Dealing with Canada’s Light-Pollution Laws

Chris Beytes

If you’re a greenhouse grower in Leamington or Kingsville, Ontario, and you run supplemental lighting at night, you already know about this: As of April 1, you face steep fines for light pollution unless you: 1) Shut off your lights after dark; or 2) install blackout curtains and keep them closed from one hour before sunset to one hour after sunrise (with some minor exceptions explained below).

We learned about this when we were asked to moderate a webinar March 8 for the ACT (Advancing Cultivation Technology) Summit. Growers from all over tuned in to the 75-minute session that featured Ton Habraken from Svensson, Paul Jense from Priva, and Dutch tomato grower Lars van Baar lending their expertise on how to grow under light-abatement curtains, which cause heat and humidity to build up at night, negatively impacting the crop.

One solution is “gapping,” or opening the curtain a small amount (5% to 10%) to vent the heat and humidity. Most rules, such as those that have been in effect in the Netherlands for a decade, allow a few hours of gapping during the night. Leamington’s new bylaw allows for 10% gapping between 2:00 and 6:00 a.m.,  however, the Kingsville bylaw, unfortunately, doesn’t allow any gapping. The photo shows two Dutch greenhouses—one with the light-abatement curtains fully closed, and one with a curtain gapped open 10%. The fabric used is Svensson’s Obscura.

What does this mean to you, seeing how you probably aren’t a Kingsville or Leamington grower? Well, we’ve heard that British Columbia and Quebec may be looking at similar rules. And other areas of North America and beyond with dense greenhouse production could face the same fate. Even standalone, rural operations can be impacted. Just ask Henry Huntington of lēf farms in Louden, New Hampshire, who dealt with the issue in 2018. GT