The trellis supports of plants significantly affect their mechanical properties. Because trellises are usually used in grape plantations, their mechanical properties were measured in these systems. Vibrational grape harvesting was simulated using a finite element method. The major component of the vibration system is primarily represented by an elastic wire, and the green plants act as a mass with damping properties. The harvester ‘excitation’ was assumed to be sinusoidal with defined parameters. The real acceleration was measured during operation. The measured and calculated results correlated well. The process of detaching the crops can be determined using the calculated tearing force. This method helps to determine the dimensions of the trellis system and characterise the harvester’s operation.