When you’re supplying day-length sensitive plants to plant-hungry markets in New England, you need a light deprivation system you can rely on.
Matt and Martin Griswold, owners of Judges Farm in Old Lyme Connecticut, found what they were looking for in a light deprivation system they purchased from Advancing Alternatives in Lancaster, Pennsylvania.
Judges Farm grows annuals and perennials in the ground and in various hoop houses on 12 acres of land near the mouth of the Connecticut River. But it’s the Montauk daisies, asters, and mums that require a regimented dark period to set buds and bloom.
To meet this requirement the Griswold brothers installed Advancing Alternative’s automated blackout fabric across a 170 X 24’ greenhouse that sits on family property that dates back to the 1700s. The solutions, including curtains, motors, and controls were provided by Matt Krum, Strategic Account Manager at Advancing Alternatives.
“It’s been a great system,” says Martin Griswold. “The fabric is nice and thick, the controls are easy to set, the motors are reliable and the switches are all good. A little timer controls the up and down movement, pretty fail-proof and simplistic, we like that.”
Staggering the crop
They begin using the system in early July when the days are still pretty long.
“Because we don’t have a lot of room in the greenhouse we push in one crop and pull out another,” says Griswold. “We stagger the crops, putting things in at a certain time and pulling them out before they’re blooming: at that point, they’ve set buds and are ready to go.”
Griswold says when they first start using the system in mid-summer they set the curtains to draw down the fabric at 4:00 a.m. and open again at 9:00 a.m. As summer starts to draw to a close and the days get shorter they can “dial it down.” The main thing, he says, is that they achieve 12 hours of total darkness.
The roll bars that the fabric wraps around can be problematic at times for growers. However, Griswold is quite pleased with the roll bar that comes with the Advancing Alternatives system.
“They sell a nice aluminum extrusion that secures the blackout fabric to the roll-up bar with some wiggle wire. For wind control, we used ¼ inch nylon wind rope that comes from the peak down to the baseboard and back up making a “V” as you run down the house,” says Griswold. “It stops the blackout from billowing. In the winter we roll the blackout all the way up to the peak and put our clear poly over the top. The extrusion sandwiches the fabric to the bar.” He says, some vendors use clips instead of the aluminum extrusion.
Modifications before installation
According to Matt Krum at Advancing Alternatives, modifications aren’t needed to most greenhouses before installing a light deprivation system. However, some modifications were necessary for the 170-foot structure at Judges Farm due to a dip in the middle of the greenhouse.
“Judges was an exceptional case where the 170’ long structure was not level and even compromised by a damaged arch,” says Krum. Our system, which is typically retrofitted to existing structures, performed well and achieved light deprivation for Judges despite the challenges.”
One of the modifications they made to the 170-foot structure was to install a new double wire lock extrusion along the top ridge. Griswold says the blackout fabric is in two pieces, both secured at the peak and cover to the baseboard.
“So we had to put a new extrusion up at the peak of the house, on the outside, to secure each long edge of the blackout fabric,” says Griswold.
The second modification they made was at each end of the greenhouse. They installed a 4-foot section of blackout material that helps make the transition between the roof and the wall. Griswold says it blocks out a small amount of light and can remain in place year-round.
Lastly, because of the dip, which is about 9 inches, the curtain comes nearly to rest on the surface of the ground on both ends of the greenhouse before it does so in the middle. The installation crew used a 2X9 to build up the baseboard and close the gap. Griswold says with the modifications in place, it will be much easier to replace the fabric in the future.
Light deprivation system for hemp
The external light deprivation system Advancing Alternatives has developed and the Griswolds are using provides a much better value than the internal systems some companies offer. Hemp and legal cannabis growers prefer Advancing Alternative’s automated light deprivation system for a number of reasons, including the fact that it is installed on the outside of a greenhouse or hoop house and doesn’t take up space needed to grow the maximum amount of product.
There are also fewer moving parts with an external system, reducing the risk of malfunction and also the cost of installation. An internal system with the curtains hung on the inside of a greenhouse takes up precious space, increases shadowing and can limit what you can do with your grow lights. Such factors can be critical in hemp, and most other growing situations.
One of the major features of Advancing Alternatives’ light deprivation system is a two-layer, inflated perimeter light seal that creates an air “pillow” putting pressure against the curtain, assuring total darkness within the greenhouse.
It also comes with a strong, internally-spliced, 2” diameter roll bar that helps to reduce droops and shadows. Easy-to-program timed controls by the AegisTEC line of controllers will coordinate light deprivation with other heating and cooling systems.
When all was said and done the Griswolds are satisfied customers.
“It’s amazing how black it is inside,” says Griswold. “You need a flashlight to see where you’re walking.”
”Reaching out to Advancing Alternatives, that’s the first person I would call again if I had another project,” he says. “Great customer response, good product. There are probably other vendors out there, but the product and service are what has kept us happy and coming back for more.”
In addition to light deprivation systems, Advancing Alternatives sells environmental and solar-powered controllers, vent drives and ventilation curtains and a full array of greenhouse supplies and accessories.