Sigma 26

Sigma 26

Rated 4.9 out of 5 stars
12 Reviews

Approx Size: 10' × 26' × 7'

Bring the tropical heat of the Caribbean to your own backyard in the middle of winter. Enjoy your own micro-climate where you can grow sweet new fruits and flavorful vegetables beyond the limitations of the weather outdoors — a space where you can harvest, snack, or sit and feel wonderful among your plants.


Strong and spacious: long-lasting construction, weather-resistant materials, and roomy design.


  • Wind resistant up to 65 mph for those living in gusty climates.
  • Withstands a snow load of up to 3 feet (32 psf)
  • Made with a heavy-duty galvanized pipe frame and strong polycarbonate panels
  • Arched shape - so the wind, snow, and hail just slide off the sides. 
  • Extendable beyond 100ft - so you can expand your greenhouse when you're ready.
  • Maintenance-free means you have more time to focus on your garden. 
  • We offer a 5-year warranty because our greenhouse is heavy-duty and long-lasting.
Regular price $4,250 CAD
Regular price $4,650 CAD Save $400 Sale Sale price $4,250 CAD
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About Sigma 26

The Sigma 26 was designed with a focus on spaciousness and stability. This greenhouse is perfect for 3 or 4 seasons of growing, allowing you to harvest fresh fruits and vegetables well into the colder months. Our Sigma greenhouses are built to last, featuring a rounded design and creative construction that brings heavy-duty greenhouse engineering into your own backyard.

Exact size: 118.1 x 83.9 x 315.79 inches

The end-to-end airflow, spacious size, and high 7ft roof height make this a comfortable place to garden throughout the day.

The greenhouse comes with:

  • two doors
  • two manual windows
  • the option to install multiple windows.

The galvanized pipe frame is both rust-resistant and durable. In addition, the construction can withstand moderate to extreme weather conditions, ensuring your garden will stay safe and flourish throughout the seasons.

Snow Load Up To 32 psf (160 kg / m²)
32 psf (160 kg / m²) is equal to 3 feet fresh snow layer or 1.5 feet packed snow layer and is maintenance free in the winter More About PSF
Wind Resistant up to 65 mph (100 km/h)
Sturdy greenhouse construction that resists winds up to 65 mph (100 km/h)
Extendable & Customizable
This greenhouse can be extended with additional expansion kits
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Rated 4.9 out of 5 stars
Based on 12 reviews
Total 5 star reviews: 11 Total 4 star reviews: 1 Total 3 star reviews: 0 Total 2 star reviews: 0 Total 1 star reviews: 0
100%would recommend this product
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12 reviews
  • KW
    Kay W.
    Verified Buyer
    I recommend this product
    Rated 5 out of 5 stars
    8 months ago
    Thanks Planta greenhouse!

    I really appreciate having the greenhouse. It was a challenge to assemble, but very rewarding after completion. I planted from seeds and within 3 days, radish had popped up and within 1 week cucumber also came up from seeds. Now everything is growing with gusto and I have received so many compliments on the greenhouse. It has only been finished for 2 weeks and it's the end of August 2023. Thanks Planta greenhouse!

    PG Profile picture for Planta Greenhouses Canada
    Planta Greenhouses Canada
    8 months ago

    Hi Kay, we're delighted to hear that your greenhouse is thriving and that you've received compliments on it. 🌱🏡😊

  • KM
    Kevin M.
    Flag of United States
    Verified Buyer
    I recommend this product
    Location Arizona
    Rated 5 out of 5 stars
    2 years ago
    The stability of the greenhouse is really good even in the wind

    We installed our greenhouse in 2021 and right now we are starting the new garden for 2022, so we’re growing seeds and other plans that can’t handle the cold. I believe it will add to the times we can grow. With the heater we bought with the greenhouse we should be able to grow year round. The stability of the greenhouse is really good even in the wind. And we had snow just this week (February) and it is holding up perfectly.

    My buying experience from Planta was good. It was challenging but rewarding to work through the instructions and also follow online video instructions for putting the greenhouse together. I’d recommend using both the paper manuals and online step by step videos when putting it together. If possible, have more than one person to construct the greenhouse. I was able to do it by myself but I’m sure it took quite a bit longer.

  • H
    Flag of United States
    Verified Buyer
    I recommend this product
    Location Kansas
    Rated 5 out of 5 stars
    2 years ago
    It is standing up to our harsh Kansas weather very well!

    I installed planta greenhouse in 2021 & I grow houseplants, tomatoes, and peppers. I will also be starting seeds. With a greenhouse, I will be able to start veggies early and keep growing some all year round. What I love most about my greenhouse is that it is always a sunny, warm place to hang out. I can have more outdoor plants without having to let them freeze or find a place in the house for them during the winter. This green house is very durable. It has already held up to our 80 mph winds in Kansas.

    I am so happy to report it is standing up to our harsh Kansas weather very well!!

  • PW
    Paul W.
    Flag of United States
    Verified Buyer
    I recommend this product
    Location South Carolina
    Rated 5 out of 5 stars
    2 years ago
    Good engineering and design

    I installed my Planta Greenhouse from Dec 2021 to Jan 2022 and I grow seedlings and flowers. The greenhouse helped to get planting started earlier and end later in the seasons.

    My experience buying from Planta was very good, no issues. The greenhouse itself has good engineering and design.

    To someone considering buying a Planta Greenhouse, I would say – Planta has the best selection. Get your land level as soon as you can before starting and take your time putting it together.

  • CO
    Colt O.
    Flag of Canada
    Verified Buyer
    I recommend this product
    Location Saskatchewan
    Rated 5 out of 5 stars
    2 years ago
    It helped keep plants safe in our heavy winds

    We installed our Planta Greenhouse in 2021. I have been growing tomatoes, lettuce, gourds, pumpkins, and papaya. So far, it extended our growing season and helped keep plants safe in our heavy winds.

    Our experience buying from Planta was easy, if anything was wrong or missing the customer service team looked after this right away.

    To someone considering buying a Planta Greenhouse, I would say – Go bigger at the beginning. It’s much easier than expanding. The greenhouse was easy to build once you understood the instructions. Lastly, I recommend the windows that open with temperatures for sure.

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Sigma 26 ships in these boxes:

  L, (in) W, (in) H, (in) Weight, (lbs) Quantity
Sigma Base 1 62 11 3 46 1
Sigma Base 2 77 23 3 92 1
Sigma Polycarbonate Base 83 44 3 55 1
Sigma Extension 77 17 3 58 2
Sigma Polycarbonate Extension 83 44 2 20 3


Greenhouses are amazing products, and they require special shipping and handling. That is the reason, we have been working diligently over the past year to secure preferential shipping rates for our customers. Most shipments across Canada and the US are between $250 and $450. 

  • We will contact you to confirm shipping price, based on your location and order size.
  • Shipping on most residential greenhouse orders is between $250 and $450, customers in remote areas may need to pay extra.
  • When you place your order, please make sure to enter the correct Phone and Address at checkout. You will be contacted by phone before the item is shipped. We cannot be responsible for deliveries to incorrect addresses.
  • As part of the delivery process, we require a contactable telephone number (for the courier company to contact you) before the item is shipped.
  • White glove delivery service isn't available. The greenhouse components are delivered in multiple boxes, the largest of which weighs 80lbs. The greenhouse will be delivered to your driveway. Please make arrangements to have the package moved to its installation location. 
  • We do not ship to PO Boxes, as in most cases you will need to sign for your item.  
  • Orders placed on weekends or public holidays will not begin processing until the next business day.