A surprise cold snap can make a healthy tray of seedlings look rough overnight, even when everything’s technically “indoors.” Leaves curl, stems go limp, and the soil suddenly stays wet like it forgot how to dry. The frustrating part is that many setups look protective but don’t actually hold steady warmth where seedlings need it most. That’s why indoor greenhouses can feel like a safe shortcut, then disappoint the second temperatures swing. Here’s what experts flag as the real weak points, plus simple fixes that keep seedlings alive without turning your home into a science lab.
