Greenhouses come in a wide variety of different styles and types. Each is suited to a special need or want and degree of seriousness for greenhouse gardening. For the beginning greenhouse gardener there are smaller versions available that come in the form of portable greenhouses, a hobby greenhouse, or mini greenhouses. There is also the option to build your greenhouse from scratch with a foundation.

What exactly is a greenhouse? A greenhouse is a structure that creates a protected environment for plants to grow in, thus extending the productive lives of plants. Greenhouse gardening is a fun and functional way to garden all year around. You can pick tomatoes in the winter. Grow herbs and vegetables and start seedlings and cuttings. Some of the reasons to start a greenhouse:

Carrying over garden plants to be used as Greenhouse plants next season

Getting an early start for tender plants started from seed

Increasing the possibilities of a greater variety and continuous supply

Easier culture of small vegetables for winter use

To propagate and experiment with various plants as a hobby

Develop new varieties of plants

As with most projects, begin your greenhouse gardening with a plan. You want to consider the type of greenhouse you want (a cold house or a heated greenhouse) and the construction and type of foundation that is required. What type of equipment you will need, covering for your greenhouse, and what type of watering, humidity control, heating, and air circulation systems that will be best suited for your needs.

A cold house is the most uncomplicated of greenhouses. This type of greenhouse is not equipped with any artificial means of heat therefore the growing season is shortened when the outside temperature drops below freezing. Frost sensitive plants will not grow between late fall and the middle of spring unless you provide heat, which of course would not then be a cold house. A cold house does lengthen the growing season from that of gardening outdoors by trapping the heat from the sun throughout the day. In addition, it provides a cosy respite for you to enjoy your gardening away from the elements of wind and rain; it also protects plants from these same elements too.

Monitoring the temperature of your greenhouse is very important. If the temperature inside your greenhouse becomes too hot, your plants will wilt and die. On the other hand, lower temperatures can decrease the vigour and growth of your plants. Try to develop a daily schedule that maintains the best possible temperature. It does not take much to destroy all the work you put into your greenhouse; one hour of intense heat is all it takes. It is better to leave your greenhouse open, and have it a bit cool, than to have your plants die from the heat. For the first few days, check the temperature of your greenhouse several times. If you necessary, open the doors more and/or provide more vents to maintain desired temperature control. During the late afternoon or early evening, when the temperature has cooled, close up your greenhouse. This is a great time to water your plants and flats if they require it.

If you begin greenhouse gardening with a cold house, once you install a heater you will then be able to enjoy a true greenhouse. When you do this, you will transform your love of gardening into a year-round hobby. To grow greenhouse plants throughout the winter the minimum temperature is 45 degrees.

Unlike gardening outside where the rain waters the plants, it does not rain inside a greenhouse. Watering greenhouse plants is not simply taking a hose and saturating the soil. Within the soil, there are small open-air pores that roots depend on for providing them with nutritious gases. When you water your plants, these small pores fill up with water; which then causes suffocation for the plants roots. When the roots suffocate, the plants wither and it is very common for most gardeners when they see this to water the plants further thus causing further suffocation. Remember the watering needs inside a greenhouse are different because the environment is enclosed a majority of the time and a fair amount of moisture becomes trapped lessening the amount of water required. A good rule for watering is to check the soil and if it is dry then add water.