Abstract: Methods for obtaining a biocrude intermediate by hydrothermal liquefaction of plant wastes are provided. Using a waste feed having a high cellulose content, the method involves grinding the waste feed to obtain a pulverized waste feed, and subjecting the pulverized waste feed to hydrothermal liquefaction at a temperature at or greater than at about 250° C. At this temperature or greater a catalyst is not necessary to obtain the biocrude. A lower temperature can be used, such as greater than about 150° C. in presence of a catalyst. The step of grinding the plant material, for example ball grinding, reduces particle size and crystallinity, and combined with the high temperature treatment improves the yield of biocrude. Biocrude can be upgraded to biofuel by high temperature hydrodeoxygenating in the presence of hydrogen. Plant wastes that would otherwise contribute green house gases are instead converted to fuels.