Vacant Lot Help

I have exclusive access to a 4,000 sq ft vacant lot next to my apartment building in Brooklyn. I doubt I'll be living here more than 3ish years and don't own (or even technically rent) the lot so I need to keep expenses to a bare minimum. When I first gained access to the lot (last summer) it was FULL of 6'+ weeds, lots of trash, and an abundance of concrete chunks. I removed the trash and concrete, rented a brush mower and took down all the weeds, raked and bagged all the debris, and then spent countless hours on my hands and knees literally pulling up all the weed roots throughout the lot. When I was done I had a relatively flat bare lot but the soil is full of rocks.

Cut to this spring. Not only do I have very rocky soil but practically all the weeds have grown back and are already 5-8" tall! I can't believe all the tedious back breaking labor of pulling up the weed roots last year didn't handle this issue. My original dream was to have a nice 4,000sq ft lawn with some patio furniture and a grill picked up from Craigslist but if getting this lot ready for planting grass is going to have to cost me an arm and a leg I might have to admit defeat.

From what I've seen and read I'd have to purchase a number of rolls of black tarps to smother the weeds and then cover it with 2" of clean topsoil. At 4,000sq ft this is far too expensive. I've also read about sheet mulching with cardboard. It's going to take forever to get enough boxes to cover the area and I would still need top soil. I've considered renting a tiller but if pulling out all the weed roots last year didn't fix the weed issue I have my doubts about the effectiveness of the tiller for this and I'd still end up with a super rocky lot (unfortunately the rocks aren't just on the top either).

I guess this is just an opened ended question about what the most affordable and effective way of getting rid of these weeds for good and prepping this lot to be able to be seeded?

The soil will have a massive bank of seeds sitting there, many weed seeds sprout when exposed to light- so by removing the weeds you encourage those seeds in the bank to germinate. This is why sheet mulching works- cover up the weed seeds and they don't germinate, and eventually they will rot.

Some weeds can be outcompeted by grass- so sew grass seed and let it grow tall and it can outcompete the weeds. Won't work for tough perennials like burdock and things though.

Having said all that I don't have any suggestions on how to do the whole lot at once! On my plot I work by covering an area with old carpet to kill the weeds, leave it for a season then remove the carpet and plant it up with whatever plants I do want- and move the carpet onto the next patch- a very long term solution!

My recommendation would be to divide and conquer. Divide the area into different zones and do different things with the various areas. So, for example, select an area that you would like to have the walkable grass lawn. This area may only be 300 sq' or so. Perhaps it would be the area with the least rocks, or the most shaded area, whatever you would like. Then for another area, you could broadcast wildflower seeds and let that area go. In another area, and I would highly recommend this idea, find a source of free wood chips and cover the ground with at least 3" or so. Laying down newspaper or cardboard first would be even better. You could plant some cool annuals in this area. In another area you could plant some fast growing ground cover, like sweet potato vines, pumpkins, or something like that. I'm sure you will spark some other great ideas from others in this thread, so when you do, consider incorporating several of them. Using various strategies in different sections would probably make the endeavor more manageable. Post pictures. It sounds like a great project.

For quickly sourcing enough material to cover the whole lot, I'd recommend you ask at furniture and appliance stores. Not only do they get in lot's of boxes with their products, the larger the box the less edges for weeds to poke up through. I work at a grocery store and have been able to get large amounts of boxes there, also. But the smaller boxes require thicker layers unless you have the time to regularly weed along the box edges.

For wood chips to cover the boxes (which improves the appearance, helps keep moisture in the cardboard so it eventually breaks down, and builds soil for future planting) If you're in the US, I recommend you speak with anyone you see doing tree pruning in your area. They are often happy to dump truck loads of fresh wood chips in locations close to their work that don't charge dumping fees. It saves them travel time, gas, and money.

If you go this route, you can set up your patio set on this area without waiting for grass to be planted. Just tell yourself it's a courtyard instead of a lawn.

Matt Martins wrote:My original dream was to have a nice 4,000sq ft lawn with some patio furniture and a grill

That seems easily achievable to me. Just start mowing. The species that thrive under those conditions will grow well. Those that don't like being mowed down repeatedly will die out. My definition of "lawn" is an area that is mowed regularly. I'm not too particular about what species are growing in the lawn. I really admire the people that maintain wildflower lawns. They cut the area every 7 to 10 days. All season long, some wildflower or other is blooming to add interest and diversity to the lawn.

Here's photos of some of the interesting lawns that have developed around my place.

Why not doing what we call chop and drop?
This would be getting a scythe (has to have straight handle) and just scything the place couple of times/year snd leaving the debris where it is,
also you don't bother with roots.

You'd get great soil by doing that!

I agree with Mr Lofthouse; just keep mowing. Don't let the weeds get high enough to be overwhelming. The more you cut the "lawn"; the more seeds will sprout in the increased sunlight. And you also need to keep the weeds from setting seed.