here is a photo of our backyard for reference

Years ago we had friends who bought a house with a hideous looking yard. They hired a Tru Green type lawn service and had a great looking lawn in less than a year, then took over lawn maintenance themselves. Even if you do that, you will have to pick up dog poop very frequently and contain dog pee to a small area. Sod does not root well and last long unless it is installed over sufficient tilled/loose “good” soil with proper pH and nutrients. And it does not like dog poop and pee either.

Watch your dogs when they go out to do their duty… note that one will go where the other went, almost right on top of it. Also, most likely they keep going in the same area. Sooo, block off the yard except for that area. Next, round-up what is there. (I can hear it now…..the world will come to an end if you do that…. on and on) Remove the dead stuff and rent a tiller. While tilling you could include some organic fertilizer (Milorganite for example). Organic so it doesn’t burn the roots of the grass.

Since you are tilling in the fertilizer use twice as must as needed…. When those roots get down to it they will love you for thinking of them.

Sow your selected grass seed..... water it and keep the ground wet, but not soaked. You don't want the seeds that are just opening up to dry out. Another good reason to keep the dogs out of the area.

Keep the dogs out of the area until you’ve mowed it a few times. Remove the barriers except those that surround the ‘pee area’. Keep it blocked from the yard.Make sure the dogs still go to their area when you let them out.

Now that is going to take some doing on your part but after while they should still continue to use it. Sort of like putting newspaper down for them when they were pups. Of course if they are old dogs then forget it…… enjoy the new lawn but watch where you step…. lol

If the above works you could plant a hedge around the pee area so it's blocked from view.

Stay safe

Thank you for taking the time share your insights. I think training them to use a smaller portion for bathroom use is a fantastic idea! We were both intimidated of tackling the backyard with no experience and not quite sure what the first steps should be. Now I think we have a good idea of where we can start. Take care! (:

Check out ‘Caring for New Grass Seed’ posted by cardinalsfan23 as it has some very good info. Mainly it suggests you wait until the cooler weather sets in, around August/September time frame for planting the grass. In the mean time the dog training and some Round-up could be taken care of. A second round of Round-up should wipe out most of the weeds before you plant. A little Weed-B-Gone after the grass is up and running should take care of most weeds.

Have fun....