Last summer I began looking for a way to extend my growing season and did not want to spend much money, and I happened across Eliot Coleman’s book The New Organic Grower’s Handbook.
I also combed the internet for various articles, plans, etc. and happened across several resources.
Using what I had discovered in my research, I went about the process of designing my own. Here are the basic criteria I used in design:
- Size- basically a 10′ x 12′ will cover three of my wide beds for 12 feet.
- Needs to be light enough to be portable, heavy enough to withstand moderate to high winds.
- Needs to move in basically one-piece, not disassembled.
- Needs to be cost effective–shooting for $100-125 dollars.
- Can be assembled with a minimal amount of tools/and no power tools.
- Can be assembled without assistance (though assistance will be needed for moving)
- Can withstand the elements for several growing seasons
So here is the materials list:
5- 20 ft 3/4 inch PVC pipe
2 – 2″ x 6″ x 12 feet lumber
2- 2″ x 6″ x 10 feet lumber
20 conduit/pipe hangers
Poly Sheeting (not greenhouse grade) 14 feet wide in 100 ft roll (6 mm)
1- 12 foot piece of 1″ x 2″ furring strip for a ridge poll
Duct tape
Greenhouse plastic lath strips for anchoring poly to wood
Stanley (or other brand) all purpose clamps for attaching poly to PVC pipes
Nails- 20 penny nails for 2″ x 6″/and roofing nail for holding clamps,
staple gun and staple
Basic Instuctions:1) Create a 10′ x 12′ rectangle with lumber
2) Attach conduit clamps for PVC pipe along the length of the long sides of the rectangle. 3 foot centers, 2 clamps for each side= 20 separate clamps. (use woods screws rather than roofing nails for better support–but costs a bit more and recommend using an electric screwdriver)
3) A 20 foot piece of PVC bent over the 10 foot span will give you a height of about 7.5 feet in the middle of the hoophouse. Put an end in each of the parallel conduit clamps. You now have the basic frame for the hoop house. Materials cost is about $45-50 dollars for the basic frame.
4) Slide poly sheeting over the frame. Cut about 21 feet off the 100 ft. roll. This will give you about 6 inches slack on either side of the and about 1 foot of slack on either end. (Poly cost about $60 dollars from an online wholesaler with shipping. I figure I used about 1/3 of the roll for the whole house–cost=$20 dollars)
5) Anchor the poly to the wood with the plastic lath tape using a staple gun. Two sets of staples ever foot seemed to hold the cover well all winter. Lath tape was bought from a greenhouse wholesaler for abou $8 dollars. I used about 1/5 of a roll (Cost=~$2 dollars of material)
6) Attach the ridge pole (about $4 dollars) with duct tape to the top ridge of the hoop house using the three foot centers as a guide. This keeps the hoops in place and adds to the stability of the hoop house)
7) Stretch the poly and use the all purpose clamps to attach to PVC pipe (the clamps cost about $8 dollars for a dozen–two packages have done the job with some to spare. ($16 dollars)
8)- Cut end pieces of poly–I cut a 10 foot piece off the roll and then cut it in half to cover each end)..attach with the all purpose clamps. i cut a slit in one end for a door.
9) Move hoop house to desired portion of garden.
10) Monitor heat, ground moisture, etc.
Some basic information:
Total cost- With nails and other miscellaneous items…I figure the hoophouse cost just under $100 dollars.
Time to construct- about 3 hours total (someone with more construction talent could do it in less)
Temperature increase- with both ends on and the sun shining, I could expect 10-20 degrees difference between outside air temperature and inside (on a 50 degree day, it was not uncommon to see the temperature clib to 70-75 degrees. on a 30 degree day/45-50 degrees inside
Overnight difference- after dark, the hoophouse would usually be 4-5 degrees different on the inside. Many nights when I would wake up to frost, the temperature would be hovering around freezing inside. When I used row covering on the inside of the hoophouse, I could generally keep plants 4-6 degrees above the outside plants.
High winds/snow/etc.- This hoophouse saw some serious weather conditions this winter. Winds gusting to 50 mph, 4-6 inches of snow, torrential rain and temperatures falling to 0 degrees. It withstood them all (though most of the plants gave up the ghost in the coldest of temperatures), and all for about $100 dollars.
I have learned a few things in this first winter about growing conditions, etc. I am certain that I will be able to make some improvements to the construction and design as well.
It was a good investment and a fun project to monitor. Next year should be more productive.