Polycarbonate Greenhouses for Sale

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A polycarbonate greenhouse is the practical choice for growing year-round. Multiwall polycarbonate panels insulate better than single glass, spread soft, even light over your plants, and shrug off hail. At Mulberry Greenhouses in Atlanta, GA we carry polycarbonate greenhouse kits from Hoklartherm Riga (Germany), Riverstone MONT (USA), KGT Hoklartherm and Cross Country (Canada), from compact 8'x7' kits to 14'x30' growing houses. Every kit ships free to mainland US addresses.

Polycarbonate Greenhouses for Sale: Compare the Models

Model Sizes Panels Best for
Hoklartherm Riga 8'x7' to 10'x18' 8mm twin-wall, 10mm ends Cold, snowy and windy areas; German-engineered arch that sheds snow
Hoklartherm Riga XL 14'x16' to 14'x30' 16mm triple-wall Serious winter growing, market gardens, schools
Riverstone MONT 8'x8' to 8'x24' 8mm twin-wall Made in the USA; expandable in 4' sections; Growers Edition and solar-vented Mojave Style packages
KGT Nelke 4 Pro 10'x14' 16mm triple-wall A classic A-frame four-season greenhouse with a wide 38" door
KGT Santini II About 10'x7' 16mm triple-wall Modern design; a greenhouse that doubles as lockable storage
KGT Linea II About 10'x7' 10mm twin-wall, or hybrid Small modern yards; the same compact footprint at a lower price
Cross Country Sunhaven 8'x8' 6mm twin-wall Made in Canada; rated for 32 psf snow and 85 mph wind

Twin-Wall or Triple-Wall Polycarbonate?

Multiwall polycarbonate works like a double-pane window: air trapped between the layers slows heat loss. The more layers and the thicker the panel, the warmer your greenhouse stays and the less you spend on heat.

  • Twin-wall (6mm to 10mm): two layers. A big step up from single glass or thin clear plastic, and enough for year-round growing in most of the US with a heater on the coldest nights. Riga, MONT, Linea II and Sunhaven use twin-wall.
  • Triple-wall (16mm): three layers and the best insulation we offer. Choose it for cold northern winters, high heating costs, or if you want to grow warm-season crops through winter. Riga XL, Nelke 4 Pro and Santini II use 16mm triple-wall.

Beware of "polycarbonate" kits with very thin single-layer panels. They are fine as season extenders but hold little heat. Every greenhouse on this page uses multiwall panels.

Polycarbonate vs Glass Greenhouse

  • Insulation: multiwall polycarbonate holds heat far better than single glass.
  • Light: polycarbonate diffuses sunlight, which reduces leaf scorch and hot spots. Glass gives crystal-clear views and maximum light.
  • Strength: polycarbonate is shatter-resistant and handles hail, falling branches and kids' balls well.
  • Weight and assembly: polycarbonate panels are light and easier to handle during the build.
  • Looks: glass wins for a classic, elegant look. See our glass greenhouses and Victorian greenhouses.

Want both? Hybrid greenhouses pair clear glass walls with an insulating polycarbonate roof that also cuts summer glare. Options include the Royal Victorian VI34, VI36 and VI46, the Janssens Gigant, the Cross Country Legacy 8'x8' and the Linea II Hybrid.

Shop Polycarbonate Greenhouses by Size

Our tip: buy one size larger than you think you need. Riga greenhouses cannot be extended later; MONT greenhouses can grow in 4' sections.

🌿 Why buy your polycarbonate greenhouse from Mulberry Greenhouses? We are a small, woman-owned business in Atlanta, GA, accredited by the BBB with an A+ rating, and an authorized Exaco dealer. We ship free to mainland US addresses, answer every question personally, and offer a Price Match Guarantee (please check the rules). Call 678-408-8222 and we will help you choose.

Polycarbonate Greenhouse FAQ

Is a polycarbonate greenhouse good for winter?

Yes. Multiwall polycarbonate is one of the best glazing choices for winter growing because it holds heat so well. For the coldest climates, choose 16mm triple-wall, and add a heater for hard freezes. Our guide on how to heat a greenhouse without electricity has more tips.

How long does polycarbonate last?

Quality multiwall panels have a UV-protective layer and typically last many years. Manufacturer warranties on our models run from 10 to 15 years on the panels, and the Cross Country Sunhaven carries a lifetime warranty. Check each product page for details.

Can you see through a polycarbonate greenhouse?

Multiwall polycarbonate is translucent rather than clear. You see light and shapes, not a sharp view. That diffused light is good for plants and adds privacy. If you want clear views, choose glass or a hybrid.

Does a polycarbonate greenhouse need a foundation?

It needs a level, solid base and should be anchored against wind. Riga and Nelke greenhouses offer a foundation frame you bury in a shallow trench; MONT greenhouses have an integrated base. Our greenhouse foundation guide covers every option.

Can I assemble a polycarbonate greenhouse kit myself?

Most handy homeowners can, with two or three people over a day or a weekend. Our assembly crews page lists crews past customers have used; we are not affiliated with any of them.

How is it delivered?

By freight truck, curbside. Shipping is free to mainland US addresses. Please let us know if your street cannot take a large truck.

Prices, availability and promotions can change at any time. Please check each product page for current pricing.