High tech Year-round greenhouses recycle water and control temperature, CO2 levels and air flow
Albert Cramer used to get up every morning to milk cows at his dairy farm near Thunder Bay, Ontario. These days he’s tending cucumbers and peppers near Medicine Hat.
“I always liked the plant side of farming better than livestock,” he says. “I enjoy managing plants and this is a very hands-on business. And, like any other farming venture you need more and more growing area.”
Cramer began his farming career as a dairy producer but wanted something a little less demanding that still involved growing things. He picked a greenhouse operation and moved to the Medicine Hat area in 1985. “We had no computer in that first greenhouse,” he says. “Everything was manual. But, it was much smaller, so it was easier. It’s no different from any other kind of farming, you have to get bigger to stay in business.”
Cramer, his two sons and son-in-law run two greenhouses, one 7.5 acres and another newer one of about 10 acres. In the older greenhouse, they grow English cucumbers and red, yellow, orange and mini-peppers. In the new range they grow only English cucumbers and mini-cukes.
The new greenhouse has glass rather than plastic for better light transmission and it has a lighting system that allows him and his partners to grow year round. The main challenge of winter is inadequate light for summer crops. Lights are set for 18 hours light and six hours dark. Cold weather can still be a challenge for greenhouse operators as cool spots in the outer parts of the house can drop below 12 C and stress the plants.
“We like the heat the high-pressure sodium lights give off,” says Cramer. “But we use lots of natural gas as well.”
The new greenhouse also has a roof curtain system made of a special woven fabric that breathes but retains heat.
Commercial greenhouses don’t use soil as a growing medium anymore. They use coco peat, made from coconut husks. It’s a byproduct of the coconut industry that’s heat treated, washed and screened before shipping from Sri Lanka. The compressed bales expand to 15 l per kg when water is added. The peat can also contain a beneficial fungus that fights plant pathogens like pythium.
As much as 50 per cent of the nutrient solution leaches through the growing medium and is recycled. Water that condenses on the roof and from rain is also recycled.
“The water flow off the glass roof is better than off plastic, too,” says Cramer. “All the water runs into a little pond outside, we pipe it back in, adjust the nutrients and run it back through the irrigation system.”
Controlling pests and disease is a continual challenge in a greenhouse, although controlling temperature, CO2 levels and air flow help.
“We scout, scout and scout some more,” says Cramer. “We try to train everybody to watch for signs of pests or disease and manage to control them. The natural enemies and predators work well, so we don’t spray insecticides. We do have to watch for mildew. It’s the worst disease problem in cucumbers.”
With almost perfect growing conditions, cucumbers and peppers have to be picked every day. Greenhouse operators in the Medicine Hat area can’t get enough local workers to do the repetitive work of tying up plants and picking fruit. Cramer has 44 temporary foreign workers, mostly Thais and some Filipinos.
“We couldn’t do it without them,” he says. “They’re good, very dependable workers and they like the work. We’ve been able to renew them for up to four years, but it’s a huge amount of paperwork and dealing with the bureaucracy. It’s not always simple. Dealing with the language barrier can be demanding, especially in training.”
Despite all the high-tech systems in the newest of greenhouses, winter production is only about 80 per cent of summer yields. But, winter prices are higher. In the summer greater demand for salads boosts demands and that can help prices too. “As soon as barbecue season hits, demand goes right up,” says Cramer.