Get a cold drink, Biggirl, and I’ll tell you a story.
Many years ago, I bought a house. It was my first house, and most folks would pronounce it to be a shithole, which it indeed was. However, it was an affordable shithole, and I learned much in the 15 years spent there. In the first week after settlement, basic yard cleanup filled 13 of those big honkin’ 50 gallon trash bags. The two guys on either side of me piled my bags with their trash to get rid of it, so happy were they to be rid of their obnoxious neighbor. The contents were: tires, a bowling pin, clothing, undergarments, knives, appliance parts, automobile parts, window frames, broken glass, beer bottles, cans, parts of a swimming pool filter, part of an above ground pool, lumber (rotting), prescription pill containers, and other items which defied proper description.
The remaining vegetation consisted of: two fruit trees overgrown with suckers, some dead bushes, a hedge, and an irregular lumpy melange of weeds. The dead bushes were removed via a Ford truck and some towing chain, the fruit trees trimmed of suckers, and the hedge was contemplated. Forgot to mention that the hedge had actually grown up and through some crappy and now badly rusted metal fencing. I had my one buddy with an industrial duty roto tiller come over to do the back yard in preparation for reseeding, and then we found rebar. Have you any idea what a 20 horse tiller does when it hits 5/8" and 3/4" steel bar in 12’ lengths? My buddy damn near messed himself when the machine began its ugly dance. The rebar unearthed, we completed tilling, I raked things quasi-smooth, and seeded. At this juncture, I learned that my home was situated on ancient burial grounds, and disturbing the soil had angered the gods. They wept. For days. And more days. Yet more weeping from the sky, such that what seed not immediately eaten by a plague of birds was washed into my side and front yard, forming a brown miasma, as if I’d administered a high colonic to some huge beast behind the house.
A slightly less lumpy crop of weeds soon sprouted along with a possible chance of grass. Once the green collection of growth needed mowing, it became apparent that the two fruit trees were only going to produce one thing, that being intoxicated wasps. Miniscule fruitlets, resembling the spawn of an ill-begotten experiment at Del Monte would form, drop, and rot. Winged angry insects, drunk on their ground produced pruno, made lawn mowing a task similar to dancing the fox-trot in a mine field. Re-enter Mr. Ford with the towing chain, and that problem was abated.
Seeking further enjoyment, I turned to the nasty looking hedge. It wasn’t one species, instead appearing to be a mixture of boxwood, thorny something, and mystery plant. One weekend, my then girlfriend and I attacked this evil growth, and together hacked, sawed, dug, and pried out of the ground the entire foul 30 feet of it. We’d just about finished bagging it all up and were ready to enjoy a much needed shower when the neighbor came home and reacted to the sight with horror. Remember the movie “Alien” and the scene where the critter bursts through Kane’s chest and scampers away? Same look. :eek: Turns out the aforementioned mystery plant was none other than Toxicodendron vernix or Rhus vernix, better known to most folks as poison sumac. The decontamination shower proved to be grossly insufficient, and we spent the next week consuming methylprednisolone, avoiding contact with one another, and generally bitching and itching. Great mid summer fun in a house bereft of air conditioning.
Having learned my lesson, I did nothing further to the grounds, other than spread the weed and feed stuff, and take my pet Lawn Boy for a weekly walk around the yard. That place was 12 years ago, and although I have a newer pet Lawn Boy, walking him at my present abode is about all I do, lest I bring down a new pestilence upon my head. 
Good luck.