Sweetcorn Glass Gem Glass Gem Plant profile - Sweetcorn Glass Gem back to category view all profiles Variety Glass Gem Type Flint corn, popping corn Growing Conditions Full sun Plant Height 180cm Plant Spread 40cm Plant on/out After last frosts Sow March - May Harvest When silks are brown and the plants have started to die back Position Plant in blocks to aid wind pollination Supplier Premier Seeds Direct Tasting notes and description The cobs can be dried for decorations, used as popping corn or ground for flour. Uses Use for Autumn decorations and for popping corn.