Growing melon under temperate climate conditions is quite risky due to the high climatic requirements of this species. Vegetable growers use plastic film mulches to heat soil, to reduce weed infestation, and to maintain optimal soil moisture content. The aim of our study was to determine the suitability of white and black plastic film for soil mulching in melon cultivation under temperate climate conditions. Plants of three Polish heterotic cultivars of melon (C. melo L. var. saccharinus Naud.): Emir F1, Junior F1, and Seledyn F1, as well as of the breeding line 61/2014 F1 were the subject of this study. Two soil mulching methods were applied: black polyethylene (PE) plastic film and white PE plastic film, using for this purpose double-sided whiteon-black PE plastic film. The use of black plastic contributed to a significant increase in marketable yield of melon fruits. The content of L-ascorbic acid and carotenoids in fruits of melon grown on white mulch proved to be higher than in those grown on black mulch. The Polish cultivars studied can be considered as tolerant to temperate climate conditions.