Long-term fluorescence live-cell imaging experiments have long been limited by the effects of excitation-induced phototoxicity. The advent of light-sheet microscopy now allows users to overcome this limitation by restricting excitation to a narrow illumination plane. In addition, light-sheet imaging allows for high-speed image acquisition with uniform illumination of samples composed of multiple cell layers. The majority of studies conducted thus far have used custom-built platforms with specialized hardware and software, along with specific sample handling approaches. The first versatile commercially available light-sheet microscope, Lightsheet Z.1, offers a number of innovative solutions, but it requires specific strategies for sample handling during long-term imaging experiments. There are currently no standard procedures describing the preparation of plant specimens for imaging with the Lightsheet Z.1. Here we describe a detailed protocol to prepare plant specimens for light-sheet microscopy, in which Arabidopsis seeds or seedlings are placed in solid medium within glass capillaries or fluorinated ethylene propylene tubes. Preparation of plant material for imaging may be completed within one working day.