Sounds ridiculous doesn’t it, but this summer I was able to witness the power of heat reflection from energy efficient windows killing a brand new landscape. Energy efficient windows are called Low E windows and are very common in replacement windows, new homes and commercial properties. Most people install these windows to save energy and protect their homes from the heat and cold and they do a great job. However, you should know the reflectance from these windows can be so intense that just a few seconds in the amplified sunshine can burn you and your plants. The heat is even more intensified when there is a drop in barometric pressure, the glass will bend slightly to cause a magnifying glass effect. This will destroy anything in its path and it can happen any time of year. This heat effect has been known to start fires and melt the neighbors siding, so your plants don’t have a chance. Mulch can be kindling and will spread the flames quickly across your landscaping. South and west facing windows seem to be the worst and can damage things up to 20 feet away. There are many ongoing studies on the heat effects of Low E windows, so I am sure you will be hearing more in the future. But, we need to save our landscaping now! Here are a few tips to help keep your house and your plants safe:
Screens covering the whole window on the outside will help deflect some of the heat
Tinted window film that reduces glare
Trees planted to block the sun from hitting the window
Use stone with no plantings near the heat area if none of these are possible.
New Installation of sedum trays on a patio under large bay window.
2 Days after install looked like roundup had been applied
1 Week almost complete death of sedums in the heat reflectance area