MY son's dogs starts each day by urinating on all my trees and shrubs. These include hollies,mountain ash and a bradford pear. Is there a spray I can use to keep him away. Thank you. Jim McManus

Dogs pee on trees... that's what they do! He is marking his territory. There isn't a spray to stop this, you can only use other alternatives. First of all, is the dog neutered? If not, this would be your first step. Second, tell your son, yourself, or another household member to get up first thing in the morning, and take the dog for a good long walk. The sooner the dog gets out, and walking, the less he will be peeing on your trees.

Is he doing any damage to your trees? You could put a barrier around them, you can buy plastic mesh that rolls out around the base of the tree.

If you spray the area you are getting rid of his scent and he's just going to mark over top of it again.
One of the downfalls to male dogs is they cock their legs on anything!

Look on the bright side... at least he isn't killing your lawn

My dogs have always done that, to the point where one would mark and 1 min later the other would mark and back and forth on the same tree. (they were both fixed) so I put my fruit trees in big pots. I wasn't worried, I expected it.

Very true, he is marking his territory and if there are other dogs in the picture it becomes a dominance/alfa trait even if the other is a female. My male was neutered literally within days of the testicles dropping and wasn't around any males to learn the behavior of lifting his leg to wee wee so it's the funniest ever to see him squat to wee wee like a female. People see him and just laugh, I get the last laugh cause I don't have to deal with the lift the leg routine like they do.. lol :p that does get awkward cause the PH level in urine burns grass and shrubs.