The current study describes the effect of coloured plastic mulch, clear and black polyethylene (PE), on growth and productivity of different summer squash varieties grown on February “off-season". A field experiment was carried out during 2012 and 2013 seasons at the Experimental Farm of Faculty of Agriculture, Assiut University, Assiut, Egypt. The performance of different parameters studied for plant received different mulch treatments was superior to the control (bare soil) treatment. The genotypic differences among squash varieties investigated were found significant for all the studied parameters. Clear PE mulch was significantly more effective than the black PE mulch in this respect. Plants of cvs sown on clear PE flowered earlier than those sown on black PE or bare soil.Total fruit yield (ton/fed) was significantly increased by using clear PE (total fruit yield was 12.61 and 12.94 ton/fed in the 1 ^st and 2 ^nd seasons, respectively; corresponding values for the bare soil were 7.61 and 7.74 ton/fed). Plants of ‘Eskandrany' produced using clear PE were significantly the earliest to flower and gave the highest early and total fruit yield. It is concluded that mulching, especially clear PE, can be usefully utilized to enhance the summer squash production when grown off-season.