|Japanese squash with bluish green skin, and yellow flesh, derived from Hubbard type, 4-5 lbs. Mature in 100 days. There is a great variety in shapes, colors and types of squash, making them fun to grow. Growing pumpkins can be a great project for kids. The vines need plenty of room to sprawl, although some can be supported on a trellis. Summer squash or pumpkins should be sown indoors in flats in short season areas, 3-4 weeks before the night soil temperatures have warmed up. Seedlings should be gradually hardened off. Plants prefer rich, compost enriched soil.