May 8, Looking for a great pick-me-up for your plants? Then consider putting your used coffee grounds to work in the garden. The following article will. Dec 12, Many people throw away their used coffee grounds but you can use Apply 2 coats on each side, drying with a hair dryer in between coats. The drying of spent coffee grounds in a cyclonic dryer was studied in the present work. Based on a experimental design, the effects of temperature of the air (Ta).