Partially covering a block of ‘Fuyu’ persimmon trees with polyethylene (plastic) cover increased fruit colour, weight, soluble solids concentration, and lowered soluble tannins in each of two seasons. These improvements to fruit quality may have been the result of higher temperatures in the block partially covered with plastic. Plastic covering also increased spring shoot growth and advanced flowering by 7 days. The beginning of harvest was advanced by 1 week, and the spread of harvest reduced by 10 days. The effects of plastic covering on fruit quality varied between seasons. The increases in fruit colour and soluble solids concentration were greater in 1989 than in 1990. The increase in fruit weight and the decrease in soluble tannin content were greater in 1990 than in 1989.