Do your house plants a favor this winter, remove any window screens in those windows. The average window screen blocks between 40-70% of light. Makes a big difference. Gene

Never thought about that but makes sense. I'll put that at the top of my to-do list.

Excellent though!! Thank you!,

Great share! Thank you.

Likewise with sheers that many folks mistakenly think block out only direct sunlight.

This is an interesting topic. The window screen we have here blocks about 25% of the light, brand new out of the package. I use a double layer of this material as 50% shade cloth for a growing area outside. To get those numbers I use a light meter, which I would recommend if anyone is curious about the exposure in different situations. They're not expensive and I was surprised by what I learned.

More than anything else in my experience, simply washing the window improves light transmission tremendously. Presumably you could also clean the screen. Dust and dirt tends to accumulate in the space between the window and the screen, more than anywhere else. One of our kitchen windows here is half screened (perfect control), and has never been cleaned outside, and that screen blocks 40% of the light.

I suspect the difference between 25-40% (my figure) and 40-70% (Gene's figure) may have to do with the material the screen is made from, or perhaps simply it represents the varying accumulation of dust in all the nooks and crannies over time.

Living down here in Southern Texas we have solar screens on our windows to help regulate cooling costs in the Summer months. I have 2 windows that I do not have screens on for this very reason. Our solar screens block around 80% of the light/UV and effectively block around 75% of the Sun's warmth from entering the room. They work amazingly well, however, if you put a plant in the window and expect it to grow, you will be sadly disappointed.

Great information, all.

Yes, to get my figure using a light meter I measured screens in about 12+ homes in my area. Now that I think about it, I doubt windows and screens are the same here as they are in the south or southwest. It is easy for me to talk about removing screens. If I need some fresh air in January, letting bugs in is not an issue. Another thing that is probably not the same elsewhere. Gene

gasrocks said:Yes, to get my figure using a light meter I measured screens in about 12+ homes in my area. Now that I think about it, I doubt windows and screens are the same here as they are in the south or southwest. It is easy for me to talk about removing screens. If I need some fresh air in January, letting bugs in is not an issue. Another thing that is probably not the same elsewhere. Gene

Yes, we have skeeters in our mild winters.

I have had a Money plant in front of my kitchen window forever. But since putting the solar screen on that south facing window it has slowly been in decline. I have it outside now.I hope it is not too late for it. It never occurred to me the screen would hurt it so much!

Hopefully it perks back up, Cheryl! Be sure to acclimate it back to the higher light levels.

I will @JamesAcclaims. It is in the shade for now.

Regarding the money tree, I tried so many spots in the house to get the right one. The best spot is the brightest spot- with sun coming through the window onto the leaves for several hours a day. I'm not sure who said money trees are easy, because they aren't.

Back to topic, we have half screens on our double hung windows. We started moving the screens to the top half of the window this summer, now leaving the top portion open for fresh air, instead of the bottom. We originally did it to improve air flow because I had so many plants in front of the window it was a chore to open the windows.

But the plants have since been growing like crazy since the screens have been on the top half of the window. Honestly, I had not thought about how and why the plant growth had improved, until Gene made this post.

At one time I had a job manufacturing security screens that would keep out intruders. Now I am looking at screens in a whole new way, thank you. This is a very helpful thread. Maybe some of you could collaborate to write a short article than could be published here on NGA to help others know about how the screens limit the amount of light available to plants.

And suddenly I have more real estate with pretty decent sun, all winter. It will make the plants so much more active and interesting this year!!