Complex sentence: Meanwhile, stimulated by antiquarian writings about British viticulture, Bute decided to reintroduce grape vines into the country in 1873 when his gardener Andrew Pettigrew was sent to France for training; a vineyard was established just beneath the castle in 1875.
Split into simpler sentences: Meanwhile, stimulated by antiquarian writings about British viticulture, Bute decided to reintroduce grape vines into the country in 1873. He sent his gardener Andrew Pettigrew to France for training, and planted a vineyard just beneath the castle in 1875.