The leaves on my houseplant are covered with a sticky sap. There are also small “bumps” on the stems. What is the problem?
The houseplant may be infested with scale insects. These small, inconspicuous insects are covered with shell-like coverings. They attach themselves to stems or leaves and suck sap from the plants. As they feed, the scale insects excrete a sweet, sticky substance called honeydew. The honeydew accumulates on the plant’s lower foliage, furniture, carpeting or other objects beneath the infested plant.
The life cycle of scale insects consists of the egg, nymph and adult stages. Eggs are laid below the scale coverings of the adult females. When the eggs hatch, the nymphs crawl from underneath their mother’s scale and move a short distance to their own feeding site. The newly emerged nymphs are also called crawlers. At their new locations, the nymphs insert their slender stylets (mouthparts) into the plant and begin sucking sap. The covering or shell develops soon after feeding begins. The scale insects remain at these feeding sites for the rest of their lives.
A small scale infestation causes little harm to healthy houseplants. However, a heavy scale infestation may result in poor, stunted growth. In severe cases, death of infested plants is possible.
Scale insects are difficult to control. Systemic insecticides are generally ineffective. The shell-like covering protects the scale from contact insecticides. The only time scale insects are vulnerable to contact insecticides is during the crawler stage. Since scale insects on houseplants don’t reproduce at a specific time, scale-infested plants will need to be sprayed with insecticidal soap or other houseplant insecticide every 7 to 10 days until the infestation is eliminated. Small infestations can be controlled by individually scraping off the scales or by dabbing each scale with an alcohol-soaked cotton swab. It’s often best to discard houseplants that are heavily infested with scale as control is nearly impossible and the insects could spread to other houseplants.
Why does my fig tree lose some of its leaves during winter?
Environmental conditions indoors during the winter months are often rather poor. Low light levels, cold drafts, low relative humidities and other environmental factors are often stressful. These stressful conditions may cause figs and other houseplants to drop a few leaves in winter. Good, consistent care during the winter months should keep leaf drop to a minimum.
Most figs prefer brightly lit sites near windows. Sites near east and west windows are often best. Make sure the plants are kept away from cold drafts or heat sources. When watering, water figs and other houseplants thoroughly. Some water should flow through the potting soil and out the bottom of the pot. The excess water should be discarded. Allow the upper 1 inch of soil to dry before watering the fig tree again. Figs, like most houseplants, don’t need to be fertilized during the winter months.
What is the proper temperature for houseplants during the winter months?
Most houseplants grow well with daytime temperatures of 65 to 75 degrees F and night temperatures of 60 to 65 degrees F. Temperatures below 50 degrees F or rapid temperature fluctuations may damage some plants. Keep houseplants away from cold drafts, radiators and hot air vents. Also make sure houseplant foliage doesn't touch cold windows.
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