There are many factors that go into what you can garden. Your Plant Hardiness Zone is a pertinent piece of information when deciding what to plant and when. In Canada, we have a wide range of garden zones with vast variation within provinces. The zones range from 0 to 9, with zero being the coldest and nine being the warmest average conditions.
Knowing your zone is a helpful guideline, but it is important to note that garden zones change over time. Our climate is continually changing, and with that, our zones do as well. There are also micro-climates within zones that may not be accounted for.
The zones do not take greenhouses into account. Therefore, having a greenhouse often means you can plant sooner than the dates suggested for given zones.
Importantly, a heated greenhouse will allow for different planting times than non-heated greenhouses, or outdoor gardening.
It is helpful to know your garden zone, but as you become more experienced in the garden, you will learn your specific needs and capabilities.
The Government of Canada created pages to determine your zone. You can determine your Plant Hardiness Zone either by looking at the map, or by searching your province and municipality. Simply visit the headings below, to either view the map or search your Province with the first letter of your area to determine your plant hardiness zone.
Germination (growing from a seed to a plant)
For a seed to germinate, the following are essential: water, oxygen, soil, and warmth (and often light or darkness). Of course, the specifics vary for each plant. Because there is no one size fits all for gardening, learning about the environment you have and what you would like to grow is very important.
An important stage in germination involves the activation of metabolism in the seed’s embryo cells, which requires heat. There is therefore a minimum temperature for germination to occur.
For most plants, the optimum temperatures range between 15-30°C (60 -86°F).
To start seeds in an unheated greenhouse, you will need to check the minimum temperature. If it is above 15°C, most seeds can be planted.
There are also a wide variety of plants that can be germinated below the temperatures listed above. For example, cabbage and parsley can be planted around 4°C, and onion and spinach have germination temperatures closer to 0°C.
As long as you know the minimum germination temperature of the seed you want to begin growing, you can determine whether the minimum temperature of your unheated greenhouse is suitable. If your greenhouse is not warm enough for the seeds you would like to germinate, you can add heating to your greenhouse.
A heated greenhouse will change what you can plant, and when, in your greenhouse. We have Heating Options available if you are interested in a heated greenhouse.
You might be starting to sense a theme by now that there isn’t quite a universal right answer when it comes to gardening, as there are many factors that go into each decision. This is also true of the location of your greenhouse. The ideal location for your greenhouse is all based on how you plan to use it.
If you intend to grow plants to maturity, or grow in fall and winter, maximizing sunlight is vital. The first choice of location would be south or southeast of your home or other structures that may obstruct light. A southern location will provide the most amount of light, but may require shading in the summer. The next best choice would be east of your home or structures, as it will capture more November to February sunlight than other positions. The least desirable position would be the north side of your home or structures, as it will provide the least amount of sunlight. A greenhouse location that provides full sun exposure in the summer, may be covered by shade in the winter.
While commercial growers tend to prefer a north/south facing greenhouse because it provides even light distribution, some research suggests that your latitude dictates the ideal direction. Regardless, it is suggested that the entrance faces away from prevailing winds to reduce heat loss from cold air entering your greenhouse when opening the greenhouse doors.
We hope you find this information helpful. As we continue to learn more about gardening, we will continue to share with you.