As the temperature drops and frost nips at the garden, many growers think their harvesting season is over. But with a few simple, budget-friendly structures—cold frames, hoop houses, and low tunnels—you can extend your growing season well into winter, and even achieve year-round harvests. These DIY setups require minimal tools, affordable materials, and no advanced gardening skills, making them perfect for home gardeners looking to maximize their harvests without breaking the bank.
1. Cold Frames: Compact Protection for Small-Space Gardens
Cold frames are essentially mini greenhouses that leverage solar energy to trap heat, creating a sheltered microclimate for cold-hardy crops. They’re ideal for raised beds, containers, or small garden plots, and you can build one in an afternoon with reclaimed or cheap materials.
How to Build a Low-Cost Cold Frame
The simplest design uses a wooden frame (or even cinder blocks for the base) and a clear cover to let in sunlight. Here’s a step-by-step guide:
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Frame Materials: Use reclaimed lumber (pallets work great!), 2x4s, or cinder blocks. The size can vary—aim for 3-4 feet wide (easy to reach across) and 6-8 feet long. The front height should be 12-18 inches, and the back 18-24 inches (sloped to catch maximum sunlight).
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Cover: Repurpose an old window pane, clear plastic sheeting (6mm thick is durable), or a polycarbonate panel (more long-lasting but slightly pricier). Secure the cover with hinges (for easy opening) or bungee cords (for quick adjustments).
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Placement: Position the cold frame facing south (in the Northern Hemisphere) to soak up sunlight. Avoid windy spots—adding a layer of mulch around the base will insulate the soil and prevent heat loss.
Pro tip: Add a thermometer inside to monitor temperatures—aim for 40-60°F (4-15°C) for most winter greens. On sunny days, prop open the cover slightly to ventilate and prevent overheating.
Best Crops for Cold Frames in Winter
Stick to cold-hardy varieties that can tolerate light frost and cool temperatures. Top picks include:
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Leafy greens: Spinach, kale, arugula, lettuce (romaine and butterhead are hardier than loose-leaf), chard
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Herbs: Chives, parsley, thyme, rosemary (plant in containers inside the cold frame for easy access)
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Root veggies: Radishes, carrots, turnips (harvest small for tenderness)
2. Hoop Houses: Spacious Protection for Rows and Beds
Hoop houses (also called high tunnels) are larger than cold frames and cover entire garden rows or raised beds. They’re great for growers who want to protect more crops at once, and they’re surprisingly easy to assemble with PVC pipes or flexible metal hoops.
DIY Hoop House Setup (Under $100)
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Hoops: Use ½-inch or ¾-inch PVC pipes (10-12 feet long) or flexible metal conduit. Push each end 6-8 inches into the ground, spacing hoops 2-3 feet apart. The height should be 3-4 feet (tall enough to walk inside for harvesting).
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Cover: Drape 6mm clear plastic sheeting over the hoops, leaving extra material on the sides and ends. Secure the bottom edges with landscape staples, rocks, or soil to keep wind from lifting the plastic.
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End Walls: For extra insulation, add plastic sheeting to the ends (use zippers or Velcro for easy access) or leave one end open for ventilation. In extreme cold, layer a second sheet of plastic (with a 2-inch gap between layers) for better heat retention.
Bonus hack: Use row cover fabric (instead of plastic) for milder winters—it’s breathable, prevents frost damage, and keeps pests out. For freezing temperatures, layer fabric under plastic for double protection.
Winter Crops for Hoop Houses
Hoop houses offer more space, so you can grow larger crops or denser plantings. Try these:
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Brassicas: Cabbage, broccoli, Brussels sprouts, cauliflower (choose cold-hardy varieties like ‘January King’ cabbage)
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Greens: Collards, mustard greens, mizuna (these thrive in cool weather and get sweeter after light frost)
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Perennials: Asparagus crowns (protect young plants through their first winter) and rhubarb (cover to harvest earlier in spring)
3. Low Tunnels: Ultra-Simple Protection for Individual Rows
Low tunnels (also called row tunnels) are the most budget-friendly and easiest to install—perfect for beginners or gardeners with limited space. They’re basically small hoops covered with fabric or plastic, designed to protect individual rows of crops.
Building Low Tunnels (Under $20 per Row)
You don’t need power tools or complex materials—here’s how to do it:
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Hoops: Use flexible metal hoops (pre-made or cut from conduit), bamboo poles, or even sturdy wire hangers (bent into arcs). Space hoops 1-2 feet apart, pushing the ends into the soil so the tunnel is 12-18 inches tall.
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Cover: Drape row cover fabric (lightweight for mild frost, heavyweight for freezing temps) or thin plastic sheeting over the hoops. Secure the edges with soil, rocks, or small stakes.
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Maintenance: Check daily—on sunny days, lift the cover slightly to let in air and prevent overheating. In heavy snow, brush off the cover to avoid crushing the tunnel.
Low tunnels are great for extending the season for quick-growing crops like lettuce and radishes, and they can also protect seedlings in early spring or late fall.
Pro Tips for Year-Round Harvests in Cold Weather
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Insulate the Soil: Add a 2-3 inch layer of mulch (straw, leaves, or compost) around crops to retain soil heat and prevent freezing.
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Water Wisely: Water during the day (when temperatures are above freezing) to avoid ice buildup. Use room-temperature water if possible—cold water can shock roots.
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Choose the Right Varieties: Look for “cold-hardy” or “winter” varieties—seed packets often label these explicitly. Heirloom varieties are sometimes more resilient than hybrids.
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Rotate Crops: Even in winter, rotate crops to prevent soil depletion and pest buildup. For example, follow greens with root veggies, and vice versa.
Final Thoughts
You don’t need a fancy greenhouse to grow food year-round. Cold frames, hoop houses, and low tunnels are affordable, easy to build, and effective at protecting crops from cold weather. With a little planning and these simple structures, you can enjoy fresh, homegrown greens, herbs, and veggies even when snow is on the ground.
Whether you’re a beginner or an experienced gardener, these DIY setups will help you make the most of your garden space and extend your harvesting season—one frost-resistant crop at a time.
