Gardening: The Power of the Hoop

David

Almonte: Friday March 29, 2019: 10:00 AM: Outdoor temperature 2 C: Hoop House temperature 20 C. Happy gardeners were grabbing bags full of spinach for a super-early, super-local lunch. It was shirt-sleeve temperature and very comfortable. For me it was such an incredibly sensual experience to work with my hands in the soil and breathe in the scent of that rich fertile soil. The experience was all the better for being shared with several other like-minded gardeners.

At various times over the last four years I have reported on the gardening activities of a local gardening group of about 17 gardeners that has been testing the limits of how much we can reasonably extend the season for growing vegetables, by using a 1500 square-foot hoop house (basically an unheated green house).

The season for us started March 8 checking to see what vegetables survived the winter. Seven beds of spinach over-wintered beautifully. Both Bloomsdale Longstanding and Gusto Italia over-wintered well however we find the Gusto Italia is a more coarse plant, so Bloomsdale remains the variety of choice for over-wintering. Kale and claytonia also over-wintered relatively well.

In this, our fifth growing season, planting started on March 8. This compared very favourably with our experience of the last four years. In 2018 we started on March 9, in 2017 we started on March 10, in 2016 on March 11 and in 2015 on March 13.

On our beds, which are about thirty inches wide, larger vegetable get two rows per bed, smaller vegetables such as carrots and radishes get three rows. One technique we often use is to plant two rows of carrots on the outside of the bed with radishes in the middle row. The radishes are very quick to grow, being ready to harvest in a month, and are long gone by the time the carrots start to expand and need more growing space. So far we have been planting carrots, radishes, beets, lettuce and arugula.

As the following photo shows, radishes that were planted March 15 are thriving.

What is a Hoop House? It is basically an unheated greenhouse – a tunnel made of polyethylene usually semi-circular, square or elongated in shape. The interior heats up because incoming solar radiation from the sun warms plants, soil, and other things inside the building faster than heat can escape the structure. Air warmed by the heat from hot interior surfaces is retained in the building by the walls. The beds are covered with fabric in the colder weather to hold some heat in the soil.

The Hoop House cools down over the night until the inside temperatures are the same as the outside temperatures (although the soil temperature remains considerably warmer). The rapid build-up of heat on sunny days means that plants will benefit and grow faster but the reality is that without over-night heat in the Hoop House we are limited to plants that can tolerate cold temperatures. A big part of our learning experience is finding out which vegetables are appropriate for the early spring and late fall seasons.

Five years ago no one had even heard of Claytonia. It is probably the most cold-hardy vegetable grown. Claytonia perfoliata is a rosette-forming plant, growing to about six inches in height. The common name miner’s lettuce refers to its use by California Gold Rush miners who ate it to get their vitamin C to prevent scurvy. Most commonly it is eaten raw in salads, but it is not quite as delicate as lettuce. Sometimes it is boiled like spinach which it resembles in taste.

Our group of 16 enthusiastic gardeners (some experienced, some novice) was formed in 2015 as we learned about the potential to expand our gardening season as well as our gardening knowledge. This opportunity was created through the generosity of the owners of the Hoop House who determined it was no longer required for their use. Our Hoop House creates 1500 square feet of ‘indoor’ gardening space.

The garden has been operated as a collaborative garden – no gardener has an individual allotment. Most of the work gets done in a weekly Friday morning work party. Short meetings are generally a part of the work party as is coffee and a chance to socialize. Annual half-day planning sessions and pot-lucks have helped to solidify a team with shared goals. The organization is the antithesis of a hierarchical structure and has evolved with virtually no conflict as members have assumed roles over the year. In fact the need for meetings has become less and less as gardeners have assumed different roles and it becomes more and more obvious to the experienced gardeners what tasks need to be attended to.

One of the most important goals is to share food with the community. More than half of the produce is donated to the Lanark County Food Bank. A second goal is to advance our own gardening knowledge. This has been accomplished in spades as experienced gardeners share their knowledge and we all learn about the tremendous potential in extending our gardening season. A third goal is to document what we are doing so that we can share our experience and knowledge with others.