This study determined the persistence of tomato pathogens (Solanum lycopersicum L.) on wooden trellises and their garters after three years of outdoor overwintering, followed by nine months of indoor storage at positive temperatures. The trellises were initially used in a plot with nine tomato varieties and hybrids during a pathogen epiphytotic in 2021 in the Kimry District, Tver Region. The trellises consisted of miscanthus stalks and wooden laths with garter materials (twine). Microorganisms were identified by rinsing the trellises and garters, followed by microscopic analysis using a Lomo Mikmed microscope equipped with a digital camera. The persistence of microorganisms was assessed based on the colonization rate (%) of trellises and garters by viable pathogens and associated microorganisms. Following the designated storage period, the following pathogens were detected: Cladosporium fulvum, Alternaria alternata, Phytophthora infestans, Phoma spp., and Epicoccum spp. Additionally, associated microorganisms such as Trimmatostroma spp., protococcoid algae (Protococcophyceae), and cyanobacteria were found. During the three-year storage period, approximately 2030 mm of precipitation occurred, and the minimum temperature reached –31.9 °C. After three years of outdoor overwintering, at least four major tomato disease agents persisted on the trellises. These experimental data on such long-term survival of tomato infection on trellises have been obtained for the first time and highlight the necessity of incorporating measures for the destruction or thorough disinfection of used trellises and garters after harvest into tomato cultivation guidelines.