Glass greenhouses have been around since the 13th century, when the Italians designed the first of these structures to house exotic plants that merchants were bringing back from their travels. Since then, climate control and watering systems have been added, but glass greenhouses are still the gold standard in indoor growing. Everything from cold frames to large backyard greenhouses continue to be made with glass.
The benefits of choosing glass
There’s a reason glass remains the ideal material for greenhouse covering—it’s the clearest and most long-lasting material available. Clear greenhouse coverings are invaluable since the clearer the material, the more light that can pass through it. Unlike the various plastic coverings available, glass isn’t degraded by the ultraviolet rays that penetrate it each day, giving it a lifespan of 30 or more years.
Glass greenhouses also tend to harbor less disease since the material allows for a greater amount of air exchange and has no small pores in which to harbor pathogens. Glass greenhouses must be sturdier than their counterparts because the glass panels can be very heavy and require stronger structures to hold them in place. Most modern glass greenhouses use tempered glass or safety glass to help prevent breakage, increasing the durability of these buildings.
Backyard glass greenhouses are the Cadillacs of the greenhouse world and come in a variety of shapes and sizes, but are most often designed with traditional aesthetics in mind. Basic glass and aluminum structures as small as 79 square feet fit neatly into small yards, but if you’ve got lots of room and plan to use your greenhouse for years to come, deluxe packages including built-in misting systems are available in sizes up to 150 square feet.
Glass isn’t for everybody
Glass greenhouses are magnificent structures, but they’re not for every gardener. Glass structures have a high upfront cost due to the cost of glass, but can also be more expensive to maintain since they tend to lose heat more rapidly than other structures. Although glass is beautiful and timeless, it’s easily chipped by lawn equipment, broken by flying objects or busted by the pressure exerted during high snow accumulations.
If you’re not sure that your greenhouse is in the right spot or you intend to move it sooner rather than later, glass probably isn’t for you. Moving any greenhouse can be an ordeal, but a glass greenhouse is at increased risk of damage when you’re taking it apart and putting it back up—if you need a mobile greenhouse, plastic sheeting or panels are a much better option.
DIY greenhouses from old windows
Many DIYers are busily repurposing old single-paned glass windows into greenhouse. These old windows are still relatively abundant as homeowners update their homes with thermopane windows and can often be obtained for little to nothing. With some basic carpentry skills and a lot of sweat, you can build your own basic glass greenhouse with only a small monetary investment.
A word of caution: reusing windows for a new greenhouse requires a great deal of planning to design a structure that doesn’t look like it was cobbled together without thought. You must carefully choose the windows and doors for your structure and place it in the right landscape, or your DIY window greenhouse will look out of place—especially in formal or modern gardens.
Deciding between glass or plastic? Read Glass greenhouse vs. plastic greenhouse—pros and cons>>