Pests on houseplants and seasonal outdoor plantings are usually unexpected and always an inconvenience. Holes in leaves, browning stems and a general decline in plant health may result from a pest infestation. To keep your valuable plants in top condition, learn to find and correctly deal with plant pests naturally, whether on your indoor peace lily or your outdoor hydrangea. Chemical control is not recommended in most situations.

Common Indoor and Outdoor Plant Pests

Fungus Gnats

These are small flying insects that look like the mosquito. Most of them are about 1⁄16 to 1⁄8 inch long. They aren’t harmful to people or pets, but infest soil and may damage plant roots if left untreated. Fungus gnats are relatively weak fliers that are sometimes found around a forgotten bag of potatoes in the pantry when rotting starts.  Such rot indoors and that of outdoor plant materials attract these gnats. They lay eggs in the soil, resulting in many young pests. Gnats are sometimes confused with fruit flies. Fungus gnats on houseplants inside are usually the result of overwatering. Water thoroughly, then allow the soil to dry out, at least the top two inches. This will clear up problems with pesky fungus gnats. Use BTI, Bacillus thuringiensis israelensis, an organic bacteria, for further control. It is also known as mosquito bites.

Fruit Flies

These flying insects are light brown with some types having red eyes. Most are about a ⅛ inch, requiring a magnifier to see details.  You’ve seen them buzzing around overly ripe fruit, or peels and may recall they’re easily confused with fungus gnats. Fruit flies are certainly a nuisance, but more importantly, they may contaminate food with which they come into contact. It is prudent to get rid of fruit flies in the kitchen as quickly as possible. Keep food covered at picnics and other outdoor gatherings. Avoid fruit flies by quickly disposing of peelings outside and refrigerating produce immediately. A small jar of vinegar nearby attracts this pest away from your plants, encouraging them to plunge to their demise. BTI is right for fruit fly control when there are too many to control with vinegar.

Spider Mites

Tiny red dots moving around on plant leaves, both indoors or outside are likely a case of spider mites. Cottony, white webbing on the underside of leaves is a sign. Tan, white or yellow spots on foliage, called stippling, shows the damage they’re doing and along with the webbing indicates that a pest infestation has started. These are of the spider family, hence the name. Control spider mites before they spread further. You may find them on trees and shrubs, such as azalea and rose. Annual bedding plants, like Lantana and Marigold, are often targets. The mites attack vegetables growing in the garden and fruit trees, vines and bushes, particularly during hot, dry weather. Well watered plants are less likely to experience this pest. Untreated infestations result in stunting and even death of the plant. Spray plants with a full force garden hose to remove pests and the webbing. Look for them a few days later, using a hand lens. Spray insecticidal soap or Neem oil if any mites remain. Spray the underside of leaves and stems completely. Repeat until they are gone.


This is another insect type that appears in hot, dry weather. The piercing, sucking mouthparts of the pest sink into stems and leaves where the scale develops a covering. It flattens itself to blend in and continue feeding. There are soft scale and armored scale. These are small, 1/8 to ½ inch, and attack both fruit and shade trees and shrubs. Scale weakens a tree and can cause death if not treated. This is preceded by yellowing leaves, stunted growth and a loss of vigor. These may attack houseplants that are vacationing outside. The scale does not fly, but there is a stage when the insect crawls. Mealybugs are of the same order as scale, with similar control methods. Beneficial insects, like lady beetle and predatory wasps, help control infestations and keep the scale population low. If this fails, perhaps you will turn to a chemical insecticide. Use a systemic, injectable insecticide or a foliar spray. In some states, only licensed pest care professionals can buy this product.  

If insect infestations are severe in your corporate landscape, you may find hiring a professional is the most effective way to get rid of them. If you are short on time or horticultural ability contact the professionals at Cityscapes. We choose from your favorite plant selection and install per your wishes, along with all maintenance, including pest control.