Native plant production greenhouse.

Chemicals and Natives

Many people have concerns about the use of chemicals on plants. The range of herbicides, insecticides, fungicides, fertilizers, and other chemicals used in agriculture, on lawns, in the horticulture trade, and in home gardens is very broad. 

In many greenhouse situations, insect pests can create serious challenges for all plant growers, and growers must use chemical or biological controls to remain financially viable. Many if not all states have laws prohibiting the transportation of live plants with insect pests on them. Therefore, if plant growers wish to sell plants across state lines, they must ensure that their plants are pest-free before, during, and after transit.

Plant growers may use a wide variety of methods to control greenhouse pests. Some of these methods may pose no threat to insects you want to attract in your landscaping, or they could have long-lasting effects. Systemic insecticides that are contained throughout a plant, for example, may be long-lasting or short-lived. If long-lasting, they may harm the wildlife you are trying to support with native plants. For example, if certain systemic insecticides have been applied to milkweed plants, when monarch caterpillars eat the milkweeds, they could be poisoned and die. Growers are required under federal law to maintain a log documenting  chemicals used for treating pests on their property. When buying plants, ask the grower or retailer about how the plants were grown.

There are many other chemicals—some commonly used around homes–that can impact native plants. For example, chemicals in dog tick or flea collars can harm natives—even if a dog with a collar walks next to native plants, insects on them can be damaged or die. 

Consult this Grow Native! fact sheet on native plants and chemicals for more information.