When summer arrives in Rhode Island, I move everything out of my greenhouse in preparation for a cleaning blitz, including window cleaning. It’s easy to clean the outside of the windows year-round because no plants are in the way. But when the greenhouse is full, cleaning the inside of the windows is difficult because access to them is blocked by so much vegetation.
Although soap, water, and a regular window-cleaning squeegee does the trick on the greenhouse glass exterior (and can clean the inside), for the glass interior I use a special squeegee called a water blade. Its blade is made of medical-grade silicone and has a T-shaped edge. It is softer than a regular squeegee and is used for cars and yachts where it is crtical not to damage anything. A number of manufacturers make squeegees of this kind, but I’ve had very good results with those produced by Starbrite and Shurhold, both available on Amazon. A water blade can be either held in your hand or fastened with a special clamp to the end of an aluminum handle that’s extendable to 8 feet. Using the handle, virtually any part of the greenhouse glass can be reached without needing a ladder.
My first step in cleaning the inside of my greenhouse windows is to remove any algae from the glass and around the edges of the window frame. This can be done with plain soap and water using a large sponge. If the sponge alone isn’t adequate, I get the remainder off with a Shurhold boat cleaning scrubbing brush, available with either stiff or soft bristles.
With the algae gone, I next wipe down the glass with my water blade squeegee. Using soap and water alone as a cleaning agent may leave an occasional streak, so I often do a final wipe-down with paper towels and an ammonia-based commercial window cleaner. This gets the glass crystal clear and helps to keep it clear for a long period. In fact, the glass may be so clear that birds accidentally fly into it. Putting temporary decals on window panes can help avoid this problem. I also set my tallest plants around the exterior of my greenhouse to help keep birds away.
My last step in window maintenance is to touch up any paintwork that may have been damaged moving plants around, oil any hinges and latches, and vacuum the place out. In a clean, empty greenhouse, this is a relatively easy job, as is making sure that the heating, lighting, and irrigation systems are all working properly. With these tasks completed, I move the most heat-loving (tropicals) of my plants back into the greenhouse where temperatures can soar to 120 degrees if I don’t monitor it. The other, more temperate, plants will spend the summer on the outdoor patio enjoying the sea breezes.