also called oedema, is a disease found on many plants. It is caused not by infection but as a result of environmental factors. Excessive watering during periods of high humidity is believed to cause edema, but the disease also develops sometimes in plants that are kept dry and in low humidity. In ficus, a milky juice may leak out of the corky spots. When this juice dries, it leaves a brown spot on the raised area.
Give ficus adequate light and moisture. Avoid keeping the soil too wet, especially during periods of cloudy, damp weather. Avoid letting plants dry out.
Weeping figs may drop their leaves in response to any of the following conditions. 1. Overwatering: When plants are watered too frequently or soil drainage is poor, the roots are susceptible to root-rotting fungi. Weak and decaying roots cannot provide enough water and nutrients for proper plant growth. 2. Underwatering: Weeping figs need constantly moist soil. If plants are not watered frequently enough or if the soil is not thoroughly soaked at each irrigation, the plants respond by dropping their leaves. 3. Insufficient light: Weeping figs need bright indirect light or direct sunlight for best growth. They may drop their leaves even in locations that are bright enough for most other foliage plants. 4. Transplant shock: Transplanting always results in some disturbance to the rootball. Weeping figs are likely to drop some leaves even when the disturbance is minimal. 5. Changes in environment: Drafts and extreme fluctuations in temperature, light levels, and watering patterns are likely to cause leaf drop. When a greenhouse-grown plant is brought into a drier, darker, cooler home environment, it often responds to the change by dropping many of its leaves. The same holds true for plants originally grown in outdoor nurseries in semitropical climates, such as South Florida.
Allow the plant to dry out slightly between waterings. Empty the saucer after the pot has drained. Be sure to use light, well-draining potting mix. Move plants to a bright location. Move them gradually, slowly increasing their exposure to light. Don''t disturb the rootball when transplanting. Some leaf drop after transplanting is normal. Avoid drafty areas and any sudden environmental changes.
Several species of this common insect feed on ficus. Mealybugs damage plants by sucking sap, causing leaf distortion and death. The adult female mealybug may produce live young or may lay eggs in a white, fluffy mass of wax. The immature mealybugs, called nymphs, crawl all over the plant and onto nearby plants. Soon after they begin to feed, they produce white, waxy filaments that cover their bodies, giving them a cottony appearance. As they mature, they become less mobile. Mealybugs cannot digest all the sugar in the sap, and they excrete the excess in a fluid called honeydew, which coats the leaves and may drop onto surfaces below the plant.
Separate infested plants from healthy ones. Apply an insecticide labeled for mealybugs. If only a few bugs are present, wipe them off with a damp cloth or with cotton swabs dipped in rubbing alcohol. Inspect new plants thoroughly before putting them in the house.
Several different types of scale insects attack ficus. Some types can infest many different plants. Scales hatch from eggs. The young, called crawlers, are small (about 1/10 inch) and soft bodied and move about on the plant and onto other plants. After moving about for a short time, they insert their mouthparts into the plant, feeding on the sap. The legs disappear, and the scales remain in the same place for the rest of their lives. Some develop a soft covering, others a hard covering. Some species of scales are unable to digest fully all the sugar in the plant sap, and they excrete the excess in a fluid called honeydew, which may cover the leaves or drop onto surfaces below.
Isolate infested plants as soon as scales are discovered. Remove as many scales as possible with a cloth or toothbrush dipped in soapy water. Apply an insecticidal soap or horticultural oil, following label directions. Avoid bringing scale crawlers into the house.