Protect garden seedlings from spring frost by creating a mini greenhouse from an empty soda bottle. Simply use a utility knife to slice off the bottom of the bottle, then place it over the seedling. The bottle will capture the sun’s energy and warmth during the day to help the plants grow quickly. But if it gets too hot, you can simply twist off the cap and let some of that heat escape. At night, put the cap back on to protect the seedling from the cold.