What Can I Put on My Glass Conservatory Roof?

In the United States we call them greenhouses and in Europe they're known as conservatories, but whatever you call them, these glass plant houses are useful structures for home gardeners. Glass is the clearest of all greenhouse coverings, but that transparency allows the full brunt of summer sunshine inside the conservatory. Many gardeners rely on temporary coverings to moderate summer sunshine and protect the plants.

About Greenhouses and Conservatories

Glass-covered conservatories are permanent structures and require careful planning and construction, but once finished are the most weather-proof greenhouses available for home use. Most modern conservatories have aluminum frames and tempered glass, although older ones were built with wooden frames. Some conservatories include built-in shading systems.

Greenhouse Paint

One of the least expensive methods of creating temporary shade for a conservatory is to paint specially formulated whitewash onto the glass. Several different types of greenhouse whitewash are available; most wash off naturally by the end of the summer or are removed with a soft brush. Some products are formulated to be opaque on sunny days but translucent on cloudy or rainy days. Greenhouse paint is available from greenhouse supply stores or through your local hardware store.

Shade Cloth

Shade cloth is a semi-transparent, woven material used to cover the roof and windows to reduce the amount of sunlight entering the greenhouse. Shade cloth is available from greenhouse supply houses and most hardware stores. Attached with clips or staples on either the inside or the outside of the structure, shade cloth is installed in early summer and removed in the fall, and lasts for several years. Muslin is a cheap alternative but rarely lasts more than one season.

Blinds

Fabric or plastic roller blinds can be installed on either the inside or outside of the conservatory. Raise and lower the blinds as needed by means of pulley cords. Outside blinds don't interfere with using the conservatory rafters to hang plant baskets, a problem with many shade devices attached to the inside of the roof structure. Some greenhouse manufacturers also offer slatted blinds, similar to household Venetian blinds, that ride on a track attached to the conservatory frame.

Silver Fleece Vine

James Underwood Crockett, the original host of the long-running PBS show "The Victory Garden," liked to grow silver fleece vine (Polygonum aubertii) over the greenhouse where the show was filmed. This fast-growing perennial vine climbs by twining, so it needs string or another small-diameter support to climb. Since it's lightweight and doesn't have adhesive disks like ivy or Virginia creeper, there's no damage to the greenhouse structure. The white-flowered vine is cut back to ground level each fall after a hard frost.

References

• Michigan State University; Greenhouse Shading Options; Erik Runkle; March 2008
• Clemson Cooperative Extension; Hobby Greenhouses; Nancy Doubrava, et al.; June 1999
• University of Illinois Extension: Silver Fleece Vine
• "Time-Life Encyclopedia of Gardening: Greenhouse Gardening"; James Underwood Crockett; 1977
• "Crockett's Victory Garden"; James Underwood Crockett; 1977