Greenhouse cultivation in Almería, Spain, has experienced continuous growth over the last five decades, and this area has established itself as one of Europe’s leading vegetable-producing regions. With 8201 hectares under cultivation, tomatoes are the most important crop, accounting for 63% of the total value of greenhouse tomato production in Spain. The aim of this study is to design and develop a tool that facilitates tomato trellising under greenhouse conditions and allows it to be carried out at the ground level. An operating principle is developed, and a static analysis of the tool is carried out. Time, costs, and risk of falling from height are compared with traditional methods (ladders, stilts, manual wheeled scaffolding, and motorized scaffolding). The tool incorporates a telescopic carbon fiber mast, a direct-current motor, and electromagnets. The results indicate that the tool is the second fastest method (4′38″) and has the second lowest cost (EUR 8026.93). It is concluded that it is a viable option for trellising, since it eliminates the risk of falling from height while maintaining competitive times and reasonable costs.