How to Manage Pests
UC Pest Management Guidelines
Control weeds outside the greenhouse to help prevent movement of their seeds into the greenhouse. Weed control in the area around the greenhouse will also reduce the chances that insect and disease pests that may live and reproduce on weeds will move into the greenhouse. If insects such as aphids, thrips, leafhoppers, whiteflies, or lygus bugs are abundant on the weeds outside the greenhouse, it may be desirable to control them before the weeds are removed, or these insects may move into the greenhouse when the weed host dies.
Weeds outside the greenhouse can be controlled by mowing or cultivation where feasible and with herbicides. Care must be used when applying an herbicide so that it does not get in the greenhouse by drift or runoff. Preemergent herbicides can be used if the soil slopes away from the greenhouse so no water or soil that may contain an herbicide gets into the greenhouse. Vents in the greenhouse and fans should be closed or shut off while herbicide applications are being made so that the herbicide will not be drawn into the greenhouse. Also volatile herbicides (such as oxyfluorfen) should not be used around the outside of a greenhouse.
UC IPM Pest Management Guidelines: Floriculture and Ornamental Nurseries