- VP Growing Operations
- Head Grower Strawberries, Australia
- Growing Manager for Hydroponic strawberry producer
- Farm Manager Costa Rica
- Regional Sales Manager Fresh Produce
- Head Grower Strawberries, Norway
- Export Trade Manager
- Business Developer - Northern Europe
- Orchard Sector Manager
US (MT): Insulating greenhouses for the winter
The SIFT farm under snow in early November. Photo: NCAT
Winter got an early start in Butte this year. We have barely stepped into November and the ground is already blanketed in snow and there have been temperatures below 0°F. The greenhouse has been able to hold the inside air temperature around 30°F warmer than the outside on days with clear skies. Cloud cover depletes the solar energy needed to heat the greenhouse, making it difficult to hold in the heat. Last year, the freestanding greenhouse held to 1°F on a morning that fell below -30°F. Though this temperature is well below the capabilities of growing produce, there is significant potential to keep the inside of the structure above freezing with a small input of heat.
The growers have added extra insulation on the back walls of the freestanding greenhouse by using water-heater covers to keep the colder, north side from cooling the building. As well, they have hung blankets on the front that can be drawn back during the day to let light in and closed at night to keep heat in. As a final defense, they have used a poly film to drape over trays of microgreens and lettuce so that below-freezing air does not settle onto the plants.
SIFT are looking at ways to supplement light and heat that will not significantly increase inputs. One option is to find a way to use solar panels to charge a battery that can run small lights and a heater. An oil heater may be the next best option; however, they want to hold true to their objective of sustainability.
The other greenhouse is attached to the south side of the building, from which it receives residual heat. Though this area has not shown to operate effectively throughout the winter, it still holds quite a bit warmer than the freestanding greenhouse. Hardy mint and herbs are currently growing in here and have survived all of the weather we have gotten. One potential for this greenhouse is an area that recesses in the back corner. This area does not receive much direct light and will need to be supplemented with lights.
The plan is to build a microgreen stand that can operate off of fluorescent lights. Microgreens do not need much solar energy because most of their energy comes from the seed itself. They are also looking into using a sodium lamp or a metal halide light for larger plants. Low-pressure sodium lamps give off a red hue that is effective for mature, fruiting plants. The reddish light simulates fall sunlight when the sunlight comes in at an angle to the atmosphere. On the other hand, metal halide lights give off a bluer hue that simulates the direct light during summer. The combination of these allows for a wide spectrum of light to infiltrate the plants leaves and stimulate rapid growth.
Receive the daily newsletter in your email for free | Click here
Other news in this sector:
- 2023-09-29 Indoor-grown leafy greens brand surpasses traditional field-grown brands
- 2023-09-29 US companies announce collaboration on expected greenhouse project
- 2023-09-29 “We are constantly trialing 200+ snacking vegetable varieties”
- 2023-09-29 Double inflated plastic solutions shown at Fruit Attraction
- 2023-09-29 US: U of I hopes a new greenhouse will be an incubator for bioenergy crops
- 2023-09-28 22-hectare greenhouse in Mongolia to be completed by the end of the year
- 2023-09-27 Providing a unique greenhouse experience and launch of new sweet pepper variety
- 2023-09-27 Foil greenhouse lets Belgian strawberry grower expand
- 2023-09-25 Greenhouse Cluster Development project is way in Georgia
- 2023-09-22 CAN: Horticultural center topped with roof informed by Fibonacci spirals
- 2023-09-21 Ukrainian farmers receive subsidies to develop the construction of gardens and greenhouses
- 2023-09-21 Greenhouse farming in the Mogilev region is switching to new technologies
- 2023-09-21 Far North grower forced to diversify crops due to strawberry shortage
- 2023-09-20 Lettuce industry Florida expands into new production systems
- 2023-09-20 Ukraine: Ivano-Frankivsk community are establishing a greenhouse farm
- 2023-09-20 Low- and mid-tech greenhouse constructions ready for assembly
- 2023-09-19 China: New glass greenhouse are under construction in Beijing
- 2023-09-18 Environmental association points out flaws in greenhouse expansion plan
- 2023-09-15 NL: Bejo's new plant nursery officially opened
- 2023-09-14 Philippines: Korean funded greenhouses set for turnover by November