► Rapid composting process of wet olive husk through the use of a selected microbial starter. ► Improved germination index and detoxification of humid olive husks. ► This compost from wet olive husks can substitute for turf as cultivation substrate. ► This compost influences positively the nutraceutical traits of tomato. The production of a compost from olive wet husks is described. The process is enhanced through the use of starters prepared with virgin husks enriched with selected microbial cultures. This approach, with respect to composting without the use of starters, allows to achieve faster start of the process (10 vs. 45days), deeper humification (humification rate 19.2 vs. 12.2), shorter maturation time (2 vs. 4–5months) and better detoxification of the starting material. Furthermore, the compost produced can effectively substitute for turf as a cultivation substrate in horticulture at greenhouse level, with beneficial effects on nutraceutical traits of tomato fruits.