I am also going  guess a cantaloupe but it could be another type of melon. A cantaloupe can be harvested when the stem is at the "slip" stage. This is when slight pressure causes the stem where it joins with the melon to slip right off. Casaba and Honeydew melons are ripe when the skin turns yellow. You should know in a few months if our guess is correct. Let us know how your harvest does and Keep Growing, Marianne Binetti