Unless a gardener lives in a tropical climate where plants grow lush and strong year-round, winter can be a challenging season. Frozen ground and limited sunlight makes keeping plants alive hard enough in many circumstances, and encouraging new growth is usually out of the question. A winter greenhouse is all about defying these norms. Winter greenhouses are gardens that are enclosed, heated, and lit such that plants, particularly vegetables, can be cultivated and harvested in the winter months. The greenhouses can be small or large, homemade or commercially assembled.
Gardening in greenhouses is generally a bit different than traditional outdoor gardening. In a greenhouse, conditions can be manipulated to optimize the growth of certain plants. Temperature, humidity, and light exposure can all be coordinated to mimic the natural conditions of a specific season or growing region. A winter greenhouse is usually designed to create summer-like conditions, to enable the growth of traditional summer crops like lettuce, herbs, carrots, and even squash.
Winter greenhouses have been a popular means of year-round gardening for quite some time, but the practice has gained traction in recent years with the rise of the organic, locally-grown food movement. In many modern cities, fresh produce is perpetually available in grocery stores, even if it is out of season. This is owing largely to international shipping arrangements and the importation of fruit from places where it is either in season or commercially greenhouse-grown. The local food movement advocates avoiding foods that are not grown in one’s own community. Without a winter greenhouse, however, the winter months can challenge even the most determined local consumer.
A winter greenhouse is almost always an outdoor greenhouse, and can be either custom or commercially built. Some people build their own winter greenhouses, either on porches or in backyards. Personal greenhouses allow for highly customized winter gardening. A gardener can grow only what he or she likes in the specific quantity desired, using only minimal resources. Construction is also more flexible when it comes to smaller spaces.
The largest winter greenhouses, like traditional greenhouses, are complete structures. They are typically free-standing buildings, generally made of tempered glass, and often have independent electricity and water sources. For novices, these construction details can be daunting. Many do-it-yourself winter greenhouses are built in sheds or smaller pre-existing structures, and are powered by free-standing lighting and heating units.
This is not to say that large winter greenhouses are uncommon. Some communities together sponsor winter greenhouses, where individual gardeners can rent or borrow plots to grow their own winter crops. Still other large greenhouses are operated commercially, growing produce that will be sold to the community in something like a wintertime alternative to a farmer’s market. With a winter greenhouse, the benefits of 12-month gardening can become a reality for gardeners and consumers alike.