Knowing when to harvest tromboncino squash means choosing between tender, pale green fruit for summer meals and hard, tan fruit for winter storage.
Essential Concepts
Summer: usually 8–18 inches, tender skin. Winter: hard, tan rind; size alone does not establish maturity.
Related reading: Growing pumpkins and winter squash, https://extension.umn.edu/vegetables/pumpkins-and-winter-squash


