In Guelph, Ontario, grower Zach Loeks stores vegetables year-round with his award-winning, underground, cold storage facility. Through the winter, vegetables are held at just above freezing and with near-optimum humidity. By making a thousand ice blocks in the dead of winter, similar conditions are extended through the summer.
“We have 2 to 4 C temperatures the year round,” he told the Guelph Organic Conference Jan. 29.
Loeks, who with his partner Kylah Dobson, operate Rainbow Heritage Garden on 50 acres an hour west of Ottawa at Cobden, said farmers should consider the big picture before investing in cold storage. That includes developing a dependable market and growing unblemished produce harvested at peak maturity.
“A properly stored and grown winter carrot is far superior than to anything you buy in a regular grocery store.”
The 20 by 30 foot facility is divided into bays with ventilation to optimize storage conditions. Loeks hired an excavator to dig a hole into a hillside next to his garden and consulted with the local building inspector as plans were made. Drainage with a flush-out system was installed and footings poured.
The next step was to hire a crane to drop into place four concrete, pre-cast arches, the type of units that might be used individually for small stream crossings.
They needed to be strong to hold the 2 1/2 metres of earth that was placed on top. Loeks said that even with a 75 percent discount, the arches cost $4,000 each.
The back wall of the storage unit was built using reinforced cinder blocks placed under the rearmost arch. The front features plenty of insulation, a roof extension for shading and attractive cedar facing.
Customers come to him for special sale days, and they treat it as an outing. Many are as interested in the storage unit as they are the organic produce.
Loeks built a concrete floor, but he left a pair of 60 centimetre earthen strips running the length of the unit. Water used for washing can drain away through the strips or water can be added to increase humidity.
Water falling from the arches has not been an issue. Moisture does collect, but it runs along the inside curve rather than dripping.
Shelving was initially installed, but Loeks found that bagging the produce and piling it in a series of chambers was more effective. Carrots are stored at the back, and space is left for the ice blocks.
Loeks makes the blocks in plastic containers, which are used during the growing season to store vegetables. They’re of a size that can be easily lifted and also they need to be cleaned. Flexing the sides of the containers pops out the blocks.
An ice wall is gradually extended to fill the rear quarter of the storage, which is enough volume to keep the storage cool over the summer.
The inside summer temperature would be relatively cool even without the ice, thanks to the constant earth temperature. Loeks uses poly curtains to divide the storage into different temperature zones, the coldest being next to the ice.
Loeks and Dobson won one of the innovation awards presented by Ontario agriculture ministry in 2014.
