Backyard Greenhouse Gardening

This fall we decided to add a backyard greenhouse to cover our vegetable and herb garden beds. This post details how we chose our backyard greenhouse and how it’s been working so far. We also discuss what we’ve done to allow it to extend our growing season. You can expect more posts as the fall and winter season inch forward by reading our Gardening section.

Outsunny 12ft x 10ft Walk-in Greenhouse

Strong, lightweight and affordable. This greenhouse will extend your growing season!

The backyard and Our Gardens

Our yard has a wonderful southern exposure which means we get loads of sun throughout the day. We have two 8 ft x 4 ft garden beds in our backyard and we have been making good use of them.

With the change in habits through the COVID-19 pandemic, our family has been focusing a little more on the growing of vegetables and herbs. It all started as a seed and sprout project in March of this year, and then when summer began to fade away we felt we should try to extend the growing season.

Our Gardening Zone

Living in Southwestern Ontario means that we already have one of the best climates for gardening in Ontario. Based on hardiness maps online, we’re in Zone 6b with a low range of -20C to -17C. This may sound cold, but when compared to -38C in Marathon,one of our most northernly cities, we are downright spicy!

There’s a wonderful interactive map of Ontario which overlays the hardiness zones for you to understand your zone: https://www.plantmaps.com/interactive-ontario-plant-zone-hardiness-map.php

The Backyard Greenhouse

And so, we decided we should consider a backyard greenhouse. The principle is pretty simple: We need a way to increase the temperature of the garden beds and to protect the vegetables from the elements (which can get pretty harsh in our zone).

A simple and compact greenhouse structure was at the very top of our list. We’re in a rather urban setting with a simple backyard layout. We knew that building a greenhouse out of old windows would be more expensive than we’d like. A brand new glass greenhouse seems a bit extravagant, so we opted to find an affordable metal-framed greenhouse with a Polyethylene cover.

Our Backyard Greenhouse Selection

We chose a 10 ft long by 12 ft wide greenhouse from Outsunny for approximately $200.

Product image of the Outsunny 12 x 10 greenhouse
Outsunny 11.5’x10’x7’ Walk-in Greenhouse

This greenhouse had our fundamental requirements:

  • Affordable and under $300.
  • Metal frame
  • Durable UV resistant cover
  • Windows to help with airflow and to control the humidity level
  • Tall enough for me to walk in (I am 6 feet tall)

Backyard Greenhouse 2.0: Necessary improvements

The reality is that this is a functional greenhouse with everything you need to embark on this gardening voyage. But it is very cheaply built. The Amazon.ca reviews for this greenhouse are littered with buyers either raving positively or ranting negatively about the greenhouse.

Surprisingly, the cover and the ropes attached to the cover are incredibly well built. It took 120 km/h winds to damage one of our seams, but the locations where the ropes attach are still damage free (as are the original ropes!). Read about the repairs and upgrades we’ve applied to the greenhouse.

After having used this greenhouse for 6-weeks now, we enjoy using it but we’ve come to learn that you will want to improve the greenhouse with the following upgrades:

  1. Anchor the frame to the ground with metal stakes. We recommend IME Ground Rebar Stakes from Amazon.ca.
  2. Reinforce the corners of the cover, and the seams, with heavy duty tape like Gorilla tape. You can find Gorilla tape at Amazon.ca.
  3. Replace the stakes provided for the cover, and use heavy duty plastic stakes instead; like these stakes on Amazon.ca.
  4. Tape the windows shut if your greenhouse is not in a wind prone area. This will help keep a bit of the heat in (though the cover has no thermal retention), but mostly it will keep the bitterly cold wind from entering the greenhouse. If it is in a wind prone area, we recommending leaving the windows adjustable as you’ll want to allow some wind through the greenhouse on really windy days (or risk converting your greenhouse into a balloon)

Heating your Outsunny Backyard Greenhouse

We are keen to extend our growing season beyond September and October, but we’re also not interested in paying more than we need to grow our own vegetables. With this in mind we decided to run a few trials to see if a 1000W blowing heater can heat the greenhouse. The eventual question to answer: How much does it cost to heat the greenhouse with a heater?

The true method of knowledge is experiment.

William blake

We have done two tests so far, each test attempted to determine the following:

  1. How long will it take our heater to heat the greenhouse to 20C?
  2. How long will it take the greenhouse to cool back down to ambient temperature once it is shut off?

With these questions in mind, and our pen and paper at hand, we got to work and tested the greenhouse in two significantly different scenarios:

Scenario 1: Mid-day in Autumn, sunny and 15C

Scenario 2: Early morning in late Autumn, cloudy and 2C

The results from both were not very promising. It took 1 whole hour to move the thermometer dial 5C which meant we peaked at 20C in Scenario 1 and 7C in Scenario 2.

Running the heater for 1 hour will use up 1kWh, and at our current rate in London that would cost 20 cents ($0.20). If we need to run the heater for 5 hours in late fall or early winter, we’ll be spending $1.00 per day (the equivalent of $30 per month!).

Now, I love my fresh produce, but at $30 per month I would think twice about running the heater. The reality is that fresh herbs and kale can cost us $4 to $10 per week at the grocery store and I was hopeful we could save some cash by growing our own. I guess if I feel compelled to extend our season a bit longer I know the cost and will consider it then.

Happy growing! If you have any questions, feel free to leave a comment below.

5 Thoughts

  1. I think $30 a month is worth it. Grocery store produce just simply doesn’t have the taste and crispness of freshly picked produce. Love the write up and will refer to it when we are shopping for a greenhouse this spring!

    1. That is a valid point re: $30 being worth it for the control and quality of the produce. I’ll keep that in mind when I’m fretting over the cold and the cost. 😀

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