Question
I have a back plot of land across the driveway in the rear of the house.(Philadelphia, Pa).  It is approximately 27X22 FT.  It got way over run with weeds these past couple of years that I have owned the house.  On top of that last year I dug out about 12 azailia bushes and I have a dog that does her business back there so there are alot of barren patches and places with just weed growth.  What type of grass for both the geographic area and one that can take a canines urine without burning?  I know I have to till the soil how deep should I go?

Answer
I'd say you have one doggone problem, mister. We have always had dogs in our house - but they were banned from the garden. Too much digging, too much hunting, too reckless and, as you have noted, they can burn the heck out of anything growing back there.  It's not always a matter of when Nature Calls.  Often it's the calling card they want to leave to tell everyone Fido Was Here.  

Believe it or not, this problem has been studied. One researcher tested a handful of grasses; a fescue grass variety Kentucky 31 came out on top, followed by Ryegrass, with fussy Kentucky Bluegrass coming in last. Experts at Seedland, my favorite grass seed supplier, have slightly different advice: "In general grasses that spread by either rhizomes and/or stolons are the best choices as they tend to repair more easily." Seedland recommends Kentucky Bluegrass as the grass of choice for dogs. But even the best performers unfortunately are not going to be damage-free.  Dog urine is highly acidic and damage is going to occur no matter what you grow there. If you must let your dog out back, consider following him around with a hose and diluating the spot right after the dog has pee'd with a few seconds of water from the hose. In theory at least, this would convert the waste into high nitrogen fertilizer that's good for the grass.

To plant your new lawn be patient. Throw some alfalfa seed down and let it grow all season without mowing.  Let your dog do whatever he likes.  Then in the autumn plow it all under with some lime and leaves, and sow your favorite grass on top. The azaleas would have been most successful in soil that is way too acidic for grass so pay special attention to that section when you are putting down your lime.  If you can wait that extra season to sow, you will have some excellent topsoil that needs a lot less work and grows green, healthy grass.  Gardens Alive can provide several choices of fertilizer and weed killer that will not hurt your dog, or any of the children that play with them.    

You can check out the full Seedland position on this matter: http://www.lawngrasses.com/  Look for the section on Dogs.