"I would like some advice as to what I can do to kill ALL of this plant life"

Egads! You came to GardenWeb to ask this question?

You say you don't have the time or knowledge to care for the landscape plants. And you also say you're going to plant more lawn, and landscape with rocks. Unfortunately, the lawn and the rocks are also going to be a haven for weeds if you lack "time and knowledge" to manage them correctly.

Pour some concrete.

Cheers!

IMO, A Lawn is typically more work than landscaping.

A landscaped bed should be mulched maybe one a year...or less. A landscaped bed could be mowed once a year...

I've been working on slowly turning my entire yard into landscaping so I don't have to maintain a lawn.

I also saw this posting and thought, as did redneck grower, "what on earth would prompt this person to ask lovers of green things how to kill them all?"

I'm also curious why you bought a house if you didn't want to deal with the land that invariably comes with one.

You'll be needing to spend quite a bit more $$ to re-do this whole thing than you would in just tending what you have. But it's your property.

And I don't mean to be hostile, so forgive my snarkiness.

I think xeriscapes using ornamental grasses and a lot of flagstone patios and pathways would be your best bet. Lawns take a LOT of maintenance. As far as what would kill everything, get some contractor-quality rolls of black plastic (they're available at Home Despot) and just roll it out atop everything.

Oh I don't know. It sounds like there already is some lawn, and if the poster knows how to take care of a lawn then a larger lawn might be easier than mixed lawn and landscaping. I love the landscaping that came with my house, but it does require care as it ages, and usually research to determine what kind of care. Getting 10 yards of mulch spread around, pruning all the bushes and trees, digging and dividing bulbs, keeping the lawn from invading the beds, replanting where things have died, raking leaves out of the mulch in the fall, protecting roots from the frost, fertilizing and composting, and lawn care starts to look not so bad...

Covering it all over with plastic sounds like a good idea for this poster. You can mulch over that with rocks or bark if you don't want to stare at plastic all summer.

Following up on the black plastic smother...

I bought about a 1000 sq. ft. roll of 6 mil plastic last weekend and unrolled it on a moonscape (if moons were made of sand, random rocks and weeds) of a backyard. I am hoping this murders everything underneath it. I'm told it should be about a month - does that sound right? And then I'd read to till it afterward, but when I mentioned that approach to an arborist I happened to be talking to, she looked horrified and informed me I'd be tilling weed seeds right back into the earth. Okay, so what should step 2 be? And if my soil is sandy, can you improve it with having topsoil or something brought in? Or best to work with what you have? Oh, and step 3 - landscape fabric + mulch going forward?? Many thanks for advice.

Yup, don't till it. Tilling brings dormant weeds seeds to the surface, so they will sprout.

Step no. 2 should be a layer of compost for your soil amendment.

And Step No. 3 should be mulch.

Whacking the shrubs increased the amount of sun which probably increased weed seed germination. Sounds like you want paving stones or something similar that harbors little organic life.