Question
Hi, I have been a dog trainer and have boarded dogs in my home for many
years.  I recently started to put in ornamental shrubs and trees.  My yard is
difficult.  It's mostly shady with partial sun and the soil is compacted and clay
like.  That being said, I've rototilled and amended the soil with compost.  All
plants were planted wide and deep with peat moss and compost.  There are a
couple of trees in my yard so the resources may be taken up by it.  Anyways,
my shrubs are not thriving.  They just don't "burst" out.  If I do any one thing
wrong, they go brown, or they fungus (dogwood).  I am wondering if there is
too much acid in soil when dogs were allowed to pee.  I fenced off the area so
they can't get in there now.  Do I need to dig up a foot of dirt and put in new
top soil.  Is the urine still in the ground?

Answer
Odds are your Dogs are NOT to blame for the poor state of your sad Tree.

Dog Urine is primarily Water plus Urea -- Nitrogen -- produced during metabolism of amino acids.  Most mammals and vertibrates produce Urea (H2NCOH2N).  Birds and reptiles produce Uric Acid (C5N4O3H4).

Let's look at Urea.  The stuff in Urine.

Dogs naturally tend to eat a lot of protein (although they eat a less protein than cats).  The result is a high amount of Urea present in the dog's urine.  And it's the Urea that burns the Grass.  Not the pH, which can go as low as 5.5 for most Dogs.

We know that Clover is somewhat tougher than most Turfgrass when it comes to soil numbers.  But what exactly are those numbers when you have regular canine treatments over a long period of time?  One Florida resident asked that very question, and decided to get the answers out of his own back yard:

http://grove.ufl.edu/~turf/epaper/beck.html

There are a few details here to note from that Florida experience.  One is the amount of Urine produced by the 108-lb. Dog: at 20 ml per pound of weight per day, the Dog in the Florida study was pouring 2160 ml of Urine on the Grass -- apx 0.56 gallons every day.  Another point the author makes is that the pH of soil taken from the area where the Dog pee'd tested at 4.3 to 4.4; the pH of soil in the area where the Dog was not allowed, 5.7 to 6.2.

But the most striking statement in that Florida backyard experiment was about the effect that Dog Urine seemed to have on growth of a certain Weed:

'The areas in the pee zone, have a nice stand of goose grass, Eleusine indica.  Hell, my Goosegrass is greener than some of my neighbors front yards.'

Since you do have a Dog, you should do what you can to withhold unhealthy pesticides and weedkillers.  They're not state of the art, anyway.  My guess, however, is that you are using one or both, and they are taking a toll on the Tree.  Note also that neighbors using Round-Up may be shrugging off the curtain of gas that floats toward the property line and over it into your neighbor's tree and the tree is now history.

If you supply your local Zip Code, I may be able to tell you more (by knowing what you need and what you are working on).  'til then, Thanks for writing.