What is the origin of the word plant when refering to large machinery?

Answer 1

plant and equipment
Personal property of a capital nature, consisting of equipment, furniture, vehicles, machine tools, test equipment, and accessory and auxiliary items, but excluding special tooling and special test equipment, used or capable of use in the manufacture of supplies or for any administrative or general plant purpose
The fixed assets that are used to produce the goods and services that a firm sells to its customers.
Plant
perhaps from *plantare "to drive in with the feet, push into the ground with the feet," from planta "sole of the foot," from nasalized form of PIE *plat- "flat" (see place (n.)). Ger. Pflanze, Ir. cland, Welsh plant," is O.E. plantian, from L. plantare, from planta. Most extended usages are from the verbal sense. Sense of a building "planted" or begun for an industrial process is first attested 1789