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Four Factors You Must Consider Before Buying a Greenhouse

Working in a greenhouse

As you know, greenhouse growing on a market garden is very lucrative but requires proper installation and some knowledge. Before you make such a big, lasting investment, allow us to give you a little more insight with four factors you must consider before buying a greenhouse

What kind of greenhouse installation do you have in mind?

When choosing your greenhouse, you should consider whether you will be installing the greenhouse yourself or paying for the installation. If you are installing a greenhouse then you will not be able to go wider than 35 feet as anything larger requires special equipment. Whether you’re considering buying a gutter-connected greenhouse or a simple 30 ft X 100 ft one, you will need to consider the initial investment and what your greenhouse needs are.

What cultures do you plan to grow in your greenhouse?

One factor you must consider before buying a greenhouse is what kind of production you are aiming to do on your farm. If you want to grow tomatoes, peppers, cucumbers and eggplants in your greenhouses during the summer and early season variety, you might want to consider having a couple of 30 to 35 feet greenhouses rather than a large connected greenhouse as all those crops have different climate needs. It’s also great to have more than one greenhouse as you can “flip” one from summer to winter crops in August without missing out on the end of the greenhouse season with your main summer crops.

Greenhouse size is one factor you must consider before buying a greenhouse. / Credit : Alex Chabot
Greenhouse size is one factor you must consider before buying a greenhouse. / Credit : Alex Chabot

What size do you want for your Greenhouse?

You need to be forward-thinking in your selection of greenhouse size and model. Whether you’ve been growing vegetables for 2 seasons or 10 seasons, you should expect that as you improve and make more money, you will want an upgraded greenhouse. By starting with a greenhouse that can evolve with you, you will not need to make the investment twice. First thing to consider is how long, tall, and wide you want it. Rather than buying a simplified greenhouse that cannot accommodate proper climate control systems, you might consider a “fancier” option so you can optimize your crops with the most appropriate climate. When it comes to greenhouse size, you want to have a good volume. Counter-intuitively, it is less expensive by square meter to heat larger air volumes than it is to heat smaller air volumes. Large air volumes facilitate heating and management of the greenhouse climate, because they have a better temperature stability. Not to mention the higher a greenhouse is, the more luminosity it will have which will increase plant growth, health, and hopefully, crop yields.

Insulation is one factor you must consider before buying a greenhouse. / Credit : Alex Chabot
Insulation is one factor you must consider before buying a greenhouse. / Credit : Alex Chabot

Don’t pay year after year – insulate your greenhouse

One factor you must consider before buying a greenhouse is isolation. Like any 4-season structure, greenhouse isolation is critical. Where we grow in Southern Quebec, we have greenhouse crops year-round even when there is ice, piles of snow and little light. If you have doubtful insulation, you will be paying for it in the long run, year after year. So you have to search for ways to insulate your greenhouse to a maximum. It is worth taking the time and investing in it. First, the choice of the material that covers the greenhouse matters. There are many options – glass ($$$), rigid plastic ($$) and polyethylene ($). With our climate, we decided to use double-layered polyethylene with airflow between both layers, which we think has the best ratio insulation/price. The downside is that it has less luminosity transmission than glass for example and you’ll need to replace it after 4 years.

Once that choice is made, install insulation panels 2 feet in the ground around the greenhouse. You can also insulate the north wall and seek for any air infiltrations (doors, tears, vents) for even better insulation of the greenhouse!

Want to learn more before making your decision regarding your greenhouse?

We have prepared a series of articles that will help you expand your knowledge on the topic of greenhouse installation so that this endeavor can be more enjoyable and less stressful.

Learn about other factors you must consider before buying a greenhouse :

If you need any more resources to help you with your greenhouse production or to learn about best practices for operating a profitable farm, we invite you to join the Market Gardener Masterclass. The Market Gardener Masterclass is a comprehensive online course that documents all the steps of successful market garden production. Our method has been developed based on over 20 years of experience in organic market gardening and is designed to allow you to deliver consistent results that will guarantee the success of your farm.