6 Best Clear Tarps For Cold Frames That Extend Your Growing Season
Extend your harvest with a clear cold frame tarp. Our review of the top 6 options covers key factors like durability, light transmission, and weather protection.
A well-built cold frame can feel like a superpower, letting you cheat the seasons by a few precious weeks on either end. But the frame itself is just the skeleton; the skin is what truly makes it work. Choosing the right clear tarp is the difference between a thriving bed of winter greens and a soggy, wind-torn mess.
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Why Use a Tarp Instead of Plastic Sheeting?
It’s tempting to grab a cheap roll of plastic sheeting from the hardware store, but that’s a classic rookie mistake. That thin plastic will shred in the first serious windstorm, leaving your plants exposed. It also degrades quickly under UV light, becoming brittle and yellowed in a single season.
A proper tarp, on the other hand, is built for the job. It has reinforced edges that resist tearing and, most importantly, grommets for securely tying it down. This isn’t just about convenience; a flapping cover can damage tender seedlings and let cold air rush in, defeating the entire purpose of the cold frame. Think of a tarp as an investment in reliability.
Xpose Safety Tarp: Top Heavy-Duty Choice
When you need a tarp that can take a beating, the Xpose Safety line is where you look. These are typically thick, often in the 10 to 14 mil range, with heavily reinforced corners and rope-lined hems. This isn’t a flimsy piece of plastic; it has a substantial feel that inspires confidence.
This is the tarp you choose for a permanent or semi-permanent cold frame that will face sleet, wind, and maybe even a bit of snow load. It’s overkill for a small, temporary setup you plan to move around, as the weight can be a factor. But if you’re building something to last, the extra thickness and robust construction mean you won’t be replacing it next year.
Farm Plastic Supply Film: Best UV Protection
Sunlight gives life, but it also destroys plastic. The UV inhibitors in a dedicated greenhouse film, like those from Farm Plastic Supply, are its most important feature for long-term use. Without this protection, a clear cover will cloud up, reduce light transmission, and eventually fall apart.
While often sold as a "film" rather than a "tarp," this material is specifically engineered for growing. It provides excellent light clarity and is designed to last for multiple seasons, not just a few months. If your cold frame is in a location that gets blasted by the sun all day, investing in a UV-stabilized film will pay for itself in longevity and better plant health.
Kotap Clear Poly Tarp: Lightweight Option
Not every cold frame needs to be a fortress. Sometimes you just need a simple, effective cover that’s easy to handle. The Kotap clear tarps are a great lightweight option for smaller frames, temporary row covers, or situations where you’ll be removing the cover frequently on sunny days.
The tradeoff for being lightweight is, of course, durability. A thinner 5 or 6 mil tarp won’t stand up to the same abuse as a heavy-duty one. But for a sheltered location or a short-term project, it’s a perfectly practical choice. It’s easy to fold, store, and deploy without a fight.
A-TARP Reinforced Tarp: For Harsh Weather
If you live where the wind howls and hailstorms are a real possibility, you need something with extra reinforcement. A-TARP and similar brands often feature a rip-stop design, with a grid of stronger threads woven into the material. You can usually see the faint checkerboard pattern if you hold it up to the light.
This grid is crucial. If a puncture does occur from a falling branch or a piece of hail, the tear is contained to a single small square instead of ripping across the entire tarp. This feature, combined with heavy-duty grommets and thick material, makes it the go-to choice for anyone farming in an exposed, unpredictable climate. It’s your cold frame’s insurance policy against a bad storm.
Grizzly Tarps Clear Tarp: Budget-Friendly
Let’s be practical: sometimes you just need to get a cover on a frame without spending a lot of money. Grizzly Tarps and other budget-friendly brands fill this niche perfectly. They provide a basic, functional clear tarp that will get you through a season or two for a minimal investment.
You have to be realistic about what you’re getting. The grommets might be made of aluminum instead of rust-resistant brass, and the material will be on the thinner side. But for trying out a new cold frame design or covering a less critical crop, a budget tarp is a smart, low-risk way to get started.
Tarps Now Vinyl Tarp: Premium Durability
When you’re ready to move beyond standard polyethylene tarps, clear vinyl is the next step up. A heavy-duty vinyl tarp is a serious piece of equipment. It’s significantly thicker, more resistant to punctures and abrasion, and offers superior optical clarity compared to most poly tarps.
This is the material you choose for a long-term, high-performance cold frame or a small hoop house. It’s heavier and more expensive, but its lifespan is measured in many years, not just a season or two. A vinyl tarp is for the hobby farmer who has their system perfected and is ready for a permanent, crystal-clear solution.
Mil Thickness and Grommets: Key Features
When comparing tarps, two specifications matter most: mil thickness and grommets. Don’t get confused; a "mil" is not a millimeter. It’s a thousandth of an inch, so a 10 mil tarp is 0.010 inches thick. For a cold frame, anything under 5 mil is likely too flimsy for anything but the most temporary use. A 10-14 mil tarp is a solid, heavy-duty choice.
Grommets are the metal eyelets that let you tie the tarp down. Pay attention to two things:
- Material: Brass is better than aluminum because it won’t rust.
- Spacing: Grommets spaced every 18-24 inches provide more secure anchor points than those spaced 36 inches or more apart. This is critical in windy areas to prevent the tarp from catching air and tearing itself free.
Ultimately, the best tarp is the one that matches your climate, your budget, and the specific demands of your cold frame. Don’t just buy the thickest or the cheapest. Think about how much sun, wind, and snow it will face, and choose the tool that gives you the best chance of harvesting fresh greens when everyone else’s garden is dormant.
