Energy Efficient Windows Effect On Your Landscaping

window 300x300 Energy Efficient Windows Effect On Your Landscaping

Energy Efficient windows may be a great savings inside the home, but their effect on your landscaping can cause you just the opposite situation, as magnified rays are reflected from your windows directly onto vulnerable leaf tissue.

For several years I have observed the damage in turf grass and garden plants caused by the radiant heating that comes off of new energy efficient windows. In areas exposed to full summer sun for more than 8 hours a day, I have measured temperatures up to and exceeding 160 degrees beamed directly onto plant material. Plants that normally seem healthy fall through spring will begin to show leaf scorch, and die back to the ground. Areas around your house that were lush and green prior to your window installation now look dry and damaged through the hottest summer weather.

How To Discover If Damage Is Due To Energy Efficient Windows:

  1. Monitor your plant life from summer to fall, and spring to summer. Look for drastic changes in leaf production related to warm weather months that are not due to visible pests, and that change once again in the milder months.  Does the problem seem to self correct in cooler months?  Do your shrubs lose leaves at the top, and continue to produce leaves and shoots from the roots?
  2. Check to angle of light on your plants. Physically move into the effected planting beds, or turf area.  Place yourself, or your hand over the plant, and see if you can cast a shadow over the plant.  Energy Efficient Windows have built in layers of glass in them and cast light in several directions. An area experiencing burn-out due to these windows will not show a true shadow, and while a plant you are leaning over will remain totally lit, a very light shadow will appear somewhere far from the actual plant. Any shadow that appears under these conditions will have light refraction shining through it, and have holes of light in it, appearing far too light to be an actual shadow.
  3. When looking for a shadow and excessive light over your plants with your hand or body, see if the area you are standing in feels dramatically hotter than the air around you.  Regardless of how hot the air may be, an area in full sun with light reflecting on it will be significantly hotter.  Windows will reflect heat like a magnifying glass onto you and your plants, and you will be able to discern the difference between this heat, and that of prior windows.

How To Minimize The Effect On Your Landscaping:

  1. Water your plants once per day or every other day to help keep the plant or turf area alive through the hottest days of summer.  Complete all watering on lawn areas after 6PM in the evening, or in the early morning, to ensure that water droplets have evaporated before the reflective heat reaches the area. In planting beds  provide ground level water, with drip hoses, or direct spray below the leaf line to hydrate the plants. Water droplets on leaves during peak sun hours magnify the light even more onto the leaf tissue, and guarantee large amounts of damage.
  2. Change the type of plants you plant in effected areas.  Keep bulbs and flowers in effected areas during the spring and fall months, but leave the summer flowers out of these areas. Concentrate on planting bushes in these areas that can take more heat than the delicate leaves and flowers of perennials, and annuals.
  3. Adjust the shape of your garden beds if the damage can’t be altered by water alone. Low windows that begin two to three feet off the ground give your plants no break from the sunlight from the moment the sun rises, and begin to radiate heat on your plants early on in the day.  Spend some time on a Saturday morning with string or measuring tape, and set them in the lawn or garden to denote and give yourself a visual marker of where the reflective light moves under your windows.  Once you have a good idea of which areas are the worst effected by the excessive heat move the boundary lines and shapes of your garden beds to protect your plants and transplant the landscaping in the greatest danger of sun scorch.

I have found that the worst and lasting damage appears around apartment buildings, where stacks of windows on the side of a building concentrate their burning light on a limited area.  Large bay windows can also be culprits when you see this type of burn damage. 

Creativity can be a great asset when you discover this problem in your yard. Tackle the tips in this list slowly, and avoid transplanting your damaged plants in the midst of the summer months, to prevent adding transplant stress to your plants current issues. Use the early fall months to rearrange and shuffle your plants around.  If you aren’t sure what shape bed to adjust your landscaping to fit, place a garden hose in several shapes in your garden, or on your bushes, and watch how the light plays around it for a few days.  Once you find a shape you like  that will protect your plants from the worst of the radiant heat, you are ready to re-design your bed! For turf areas that repeatedly die back, build a re-seeding program into your fall yard work plans to combat empty spots in your turf, and ensure a constant crop of grass.


Photo Courtesy of: kyz

About Amy


  1. Now THAT is an informative article. I cannot think of a single home owner who would think about the reflections of new energy efficient windows on their garden. I certainly didn’t think about it!

    I am also thinking about purchasing an apartment complex. This is great to know! Now I’ll keep my eye on the windows and the plants more consciously.

    Good stuff.

    -Kellen Kautzman

  2. Amy says:

    Thank you Kellen, and good luck with your real estate ventures! Keep an eye on the window stacks on the apartment building, plan accordingly, and you’ll have great success.

  3. Barbara says:

    My neighbors replaced the windows on the 2nd story of their west facing home. 2 windows, each reflecting in different location of my yard. I live close to the beach, afternoon sun refection could easily start a fire if I put dry wood in its path. It destroys my landscaping and my patio furniture. With each death it seems to move on to the next as the seasons pass. I chase it with umbrellas and covers. My yard was my greatest zin place….not any more.

    When I called the Co. that installed them, I was willing to pay to fix the problem. They, “Millgard” said “we’ve never heard of this before and the only solution was for my neighbors to go back to plain glass and fade their hardwood floors again.

    Thank you for your site. I knew I couldn’t be the only one with this problem

  4. Jonathan says:

    I actually had this exact issue. I thought a fungus was rapidly spreading throughout my garden, I had so many dead leaves, and it would “spread” from one plant to the next. Turns out I had removed all my screens from my windows (makes the house look nicer) and the windows were burning my plants. I literally had a straight line of burnt leaves that would move an inch a day, as the sun setting angle moved slightly, so it was burning my plants 1 inch at a time in a linear fashion. Fortunately the plant is still healthy, and should re-grow in the spring. I just need to put my screens back on my windows before next summer!

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