We built this hoop house for use last winter. It is built from PVC tubing and modular. We can take this down for warmer months. The plastic is special UV plastic for use in hoop houses. This design works very well for plants that grow well in cool weather but still need protection from frost. We had swiss chard well into late fall and we had kale throughout the winter. As the weather warmed up many plants we had started in this house matured earlier than they would have otherwise. These included cabbage, garlic, and the swiss chard returned early. We were also able to start sweet onions early. One mistake in this plan was apparent the first night it was in the garden. We did not weight it down properly and we had very strong winds that night. The entire hoop house blew over and landed upside down on the patio. The large bang it made woke us up. Therefore, we were in the garden at 2:00 am returning this to its place and searching for all the bricks, bags of mulch, and buckets full of water that we could find to hold it down. The next day we added large stakes to hold it to the garden.
The hoop house above worked so well that we decided to build a regular greenhouse this year. This is a temporary structure we designed and built from wood and plastic panel. This structure bolts together with four bolts. This makes it easy to move incase we need to, but heavy enough it will not blow away. The roof is also clear plastic and is hinged on the low side. This allows us to prop the roof open on the taller side for venting. We later added a door made of the same panel. The shelves are hardward mesh over wood. and bolted to the side. For anyone looking to start their own seeds, this type of structure is a great tool. This will save on gardening costs later since seeds are much cheaper than seedlings.