Tuesday, January 11, 2011

Hoop House, High Tunnel, Polytunnel

Extend Your Growing Season

We love growing our own vegetables, and most important is that we control the quality of our food. Our soil, the organic and heirloom seeds, and chemical-free vegetables we harvest is what we are about.

After gathering and canning all the peppers from the plants last fall, I noticed at the end of October that buds were forming on several of the pepper plants. What a shame that Mr. Frost would soon take its toll on these. There was not much I could do at that point, but I could plan for next year! Our goal was to extend our spring and fall growing season, but do so economically.

Low tunnel, high tunnel, hoop house, polytunnel... are similar terms. It is a kind of greenhouse that can be made into various sizes, depending upon the space available, using some form of hoop, a plastic cover and whose source of heat and light is the sun. It is comprised of a frame, end walls, side walls, and a cover.

Much has been written and is available on the internet, from those made of PVC (polyvinyl chloride) to ones using a steel metal frame. Here are plans for constructing a Simple PVC High Tunnel from Kansas and Missouri authors and this from the University of Kentucky on High Tunnels.

Our circumstances and considerations included:

Location and space (geography): limiting for us is level ground, coupled with a sunny southern exposure in an open area, so options were few and the decision was made rather quickly. Coincidentally, it was not far from our potting shed. The space would allow a maximum size, 12 feet x 20 feet, and we would have to bring in a yard or two of soil in order to make it slightly more level.
: for this project, the low tunnel was not an option since we wanted to walk upright.
Strength and durability: occasional winter storms bring high winds from the coast, and with our extremely rocky soil, we would anchor all metal stubs in cement before attaching the steel bows.
Planned usage: we decided upon in-ground plantings with two raised beds on the west side to include salad greens, spinach, kale, broccoli, cabbage, cauliflower... On the opposite side would be a raised work table for seedlings and an area for planting a favorite heirloom tomato, 1 or 2 pepper plants, an eggplant, and anything else we might be able to squeeze in.
Affordability: a large beautiful greenhouse would be wonderful, but too expensive. Keeping within a budget is always a priority.

Neither my husband nor I have any background in construction or engineering, but we do possess common sense, logic, can read and follow directions (most of the time), and are patient (well, that is in degrees also... ). We have seen examples of hoop houses, and with all the information available from the internet, we knew we could do this. It might not be perfect, but it would serve our purpose.

We bought the steel anchoring stubs, the 17 gauge bent steel bows and greenhouse-grade polyethylene from a supplier, but everything else was purchased at our local lumber and hardware store.

The north end wall was done in plywood, but the south end was framed and covered in poly. I wanted to be sure we had as much light as possible from the southern exposure in order to compensate for our cloudy rainy days here in the Pacific Northwest.

Some adjustments will have to be made as temperatures begin to warm and stabilize. The fixed lower side walls will be undone and replaced with a roll-up device in order to ventilate and regulate the temperature of the summer months.

If you are considering constructing a hoop house of any kind, be sure to sit down and discuss your needs, make a plan, read and research before you begin.

We gardeners are an optimistic lot, always looking forward and preparing for the next spring, a new season of growth, and doing what is best for the health of our families.