Few things are as appealing to the true gardener as the idea of fresh, homegrown produce through all four seasons of the year. In heavy snow states, such as those throughout the northern US, winter weather can be quite a challenge. However, with just a bit of planning and a snowproof greenhouse, you will reap the full benefit of winter greenhouse growing and continue to harvest what you like when the snow falls.
This article will prepare you with the knowledge and tips needed to take on the challenges of greenhouse winter protection in heavy snow states, focusing on three key areas: choosing the right heavy snow greenhouse structure, winter protection techniques you can institute, and selecting cold weather greenhouse plants for growing.
Winter Greenhouse Growing in Heavy Snow States
Understanding your specific winter growing zones is crucial when planning your winter greenhouse. Zones are based on the average minimum winter temperatures and states like New York, Michigan, and Maine fall into zones where winter temperatures often dip below freezing, posing significant challenges to plant growth.
Heavy snow greenhouse accumulation is a major concern for greenhouse structures. The weight of snow can lead to structural damage or even collapse. Choosing a greenhouse with a high greenhouse snow load capacity is essential for heavy snow regions.
Building a Snow Proof Greenhouse
Material & Structure
One has to be informed of a few models that would thrive well in harsh winter conditions whenever the choice of a greenhouse for heavy snowfall regions comes into play. The strength or type of the frame material used in greenhouses is what will determine whether it supports the amount of snow that falls. The greenhouses containing an aluminum or steel frame are stronger and more durable than those made of PVC or polycarbonate.
Because of the structural stability, freestanding greenhouses are recommended for regions with heavy snow. This type of freestanding greenhouse is more resistant to wind and snow damage when compared with attached structures. This is because the free-standing structure provides greater weight distribution, increasing its resistance to the elements of wind and snow. Secondly, a freestanding greenhouse will have more freedom in placement and orientation so that it can receive the best sunlight and ventilation, hence providing better winter greenhouse temperature control and functionality.
Foundation & Anchoring
Adequate preparation of the greenhouse for winter requires a strong anchoring system. One would do well to have at least a concrete perimeter foundation. This is quite an excellent way of distributing the weight of the greenhouse and the snow that might collect on it. Anchoring to the foundation using heavy-duty bolts is quite important to prevent wind uplift, which would cause some disastrous damage.
Another option would be the use of frost-protected shallow foundations. Such a foundation is specially designed to resist the occurrence of freezing and, therefore, can provide stability to your greenhouse during the winter months.
Roof Design
The design of the roof is extremely important when it comes to managing snow on a building. By strategically placing snow guards along the roof, the avalanche effects can be prevented. These guards regulate the flow and distribution of snow and prevent dangerous, sudden snow slides that can cause damage or injury.
The slope angle of the roof is another important consideration for greenhouse snow load capacity. The minimum slope angle should be 35 degrees to ensure easy removal of snow. This angle helps the snow slide off the roof more easily, and less effort is required to remove it manually.
Greenhouse Winter Protection Techniques
The proper greenhouse insulation techniques will help in keeping the greenhouse warm from the inside. Insulation under benches or walls will do the deal. Seal all the entry points properly to prevent the escape of heat and also hold the structure of the greenhouse intact in rough weather conditions.
Extra greenhouse winter protection can be given by anchoring a plastic tarp or dropping curtains to the side of the greenhouse. It needs to be loose enough that it can drop in one piece over the entire greenhouse. Once on, the cold air will be below the drop curtain and the added layer will be directly against the greenhouse cover, improving greenhouse heat retention. To prevent potential tear points, it may be of value to drop and place cardboard pieces at the tear hole.
Utilizing shade cloths can minimize heat loss, as they can help with winter greenhouse temperature control. Greenhouses with solid, average R-Factor, or inflated double-layered polyethylene are good choices, with single-layer polyethylene with inflation being the best value. For houses in areas with harsher weather conditions, materials like tempered glass or silicone insulating panels are the longest-lasting options.
In addition to affecting the greenhouse envelope, remember to make the right decisions to help control humidity levels and prevent problems from occurring due to temperature fluctuations. On sunny days, a mini-split HVAC system can stand out for winter greenhouse temperature control and the possibility of increasing CO2 in the greenhouse. It is also beneficial to consider employing generator appliances in the greenhouse, as they can help to pipe in carbon dioxide during daylight hours.
There are also various systems, such as fan, pad, mini, and wick systems, that can help to create a good balance between maintaining optimal humidity levels and ventilating excess moisture in the greenhouse. It is important to consider the greenhouse design and crop mix when selecting which system is best for your specific needs.
Frost Protection for Greenhouses
Frost normally sets in when the radiant temperature causes the plants to drop below the dew point of the surrounding air. If dew on plants freezes, it may cause damage to the plant tissue. One way through which plants may be protected from frost is by the use of heat exchangers in a double plastic-covered greenhouse. The heat exchanger becomes useful in heating the soil in the greenhouse. Infrared radiation, hot water, or hot air can be used for heating a double-covered greenhouse.
Where the use of the other methods is not possible, kerosene heaters may be used; however great caution must be taken to draw in fresh air into the heater for complete burning to avoid a build-up of excess moisture inside the greenhouse air. The largest heater possible should be used for efficient burning of the kerosene. The high operating cost with them, fire hazards incurred, and heavy labor often demanded must not be forgotten. Cleaning of hoses and burners after winter use is also necessary. Preference may be given to automatic small greenhouse heater units that do not require large amounts of fuel.
Other frost protection methods for greenhouses involve the use of frost blankets, sprinkling water on plants, the installation of fans, and the use of heat sources. There should also be checks on temperature fluctuations to enable the safeguarding of plants against frost.
Choosing Cold Weather Greenhouse Plants
Some of the popular cold-weather or winter vegetables suitable for greenhouse growing include kale, Swiss chard, spinach, lettuce, mustard, collard greens, and microgreens. These vegetables do very well during the winter seasons and give one a continuous supply for harvesting if multiple planting is done.
Light requirements can be another basis for the selection of which cold-hardy herbs and flowers are to go in the winter greenhouse. A few selections are rosemary, parsley, thyme herbs, and flowers like pansies, violets, and primrose. They add color and freshness to the winter greenhouse environment and grow well in those conditions.
Conclusion
Many enthusiastic gardeners have witnessed how very heavy snow and harsh weather can be devastating to plants in a greenhouse. As you begin working on your winter greenhouse projects in heavy snow states, be sure to continue reading about our recommended methods and information that can allow you to continually improve greenhouse gardening. Possibly the most important point taken from this article is the need to be proactive when it comes to winterizing your greenhouse.
