Cold Climate Gardening - how we do it here in Wyoming
The idea of cold climate gardening should appeal to anyone who lives in a location with a short growing season. That's exactly what we have here in southeastern Wyoming. Our short growing season makes vegetable gardening a bit of a challenge. (Not to mention the hail we get throughout the spring and summer.)
With that in mind, it seems reasonable to want to stretch the vegetable gardening season at both ends, and make better use of the wonderful sunshine we have.
That's exactly what winter gardening can help you do, and this article provides some examples of how we do it.
With all our wind, we decided to build greenhouses. They are essential to keep the wind from drying out our vegetables during the regular growing season, and they are a key to our approach to cold climate gardening.
The Ground Rules
First of all, understand that our greenhouses are unheated, except for what the sun provides. I suppose that makes them solar greenhouses, but then aren't they all? Anyway, with an unheated greenhouse, you have to work with nature, instead of against it.
Second, since we live in growing zone 5, that means our low temperatures get to about minus 20. That's 51 degrees below the freezing temperature of water.
The look of -20 on the thermometer is a real attention getter if the furnace goes out. It's no less an attention getter if you're trying to keep vegetables outside from freezing, so that requires row covers or cold frames inside the greenhouse to capture additional heat from the sun during the day, and to capture ground source heat as well.
Third, our last frost can be as late as early June, and our first frost is typically late September, so our growing season is short. We have 3 and a half months of solid summer growing weather, and that's it.
So, with those three ideas in mind, let me tell you how we go about cold climate gardening to keep fresh vegetables on the plate during the winter.
Cold Climate Gardening in Late Summer
After selecting seed for our winter vegetables, we do a little planning as to where we're going to plant them. For an early start, we get the winter vegetables growing soon after we yank out the spring vegetables that are bolting or withering in the warm weather.
If we don't "hot swap" beds, then we simply set aside some portion of the growing beds for late summer and early fall plantings. Our goal is to work backwards from the end of October, the number of days the vegetable will require to mature.
A few plantings a couple weeks apart is nice because that gives us some sort of succession of harvest as well as a margin of error should our weather turn colder sooner than expected.
We plant and let the winter vegetables get up and running, and we harvest a few as a test for quality, and to supplement our produce variety with the summer vegetables that are coming on strong right about then.
As colder weather starts to set in, we put our cold climate gardening plan into action. We stop watering altogether, and lightly cover the winter vegetables with a row cover to promote continued growth and protect them from sharp drops in temperature.
We vent the row covers during exceptionally sunny days and during times when the weather is warmer than expected.
For exceptionally cold weather, we either place an additional clear covers over the winter vegetables during the day to trap in another layer of warmth, As an alternative, we place an opaque cloth cover over the vegetables at the end of daylight to help keep the warmth around the plants during the night.
All row covers provide a "greenhouse within a greenhouse" for the plants, and they respond well to this extra protection.
We remove any opaque cloth cover in the morning to help sunlight get back to the plants to warm them up.
Cold Climate Gardening in Spring
A similar approach can be used for cold climate gardening in the early part of the year to get things started ahead of the normal summer schedule.
We typically start our plants indoors or outdoors in a cold frame curtain type setup that includes seed trays and heat mats on a large and sturdy shelf in the greenhouse that is exposed to sun during the day. The seed trays are covered with a dome as well to trap in warmth and moisture.
With early June being our safe outdoor planting time, we target no more than 6 weeks earlier for our first plantings inside the greenhouses. Even at that, we sometimes need to cover our plants if the weather takes a sharp drop into the teens or single digits overnight.
Row covers are easily put in place just like we do for winter protection. We also loosely place bricks around the seedlings to capture warmth during the day and emit that warmth throughout the night.
Since not all of our planting beds are set up for row covers, we also use quart and gallon glass jars to provide a "greenhouse within a greenhouse" for the little transplants. When using this approach, we take the jars off during the bright sunlit portion of the day, and put them back on while there is still sufficient sunlight to allow it to raise the temperature inside the jar without overheating it.
Slow Maturing Plants
Some plants take a long time to mature, and this presents a problem. For example, Brussels sprouts don't do well in the heat, yet they can't be planted in the fall with any expectation of maturing before winter sets in.
To combat this fact of life in a cold climate gardening location, we plant Brussels sprouts, broccoli and other long maturing winter vegetables in the spring, and let them go dormant in the summer heat.
After the heat of summer has passed, the vegetables are kick-started by the onset of cooler weather, and they start growing and producing again. Still needing more time to mature, we cover them to the extent necessary to keep them in cool and comfortable temperatures instead of the deep freeze.
This approach allows us to harvest vegetables in the winter that we normally would never be able to harvest anytime during the year because of the short growing season.
It Works for Us Here in Wyoming
So, there you have it - our approach to cold climate gardening using unheated greenhouses, row covers and cold frames. It can be surprising how well it works. Remember, there isn't a magic formula for any of this. Much of it depends on your particular situation.
Therefore, success with cold climate gardening will depend to a great extent on your ability to translate our experience into your growing zone, availability of sunlight and typical winter weather conditions. It will also require a bit of experimentation to see what works best for you.
Push the envelope with your cold climate gardening, and see if you can't stretch out your vegetable growing season.
You don't necessarily have to build a greenhouse for vegetable gardening in the winter; you can use a garden tunnel, or simply place a clear cover over your cold frames. Be creative, and be persistent, but try to work with nature instead of against it.
Done with Cold Climate Gardening, take me back to Winter Gardening