How to identify lawn problems

One of the problems with lawn care is you don't get to see the problem until it's too late. It would help if you could detect if there was a problem with your lawn sooner so you could do something about it.
To accomplish this you need to take off your rose colored glasses and have a good hard look at your lawn... with purple colored glasses!

I saw a web page talking about stress detection glasses that are used to see stress in plants up to 10 days sooner. They were very expensive. If you're a turf manager at a golf course or other sports field, the expense might be justifiable, but if you're just an average guy (Joe the Gardner?) spending close to $100 or more to see where your lawn needs watering or is otherwise stressed seems rather excessive. So I looked for other options.

These glasses aren't complicated electronic devices such as night vision goggles, but rather purple colored lenses that filter light. The expensive glasses claim to have be NASA designs or something like that and probably have better tuned filtration to increase contrast or something along those lines. I own a pair of sunglasses that had NASA technology in the lenses. I didn't know that when I was trying them on. I just knew they let me see the best while blocking out light. They were the brightest pair I tried. Very expensive, but worth it in my opinion since I'd wear them frequently.

The way the glasses work is they use a purple colored lens to filter out green light. Green is opposite the color wheel from purple, so a purple filter will block green light making green light appear darker.

Plants absorb red and blue light and reflect green light, which is why they are green. When a plant is stressed it doesn't use as much red and blue light in making food, so it reflects more of it.

Sounds like a good idea.

The University of New Hampshire has a page on plant stress filters, including some example photos, and even a cardboard glasses template you can use to attach the purple filters. When you walk around your lawn with the cardboard plant stress glasses on, make sure you're munching on a bag of popcorn and every once in a while quickly duck out of the way of some oncoming 3D object just to mess around with the nosy neighbors.

If you don't know where to get the purple filters locally, they are available through Amazon. Click on the picture on the right to order a sheet. It's very inexpensive and one sheet is enough to make a number of glasses and camera filters.