Three different heating devices (Hot plate (HP), Autoclave (AC) & Microwave (MW)) were tested for their efficiency to pretreat garden biomass (GB), a lignocellulosic substrate. Effectiveness of different modes of heat on pretreatment was assessed taking into consideration the yield of reducing sugar (RS), recovery of cellulose after pretreatment, conversion of hemicellulose into reducing sugar, changes in the ultra structure of GB tissues, changes in the crystallinity of GB etc. The results indicated that all three heating devices are useful for pretreatment, however, the efficacy of MW on GB was found be better than AC and HP. A maximum of 53.95% of cellulose recovery was obtained in case of MW heating along with 46.97% of reducing sugar yield. This when compared to AC and HP is significantly higher (more than 10% increase) and time saving (only 15 min reaction time) as well. (C) 2010 Elsevier Ltd. All rights reserved.