Black plastic can be a great method of soil sterilization but it will take several months to effectively superheat the soil and kill not only the existing weeds but the hundreds of thousands of seeds that lay dormant. So if you use this method I would suggest you wait until next spring to reseed. If you’re in a bit more of a hurry you could try Corn Gluten Meal, a non-toxic, fertilizing weed killer, so if your lawn is primarily weeds it should kill out the majority of the weeds. Also effective is another organic weed and grass killer made from clove oil, vinegar and lemon juice, called BurnOut. Given the size of your lawn you might consider a combination of treatments, killing out a portion this year and using the black plastic method for the rest for next year.

That said, with a heavily weed-infested lawn you will not kill all the dormant seeds so you will need to consider the use of some form of pre- or post-emergent weed killer for a few years until the new grass is thick and strong enough to fend off the weeds.

Once you have killed the weeds it is best to rake the debris away and destroy. I would not even add it to a compost pile unless you have one that can superheat for several months to make sure all the plant material and any seed are indeed inert. Beware of tilling the ground too deeply, as you will be disturbing not only your top soil content and bringing any subsoil to the surface but also enticing those dormant weed seeds buried deeply to wake up and germinate. Instead, a light tilling to loosen the soil surface is best. If you’ve tested the soil either with a home test kit or by sending a sample to a testing facility (your local extension office can direct you to a qualified lab), then you can make any amendments needed. However, most turf grass will grow just fine in the soil provided, as long as it has sufficient sun and water to germinate and a loosened surface to grow in.

My soil is heavy clay and I have not amended any of the soil, except where I had to raise a level to control water ponding. Adding some peat or other organic matter is OK, but trying to fool the grass into thinking it’s someplace better will cause the roots to never leave that amended area and sink deeper into the normal soil, which is where they need to be to tolerate drought times and long cold winters.

Along with soil make-up, you should know the drainage of the lot. When it rains does water pond and then stand or does it drain off quickly?

If you have underground utilities in your area, remember to call before you begin this project. You don’t want your neighbors upset because you just interrupted their cable or phone service, as they do not bury cables more than an inch or two below the ground!

As for the type of grass in your area, cool season grasses would be the best. Some of these varieties are Kentucky bluegrasses, fine fescues and turf-type perennial ryegrasses. You did not say whether the lawn was all sun or partially shaded so make sure the blend you pick is a mix for the correct light and durability. I have a very shady lot so I prefer fine and tall fescues, but if you have more sun, consider a blend of different varieties of Kentucky bluegrasses and fine fescues. By using a blend of varieties you will lessen the impact of any pathogen that affects a specific variety, or a weather condition that might affect specific grasses. For instance, some of the fescues are not tolerant of hot, humid summers. If you are in question as to the specific blend to buy you can also contact your county extension office for that information. Most grasses are blended for the specific region; you just have to judge the sunlight and the wear. You mentioned dogs, so pretend you have half a dozen adolescents running about 24/7 when looking at the durability!

The best time for reseeding is right after Labor Day, and second best is right after Easter, so consider putting in the prep time this summer for fall planting.

As for nematodes and Milky Spore, these are generally used in the battle against grubs. If you’re not having a problem with grubs then I would concentrate first on getting the lawn developed, then see if these treatments are needed.

Good luck!