My first greenhouse was a disaster. My aunt was giving away her old greenhouse, most of the glass was broken, and the wood structure was old, brittle and fragile. It wasn’t long before we made another trip with our “new” greenhouse. And that was straight to the dump.
At that time in the mid-1980’s I had no idea, literally no idea, how to improve growing conditions in my Airdrie, Alberta garden short of building a greenhouse. I just had to have a greenhouse. I thought it would make everything better.
Gradually I began the long slow process of learning to grow better with modest shelters before I eventually I made my way back to full-on greenhouse ownership.
My newest greenhouse in Calgary, Alberta, is a beauty and a delight to grow in. Right now I am harvesting spinach and moving plants from my basement grow lights to their summer home in my greenhouse. Donna Balzer photo
It is March 2, 2025 and in my unheated greenhouse my open pollinated Bloomsdale spinach is officially ready to pick. With all the tariff troubles my country is facing, it is wonderful to grow my own food even in a cold, zone 3 climate. Spinach, bright green and shiny, is my favourite salad this time of year. Donna Balzer photo.
It is still months away from frost-free gardening weather outside in my zone 3-4 garden in Calgary, Alberta, Canada.
But this isn’t the story about how I failed with my first greenhouse as much as it is about growing a garden using all the help Northern gardeners can get: cold frames, row covers, heat cables, raised beds, basement grow lights and yes, the luxury of luxuries – a home greenhouse. There are so many things a gardener can do short of moving an ancient and fragile old wooden greenhouse across a city and into a new subdivision where the wind blows so hard a tree I plant two years earlier blows over in a sudden squall.
Do you really need a greenhouse? I do. But meanwhile, here are some tips to improve your garden before you jump into the deep end and order a greenhouse. A shopping list of steps that you can grow into.
SHELTER FROM THE WIND
Seriously, one of the biggest greenhouse benefits is shelter from the wind. My grandparents knew this when they put up shelter belts of trees and shrubs on their farm in Saskatchewan. They needed shelter. Shelterbelts saved the soil and saved the sanity of the farm family. This Sunday, when we had gale winds of over 100 km an hour all around Calgary, sitting in my greenhouse was a blessing. Quiet and calm and cozy. The plants appreciate the calm too and any wind-breaking structure can give plants a better place to grow,
An example of a wind-break in modern terms is a cold frame or hoop house. It is a simple, usually poly-covered, unheated structure, that breaks the wind and captures warmth from the sun, trapping it in the soil. This means crops like tomatoes grow better and produce faster than if they were growing in a field. If you can’t afford a greenhouse maybe you can put up a wind breaking cold frame or hoop house or poly tunnel.
This veggie hoop house is at Chinook Valley Ranch in Southern Alberta (2004.) Warmer soil and shelter from the wind helps plants grow quicker and stay upright more often than they would outside in the wind. Donna Balzer photo.
Even though I had a big greenhouse in my last garden in a much milder climate (zone 7-8 Qualicum Beach, British Columbia), I still added extra temporary shelter from a mini hoop house or tunnel I built simply with Grownet stretched over #9 wire, pushed into the spring soil and lined with bricks to keep it in place. As an easily installed cold frame and wind-break, Grownet allows spring rains to enter the soil and helps hardy plants establish better because the wind speed is slower inside the tunnel even while it breathes.Covers also offer 18% shade from direct sun. Tunnels are easily removed when plants reach the top of the fabric. NEW SUPPLIER IN CANADA NOW FOR HAIL DEFENSE NETTING Donna Balzer photo.
SHELTER FROM DIRECT SUN
Most cold frames and tunnels do double duty. They shade young fragile plants from the wind and also shelter early crops from the power of the direct sun. Coming out from under the grow lights or greenhouse, small plants need extra care. The sun is just too powerful and, like the wind, it can harm fragile young plants.
I have used grownet (see image above) but it was a hassle having it sent to Canada from Australia and now the supplier’s website is no longer valid. A better solution looks like an Airdrie Company with a list of nettings options. Other materials that protect from the wind and sun are row covers made from a spun-bound polyester fabric. They are simply laid loosely on top of seed sor transplants as soon as the crops are planted. There are various weights and some are more frost tolerant than others. Check out various sources online but the main type I use is the Agribon19 available from several sources including Vesey’s in Canada.
Seedlings, like these basil plants, need to grow in a mild climate out of the direct wind and sun. Donna Balzer photo
To grow my best spinach in my unheated greenhouse this winter I covered the young seedlings with row covers inside my greenhouse. Most gardeners will simply use Agribon outdoors but this comes a bit later in the season.
On January 7th this year, my tiny spinach transplants were thriving inside my unheated greenhouse because I covered them with floating row covers and laid heating cables down the planter’s length. Donna Balzer photo.
SHELTER FROM THE COLD NIGHTS
A cold frame or row cover may provide 2-5 degrees of frost protection but if you want the most from covers you will add layers of these beneficial materials. Inside a large cold frame, a floating row cover topper gives extra cold protection. I used Agribon on top of my greenhouse crops, like spinach, because this protects them during unusually brutal weather conditions when you don’t want to heat your greenhouse. Below, a hoop house is prepped and ready for fabric layers to be laid over the inserted wires.
Inside this hoop house, small wire hops are set in the ground so that row cover can be placed over them to increase warmth over crops. Donna Balzer photo
Outdoors, row covers are used to extend the season, shade the crops or protect from pests instead of a greenhouse. There are many different products for many different uses.
Floating row covers are not always supported by wire because they are so light they “float” over crops. In this photo there are also fine nets used to protect crops that do not need extra heat, only protection from pests. Donna Balzer photo
Floating row cover is fantastic for producing early crops of hardy plants like lettuce early in spring. Donna Balzer photo
Old blankets are definitely not floating covers. These blankets are heavy and ineffective at keeping in heat during an early fall freeze. Donna Balzer photo
SHELTER FROM HAIL
A greenhouse is a great protection from wind and cold but it is also protection from Hail. Luckily there are fabrics available that are sold now for hail protection because if you are in a hail zone you know it. These fabrics can be stretched over a frame or hoop house or tunnel and in turn, when it hails, the hail will bounce off the fabric surface. The Hail Products look a lot like the grownet (shown above and below) that I used to buy from Australia.
When I first got a new product called Grownet I used it over small diameter irrigation pipe and used clamps to keep it in place and rocks on the edge to stop it from blowing away. It worked for a bit of frost protection, sun screen, wind shelter and hail and it doesn’t overheat in the summer. Some row covers like Agribon50 may be too warm for crops in the summer, so be careful what you use for protection.
ADDING EXTRA LIGHT INDOORS
My commercial greenhouse friend was happily surprised at my plants, grown under lights in my basement. My new lights from Veseys cost more than the average cold frame…. but since I already heat my home all winter, the only extra cost is the electricity to run the lights from early February until it is time to put plants in my greenhouse.
Started early February, my micro-dwarf tomatoes were big enough under grow lights to transplant into bigger pots by mid-February. Donna Balzer photo
And of course the answer to “when” I put plants in my greenhouse is simple: It depends. My leek transplants were started under lights on Feb 1 and a month later they were moved to my greenhouse when I started using my little fan and heater combo. This system is just meant to keep the frost off the plants. It is not warm enough for tomatoes. My other cold tolerant plants like herbs except Basil, onions, kale, lettuce and peas will be added to the greenhouse as the weather warms and then in late April, or early May I will add the hot crops like tomatoes, peppers and even my lemon trees.
My Meyer lemon tree produces it first lemons in February. The tree spends the winter in our minimally heated garage because it tolerates dim light and cool temperatures down to 10 degrees C or lower and it is already blooming now so will make even more blooms and fruit once I move it into the greenhouse in May. Donna Balzer photo
Yes, I have a greenhouse, but to save money on gas and electricity I do my winter growing indoors under grow lights. So that is your first step. Get good grow lights. As soon as you can afford them. And before you buy your greenhouse. Chances are you are already heating the house you are living in so only the electricity charges need to be added to the cost of early plants raised under lights indoors.
Transplanted into a blend of promix and worm castings, this small tomato plant is already budding into bloom on March 10th this year. I plan to have my first indoor crop of tomatoes from these early starts by May, about the time I transplant my other later tomatoes into the greenhouse. Donna Balzer photo.
AND SO – DO YOU REALLY NEED A GREENHOUSE?
I am sitting out in my greenhouse in the sun in February. Only my spinach is growing in there at this time but I am reading a novel in the sun and I am so content. I have the feeling so many others get when sitting in front of their wood burning fireplaces or under an umbrella in Mexico. But with my greenhouse I not have to leave home or my little dog Corle. So, for me, the answer is yes. I do really need a greenhouse.
Corle follows me out to the greenhouse when she is not reclining on the couch. Donna Balzer photo
I can do a lot of things outside in my garden and under my lights to raise better food. But the greenhouse is so much more than the garden. It is a gathering place for friends and family, a quiet place to get out of the house without leaving home, and a hobby house when I want to transplant seedlings to my heart’s content. My greenhouse is my dream house.
I might have been able to make the old, feeble wooden greenhouse work back in 1985 if only I had a few more hands-on skills. But a wooden greenhouse shrinks and expands. And without vents or any of the modern additions like hail-proof polycarbonate or double doors to let the space cool on a warm afternoon it just isn’t the place I want to spend my time. So I am happy I indulged in a brand new greenhouse when we bought our new old house in Calgary.
My first greenhouse was a disaster. But now, thanks to the expertise at BC Greenhouse Builders I am happy to say I love my greenhouse and I do not take it for granted. Not even for a minute. It is perfect in every way.
I am not alone in loving my greenhouse. The grandkids love every moment in the cozy comfort of the space and are now asking their mom if they can have a greenhouse too! Donna Balzer photo
The greenhouse is a special place to play for a gardener like me. Never mistake it for a tool or another type of gadget because it is so much more.
Want to know more about Growing Under Cover? Steven Biggs and I offer online classes and the next one is this week, March 13, 2025.
I FORGOT TO MENTION THE HEAT CABLES
Designed for keeping snowy icy roofs free from dangerous ice all winter, heat cables take very little energy. But they do pack a punch with heat when they are placed over the soil and beneath a floating row cover inside my greenhouse. My spinach would be a month away from being ready to eat if I didn’t have the heating cables.
Yay! One more way to grow food faster that I didn’t know about before I owned my greenhouse. And if you are wondering how long I have had greenhouses to grow food? My grand-daughter, age 3, is shown picking lettuce on the feature image for this blog post in my first BC Greenhouse Builders greenhouse. And she turns 21 this garden season!
Growing your own greens seems impossible without a greenhouse but it isn’t. A greenhouse just makes growing cosier.
THE END – or is it?
My first greenhouse was a disaster. My aunt was giving away her old greenhouse, most of the glass was broken, and the wood structure was old, brittle and fragile. My new greenhouse is amazing with long-lasting aluminum framing and unbreakable polycarbonate siding and roofing. Do you really need a greenhouse? I’m not sure, but I certainly do.
