This publication provides practical, science-based guidance for managing weeds and volunteer crop plants in greenhouse and controlled-environment agriculture (CEA) production. It is intended for commercial greenhouse and hydroponic growers, crop consultants, Extension professionals, and others working in protected-crop systems. The publication explains why weeds can remain important in CEA even when direct crop competition is limited, including their potential roles in pest and disease cycles, seed production, sanitation problems, and harvest contamination. It provides growers with practical approaches for scouting, identifying recurring problem areas, tracking substrate lots and other possible sources of weed introduction, managing weeds around floors, cooling pads, drains, and other wet areas, preventing volunteer crops after turnover, and reducing establishment through sanitation and production-system design. Photographs from research and commercial greenhouse facilities, diagnostic tables, and a grower checklist are included to help readers recognize problems and determine appropriate corrective actions. Herbicide use is discussed conservatively, with growers directed to current labels and Virginia Cooperative Extension weed specialists for crop- and site-specific recommendations.

The intended audience for this publication includes greenhouse tomato growers, Extension agents, crop consultants, horticulture educators, greenhouse managers, and other agricultural professionals working with protected tomato production systems. The publication is especially useful for growers managing long-season or high-wire tomato crops who need practical guidance on identifying, preventing, and managing common greenhouse tomato diseases, including leaf mold, gray mold/Botrytis, and bacterial wilt. It is written to support both commercial growers and technical service providers who need clear, applied recommendations for scouting, sanitation, environmental management, and integrated disease management in greenhouse tomato production.