Immediate removal is important because certain fungal pathogens can develop and produce spores on the plant debris. Weeds along walkways and under benches can harbor diseases that can be transmitted to greenhouse crops. Non-sterile soil from outdoors should not be allowed into the greenhouse. Since many soilborne pathogens can be a serious problem if introduced into the greenhouse, the best control method is to exclude these pathogens from the greenhouse. This can be accomplished by using a soilless medium which is free of plant pathogens.
Surface sterilize all work surfaces and tools regularly to prevent accidental disease spread.
Diseases are often transferred in the greenhouse through used pots, dirty tools, messy work surfaces, unswept floors, etc. Precautions should be taken to prevent this. Dr. Anderson is Extension Floriculture Specialist, Department of Horticulture and Landscape Architecture. The use of some products may not be legal in your state or country. Please check with your local county agent or regulatory official before using any pesticide mentioned in this publication.