Peat has over the last decades become the dominant growth medium for commercial and hobby-based ornamental and vegetable production and for the raising of small plants. Due to adverse environmental and ecological effects caused by peat extraction and use, it is desirable to reduce or phase out the use of peat.
Peat-free products made from composted fallen leaves and horse manure have yielded good results in raising cauliflower and iceberg lettuce in previous tests conducted by NORSØK. The composts used were about 3 years. It is unclear how long the materials should be composted before they function satisfactorily as transplant media. In this project we will try out composts of different ages and degree of decomposition as transplant media for cauliflower and lettuce.