Approx Size: 10' × 26' × 7'
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:
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.
Bought Sima 2021 Euro a couple of years back. Got it assembled last year and finally got auto vents installed this spring. One vent cyl did not function, it would not collapse. I got in contact with Murad at Costumer Service and he assured me that even though the warranty had expired they would send along a replacement. Logistic Coordinator Paulette followed up and new cyl arrived and works great. Excellent service . Finishing the install of a bench and drip system. Looking forward to great growing results.
Thanks so much, Neil! We’re glad Murad and Paulette were able to help and that everything’s working smoothly now. Wishing you a fantastic growing season ahead!
We grow a variety of herbs, tomatoes, several types of peppers, peas and beans, onions, garlic, mint, starters, and squash plants. It’s been a learning experience, but the greenhouse is helping us extend our growing season. Last year, during a grasshopper infestation, we had to transplant surviving outdoor plants into the greenhouse, and it provided the protection we needed. We’re now working on converting it into a 4-season greenhouse.
Customer service was great and the product itself has performed well. We purchased the sunshade, which made a big difference. We also installed a trellis for vining plants and are currently working on setting up a heating and cooling system, along with purchasing greenhouse shelving.
What we appreciate most is the protection it provides from critters and the elements, along with its spacious design—perfect for raised beds. Our students are about to help clean it out and get started on early spring planting. If we had the funding, we would install another one. As a non-profit farm running a school program, we’re currently applying for a grant to cover electrical installation so we can move toward full 4-season use.
I installed our first greenhouse, a Sigma model, in late fall of 2024. While we haven’t started growing yet, we’re just now getting ready to use it. My wife plans to grow vegetables, flowers, herbs, and microgreens. We’re expecting earlier seedling starts and a longer growing season overall.
Buying from Planta was very easy. I did a lot of research beforehand and chose Planta for its combination of value and quality. Customer service has been great—a real person answers the phone! I called once with pre-purchase questions and twice more during assembly. Each time, my questions were answered clearly and promptly.
We placed the greenhouse on the east side of our barn to help protect it from strong summer storm winds. I poured a cement slab with a 4" curb and anchored two 2"x4" treated boards on top, giving the greenhouse an extra 7" of height. I also installed a lateral 5" drain in the floor to help with water flow.
My favorite thing about this greenhouse? It's a thing of beauty—and I bought it for my wife, who has always dreamed of having one. We’re both very happy with it and would highly recommend it. The combination of video guides, printed instructions, and the BILT app made installation easier than you’d think.
We installed our Planta Greenhouse in 2024, and it’s already made a huge difference in our gardening experience. This was our first greenhouse, and it allowed us to start the growing season much earlier than usual. Even in winter, the greenhouse stays warm enough to comfortably work inside on sunny days—something I never expected to enjoy so much. I was even able to harvest cucumbers into mid-October!
Inside, we’ve grown tomatoes, cucumbers, basil, and a variety of other herbs. To optimize the space, we built a solid wood foundation with raised garden beds and a concrete walkway between them. Gravel bedding and proper drainage around the structure have made it both functional and low-maintenance.
Buying the greenhouse from Planta was straightforward. We took advantage of a Christmas discount, which inspired us to make the purchase sooner than planned. Delivery was on time, and although installation was a bit time-consuming (as expected for a first-timer), the process went smoothly. I’m genuinely impressed with the quality and performance of this greenhouse—and I’m really enjoying it!
After moving twice in five years, we've now installed our third Planta greenhouse—this time a 26-foot Sigma model alongside extra polycarbonate panels, which we used to create a custom lean-to greenhouse against our garage. With each build, we’ve refined our setup process, learning how to make installation smoother and more efficient every time.
Our large greenhouse is dedicated to cabbages, broccoli, cauliflower, leeks, celeriac, and even a couple of grape varieties, with netting on the doors to help keep cabbage moths out. In our new lean-to space, we’re planning to grow tomatoes, peppers, squash, pumpkins, and cucumbers. We like to use grow bags for flexibility and continue to plant staples like potatoes, onions, and beans outdoors. Even our chicken coops benefit from leftover polycarbonate panels—adding natural light while keeping them warm and dry.
The Sigma greenhouse has truly improved our gardening experience. It’s helped us extend our growing season and grow varieties that normally wouldn’t thrive in our climate. Planta’s greenhouses are incredibly sturdy—ours held up through heavy snowfalls, and after experiencing some damage from Hurricane Fiona, we added L-brackets and longer screws for extra reinforcement. These little adjustments have made a big difference, especially for older hands during assembly.
Ordering from Planta is always a breeze. Their quality is unmatched, and the support team has consistently provided excellent service. That’s why we’ve returned…
| L, (in) | W, (in) | H, (in) | Weight, (lbs) | Quantity | |
| Sigma Base 1 | 80 | 11 | 4 | 93 | 1 |
| Sigma Base 2 | 78 | 24 | 3 | 93 | 1 |
| Sigma Polycarbonate Base | 82 | 44 | 4 | 58 | 1 |
| Sigma Extension | 78 | 21 | 3 | 63 | 2 |
| Sigma Polycarbonate Extension | 82 | 44 | 2 | 31 | 3 |
| Total weight: | 463 |
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.
