6 Lessons Learned from a Mini Hoop House Experiment

In preparing to build my first hoophouse a disproportionate amount of time was spent searching the internet in regards to building the best hoop house for my needs. Nobody seemed to construct a simple hoop house tall enough for my vision, and some were way too complicated . In the end I chose my own dimensions and just made it work. This was an experiment after all, a form of research and development that taught me many things.

The hoop house was located in a sunny spot in a south facing meadow. It receives some of the first morning light and the last of the afternoon sun, so about 11-12 hours of direct sunlight in the summer and about 9 to 10 hours on the fall equinox, in other words plenty of direct sunlight. This is the area where our 2018 MCRSA licensed medical grow will be located soon enough, with luck.

Ready for hoops

For this experiment the square footage was kept small basically 8' x 10'. The logic being start small, do it right, and then scale up later. Once the spot was situated, the ground was loosened and all the grass and weeds were removed and thrown into the compost pile. Next some salvaged 2”x8” boards were nailed together to form the base, really simple easy construction. Then, following the chosen internet instructions numerous pieces of  3/8’ rebar cut to about 2.5’ long were pounded a foot or so into the ground. The rebar was strategically positioned along the 10’ side at 2 foot intervals. So a total of 12 rebar stakes were put into the ground, 6 on each side, to support the PVC hoops. Easy enough.

Next the 20’ long 1” PVC pipes were placed along the frame. One side of the pipe was fitted over the rebar and bent to fit the corresponding rebar on the opposite frame board. Soon enough there were six hoops around and above the frame. This is when the vision of your plan comes to life you will see the skeleton of the structure. Next two basic end walls were built with left over 2x4 wood and the hoop house was ready for the plastic sheeting.

Ready for sheeting

The sheeting was put on by just myself, but it is recommended to have one other person help you. Try not to do it on a windy day, however it can be done solo on a blustery day like this one was depending on your skill and ingenuity. The plastic was attached to the frame base on 3 sides and left loosely attached at the entrance. Overall this project took about 8 total hours including the hardest part of loosening the dirt and weeding. The result is a great heat trapping finished product. It is a tiny 84.5 square feet of space with a 7’ high arch. The sidewalls were very steep just like the mind’s eye design.

Plants

The real experiment was seeing how the cannabis crop would respond to the internal conditions of the hoop house.  It was time to plant.  The garden was planted before the plastic sheeting covered the hoops. Four cannabis clones were planted in mounds of a popular potting soil on top of the loosened soil. A drip irrigation system consisting of four 2 gallon per minute bubblers were installed around each plant. The timer was set for 15 minutes every 3 days, which equates to 2 gallons of water every three days per plant, or about 20 gallons a month per plant. In other words it was very efficient water use. Inside the hoop it was about 25 degrees warmer than the outside air when completely closed. Let’s just say this location is not in valley heat.

Muggy and crowded

When retuning to the grow a few weeks later everything was looking good if a little humid. So it remained a closed hoop house. A few weeks later the plants were way bigger and starting to get crowded. The inside of the sheeting had condensation on it. Walking inside my sunglasses instantly fogged up. It felt like a muggy tropical jungle. The plants itself had an atypical branch structure for the “Cloudwatcher “ strain. The framework branches were ok but the secondary branches were realling stretching and super dense, just weirdness. The hoop house needed ventilation and water was dripping down from the interior roof and walls. It was a total rainforest. I felt a mildew time bomb in the making. The endwalls were opened up about half way but the sides were kept on lockdown. Within minutes the excess moisture evaporated out.

Harvest Time at the Experimental Hoop

Was it too late?? Yes it was. The endwall ventilation was not enough and admittedly the plants needed more babying and maintenance especially towards harvest. It was a busy summer. The standard maintenance techniques were neglected on the hoop house crop strictly due to the absence of the farmer. This year the garden was treated like a guerrilla grow which rarely gets visited. So live and learn, win some lose some, insert favorite cliche here….

6 Take Aways

1. Hoop houses trap heat and moisture very well and need not be complicated.
2. Side walls, not end walls need to be opened for adequate ventilation.
3. Don’t overcrowd plants and keep branches away from the sheeting.
4. Always schedule routine maintenance if you want a healthy harvest.
5. Visit plants more than once a month, and schedule more time during flowering not a 6-8 week gap at prime time (oops life got really busy this summer)
6. Go for it in cooler or foggier coastal locations and above all have fun with it.