In a recent "Plant Man" column, a reader asked for suggestions to rid his landscape of snakes without having to kill them. One reader responded with a fascinating (and non-toxic) idea that you'll find in this week's column, below.

You can now purchase Snake Repellent that is safe for use around pets and people.

But first, let's look at some recent questions from readers.

QUESTION: "I have two 3 1/2 month old Bradford Pears. They're part of new construction. About two weeks ago, the leaves started turning yellow and falling off. It's been consistent ever since. Prior to that, the leaves were always green. My wife watered the trees one evening and the next day they started turning yellow. It's been downhill since. Any ideas? There was about a three week period where the trees didn't get very much water before my wife watered two weeks ago. Is it possible that the trees had not gotten enough water, or that we over watered? Thanks for your help." - Kevin Sinclair

ANSWER: It is possible either way! Too much or too little water can cause the problem you describe. If the trees were purchased in containers or balled and burlapped ("B and B") as is often the case with larger trees, you might not have been getting enough water to the roots of the trees where they needed it. Bradford Pears are pretty tough and as long as you can get water to the roots you should be fine. Even if the trees drop all their leaves, they may put back out this next season.

QUESTION: "I planted a Bloodgood maple this year, but the beautiful deep red leaves are now mostly green with red edges. is it the soil or drainage or sun?" Joyce Walker

ANSWER: A true Bloodgood needs good exposure to sunlight to have the deep red foliage you desire. If it is in the sun and it is still green leaved, then I suggest you should go back to where you purchased the tree and let them know.

And now to a message I received from reader E. Stewart, regarding humane ways to discourage snakes from taking up residence on your landscape: "I read the article regarding snakes and have tried many methods since the snake population around my yard seemed plentiful. I used Snake Away, which I bought at Lowe's as well as turpentine and both seemed OK for a time, but this year I simply planted marigolds. "At the time I just wanted them because they're so pretty to look at but a friend told me that they are a natural snake repellant and sure enough I haven't seen a snake in my yard yet this season. And for my yard that's amazing since last year they would even be on my porch and I was afraid to go up my steps at night. I put the marigolds in pots along my walk & porch steps and you can believe next year they'll be there as soon as possible." - E. Stewart

ANSWER: So marigolds are making the snakes move on and find a new habitat! That's a new one on me, and I'm passing it on so other snake-infested readers can decide if marigolds are worth trying. In fact, I've been reading about the benefits of marigolds in controlling mosquitoes, another backyard pest. Some contributors to blogs (Web logs) claim that merely planting marigolds in containers will reduce the number of skeeters in the backyard, so the suggestion above might serve a dual purpose!

However, Mark M. Green, a Polytechnic professor in New York, took the idea one step further. Green and graduate student Jeff Singer chopped up the flowers, boiled them in a pot and dispensed the resulting solution in small containers of water - the breeding habitat of Aedes aegypti. Professor Green said, "the marigold stuff just killed all the mosquito larvae in sight."

Unfortunately the World Health Organization said they thought that Green's experiment was impractical for controlling malaria-carrying mosquitoes on a large scale. You can read the entire report at this web site: http://engineering.nyu.edu/news/2016/07/25/zika-fix-may-be-close-common-...