Using a greenhouse or hoophouse to grow food in a northern climate helps extend the growing season by creating a controlled environment that shields plants from harsh weather and frost. Greenhouses, typically made of glass or plastic, offer year-round growing potential by trapping heat and sunlight, while hoophouses, with their simple, arch-shaped frames covered in plastic, provide a more affordable option for season extension. Both structures enable gardeners to grow a variety of vegetables, herbs, and even some fruits in cooler climates, allowing for earlier planting, longer harvests, and protection from unpredictable northern weather.