Many common insect and disease problems are caused by overwatering, underwatering or excess fertilizing. Pest and symptom identification is essential for proper treatment of plant symptoms. For agricultural crops, the threshold when one should take action is based on economic considerations. Gall-forming insects may cause no real harm to a plant, but the results may offend some gardeners. Altering temperature, light and humidity are ways to indirectly control pests.
Beneficial organisms can help control unwanted ones.
Chemical control continues to have a role in IPM in the gardener's battle against pest problems. Recognize that all pesticides are toxic and require great care in their application. The home gardener should always consider the other management methods before using a pesticide. I've been told that shell ginger would be a good addition to the part of my garden that has tropical and subtropical plants. It also has been naturalized in Brazil and some regions of central and south Florida.