Nothing frustrates the avid gardener more than the presence of pathogens and harmful insects in the summer garden—disfiguring leaves, ruining fruit production, stunting growth and disrupting overall aesthetics. To further complicate matters, different pathogens can produce similar symptoms while some insect infestations can even mimic signs of disease. Take heart, however, because many diseases and insect problems can be treated, controlled or prevented with some initial planning and routine monitoring along with a basic knowledge of plant diagnostics.