Do you save seeds? If so, was the previous plant a hybrid (indicated as an "F1" usually). You can save F1 seeds and might get good plants in following years, but it is more likely the later generations will not grow true to form (as the original plant did).
I tried saving seeds from a "Toadskin" aka "Christmas" melon not realizing the original was an F1 hybrid (apparently all Toadskin melons are sold as F1 hybrids). The resulting plants grew okay but either didn't set fruit or the fruit that was produced was inferior.
