See our entire selection of DIY greenhouse kits, which require the purchase of local wood and metal, or shop our inventory of USA-made All-Metal Greenhouse Kits for complete kits. This kit will stand approximately 10.75' on the center.
10 |8.5
12 |8
16 | 9.5
20 |10.75
Greenhouse Building Instructions Here
*Not eligible for returns
Shop other DIY kit sizes here.
Shop complete kits here.
*Lumber choices may be limited by location. Redwood, cedar, or pressure-treated are the best choices for any structure that will be exposed to moisture.
Grew these for the past three years and I will keep growing them for many more. I highly recommend them. Great germination rate. Every onion grew to the size of baseballs and others a bit bigger and they store very well.Best long day onion I have ever grow.
I am very happy with my heirloom seeds. I cannot wait to germinate them.
Started my seeds on 12/31/25. I’ve had almost 100% germination and the onion seedlings are a couple of inches tall at this point (1/9/26). Looking forward to a great harvest!
Grew these last year, so I bought more seeds! they were awesome, very prolific and tasted great!!
I started them early....did waterjug winter seed starts .. they did very well....grew up to be nice sturdy plants, bearing lots of fruit! Thank You!!