Green house production depends or reliable substrates and fertilizers. Peat is the dominating substrate in Sweden and internationally. There is a debate about reducing the peat use since the mining for peat may increase climate gas emissions and disturb sensitive ecosystems. Thus, alternative for peat replacement or for peat mixes is explored. Trials has revealed that the solid part of biogas digestate may be a useful candidate, especially since biogas production is increasing and plays an important role in the bio based society. This residue has physical properties resembling peat and is rich in plant nutrients. The project will study how pre-treatments and maturation affects the quality of the digestate for substrate use concerning nutrient availability and physical properties. Secondly, extensive growth trials with herbs and lettuce will be performed with different ratios of peat and digestate. Finally the used potting substrate will be evaluated as a compost in mushroom production.