Tag Archives: winter and a greenhouse

Growing Over Winter in a Greenhouse

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There are quite a few ways to make a greenhouse more heat efficient to make it feasible to grow either through the winter or for a large part of it.

The first thing to determine is what crop(s) you wish to grow since a number of plant varieties would be considered cold weather crops. The heat requirement would be considerably less.

Since the majority of heat loss is through the roof, the most common method of making a greenhouse more heat efficient is by adding a layer of plastic to the outside. With the benefit of a small blower there is an air pocket created. The closer that this air pocket is to “dead air” the less heat transfer that there would be. 10 to 15 cm is considered the ideal gap. When there is more then 15cm there will start to be movement of air and greater heat transfer. It is impossible to have a perfectly uniform space because of the way the plastic goes over the ridge and is fastened around the edges.

It is important not to have any holes in the plastic. The resulting air loss with a hole would result in air movement and less heat efficiency.

It is often thought that a lower greenhouse is easier to heat since there is less surface area to lose heat. The reality is that the bigger air volume of a taller greenhouse is less likely to have the temperature fluctuate.

To make a structure more heat efficient, the north wall could be insulated. Care has to be exercised in insulating ends since it is important not to create extra shading. Insulation can be put flat on the ground around the structure as a way of slowing down the cold radiating into the structure.

Another trick that some people have used effectively to reduce heat requirements is to make small tunnels over the beds of vegetables. This works well for the night time. It is important to have this cover removed in the day time to maximize the value of the sunlight.

If your intention is to only use part of a larger structure through the winter, it is wise to hand a curtain for the length of the ridge and then only use the south facing side. This maximizes the benefit of the sun and minimizes the effect of the cold wind.

With a little creativity it is easy to get benefits from the greenhouse even in the winter.

Potential Ice Storm

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We are once again in a part of the season where freezing rain is a potential threat.

The freezing rain itself is not the threat, even if there is a lot, since at a certain point, if there is enough ice, it would become self supporting

Where the potential risk comes, if the temperature would fall and the ice would really freeze to the cover, snow would not be able to slide off the structure.

To prevent this from happening, take a few minutes to gently bump the cover to remove the ice.

The critical thing to remember when bumping the cover is to ALWAYS start at the top and work down. This way the lower ice will “protect” the cover when the higher ice is sliding down.

The sooner this process is done, the smaller the job will actually be.

But PLEASE do not go in a compromised structure, you are more important

Good luck!

Winter Storm and Your Structures

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Winter Storm & Your Structures

Many areas have been hit with freezing rain today and even though it has generally not been enough to warrant concern for the structures, it is a good time to recap some common things when dealing with ice on buildings.

It is important to note that the ice in itself is not an issue, even a very thick layer actually has enough strength to become self supporting. There are two potential problems though:

  • If the ice stays on the building, it usually has a rough enough texture that subsequent snow will not likely slide off. This scenario lead to major problems in previous winters when we had freezing rain, followed by a dump of snow and then we had rain. This can triple the weight on a building in very short order.
  • The other potential problem happens when you are attempting to remove the ice from the building. If the ice layer is not too significant you can gently bump the cover from the inside. ALWAYS start bumping the cover from the top. This way ice will slide over ice. Starting from the bottom creates a potential where the ice sliding down will fall back against the building and slash the cover. NEVER do all of one side and then the other. Work both sides simultaneously.

If there is the slightest doubt in your mind about the amount of weight on the building, bump the cover from the outside using something with a long handle.

If in doubt please don’t hesitate to ask.