Sunday, March 22, 2009
Extending The Growing Season
I was asked to elaborate on the construction of our row covers, and having considered doing a post on this subject in the past I was finally encouraged to do so. Season extending row covers allow us access to fresh salad greens at least until early January and often all year depending upon the weather. Regardless of the amount of snow received, if diligent in keeping the row covers free from snow, I am also provided with a place to plant greens, onions, brassicas and other cold hardy crops in the very early spring.
We also have a few cold frames and will be constructing more in the future and although they do have some advantages over the covered rows they cannot cover the amount of space needed and are also not as versatile especially in the sense that they cannot be easily removed when no longer needed.
It has been my experience that many winter greens, especially less mature (smaller) ones, can survive numerous freeze and thaw cycles. The trick is to provide them with adequate protection from the elements as the, wind, rain, and snow will take their toll on the crops long before cold temperatures will.
The design I chose for my row covers is simple yet effective, easily put up and just as easily dismantled and stored away for the season. Our garden rows are approximately 4' wide and anywhere from 10-60' long. I use 1" poly irrigation pipe for the tunnel frames and 4 mil, 10' wide plastic for the covers.
The pipe is cut with a hacksaw into 8' 4" lengths, to allow for taller growing greens such as Swiss chard and certain brassicas.
This fits nicely over my 4' wide rows as well. The hoops are held at ground level with 12" wood stakes that are cut from the many maple saplings that grow on our property.
The stakes are pounded at an slight angle about 6" into the ground and the poly pipe fits snugly over them.
Normally the hoops are placed 3' apart all down the row. Going forward I will be placing the hoops every 2' as we have had record snowfall the last couple years and more support is needed. At 3' apart the hoops will easily hold up to 2' of dry snow or a little over 1' of heavy wet snow before they are compromised.
A length of rope is staked to the ground at each end of the row as well as being securely looped around each individual pipe in order to prevent them from sliding back and forth.
A 5-6' long pole with a natural V shaped notch or one that I have cut is then placed at the end of each row to further stabilize the entire structure.
To further strengthen the pipes a piece of rope or twine can be attached to both sides of each hoop in order to allow it to handle more downward pressure.
Neither the ropes or end poles are necessary if snow is not an issue. I use 10' wide clear plastic sheeting as that allows for an extra 1' on each side of the row that can be held down with brick, rocks, or wood. In the winter I just use the snow to my advantage as the other weights often become frozen to the plastic.
The plastic is cut lengthwise so that it overhangs each end of the row enough to be held down with another weight.
There are a few issues with this type of season extension. The snow can accumulate faster then you can remove it and the structure may collapse under the strain. While shoveling the snow off it is easy to tear the plastic. I find that a piece of duct tape attached to each side will fix any rip and often wait until summer to repair the tears as I am able to dry the plastic in the sun and this really helps the duct tape to bind with the sheeting. Some of my tape jobs have lasted over 3 years now.
One of the biggest problems is the plastic freezing to the ground, my only solution to this is to patiently wait until a warm day allows for the removal of frozen ice and snow. Lastly, the plastic sheeting can be blown off when the wind catches it if not held down in enough places.
Although row covers as season extenders take some effort, the choice has been made to use them as it affords us the ability to procure fresh produce from the garden much longer then otherwise possible and also fits into an ongoing goal to provide for ourselves. As our quest for food self-reliance progresses, we find ourselves increasingly reluctant to consume food from sources other than our own garden. The availability as well as the quality of the produce offered in the supermarkets is most disturbing and I would just as soon not have to wonder what is in, on, or being done to our food. Below are a couple other posts I've written regarding cold weather gardening.
There Is Nothing Like Salad Fresh Out Of The Garden In January