So we just had lots of sod installed this summer and my backyard backs up to a large field. We have no intentions of installing a fence because we enjoy watching the deer and occasionally foxes back there. The problem is that the weeds from the field have begun to creep up to the edge of the grass. I thought about putting a line of patio pavers or buying the rubber edging border material at the hardware store, but as I have mentioned before, I'm, let's call it frugal (my wife has other terms but we'll stick with frugal). The cheapest (free) way I could think of is to use old tire treads and bury them to make a weed free border. The other nice thing is that tires can conform to virtually any curve in an edge. I called the tire and lube place down the street and asked them if they had any old tires I could have and after he laughed he said "I'm sure more than you could use, come help yourself." So I headed over grabbed a few to experiment and headed home. I looked all over the web to see if anyone had any good DIY's on this idea and I couldn't find really anything so I figured I would share.

Step 1: Supplies and Tools

Supplies:

Used tires. I found the easiest tire was the tire with the smallest tread width when you have to bury it. In other words don't get big truck tires.
A 2x4 or similar and some kind of weight to put on top of it.

Tools:

Utility knife
Electric rotary type saw (I used a Dremmel SawMax), jigsaw or similar with a metal cutting blade. Alternatively you could use a hacksaw if you're feeling the need to get a workout.
Straight edge garden spade shovel.
Sledgehammer
Never forget Safety Glasses and in this case hearing protection and a mask.

Step 2: The Dirty Work Part 1

To begin you have to determine your approximate length of edging you will need. Then assuming an average sedan tire is 26-30 inches in diameter we can use the formula for circumference 2πr and voila we have roughly 87" per tire of edging material. Or you could just ask Siri.

Start by cutting the tread. To do this I used the aforementioned SawMax and slowly cut a progressively deeper line across the tread. Don't rush it as you could potentially catch the tire on fire and it produces a lot of nasty black smoke so make sure to do it in a well ventilated area. Yes, sparks will fly but that just makes the cool factor go up if any neighbor kids are watching. There is no need to cut down into the sidewall, just the steel belting portion.

Now you will need to use the Utility knife (new blade) and begin to cut around the sidewall of the tire as close to the tread as possible without getting into the steel belting. It cuts remarkably easy. What I found to be the easiest was to make my initial cut around applying even but not very hard pressure, followed by a second time around and that was usually enough to cut the sidewall away. Some ideas for the sidewall; use it as a tree surround to keep weeds down or make a cool playground piece like the picture above. Be creative.

Step 3: The Dirty Work Part 2

You should now have a long piece of tire tread. I placed my treads in the hot sun under a 2x4 with two buckets of dirt on top for about 30-45 minutes to help convince them to lay flat(ish).

At this point you could even spray paint the tire to whatever color your heart desires, brown, green, hot pink. The choice is yours.

Determine where you are going to place your edging and lay the tire next to the area to make sure you dig a long enough trench to fit the tire completely.

Using your garden spade, create a trench deep enough and wide enough to fit the tire so that as I chose to do a few inches stick up. You could just bury the thing as deep as you want but as you can see in the picture, I have aggressive weeds that I didn't want climbing over very easily. Slowly lower the tire tread into the trench with the tread facing in the direction where it will be least visible. I found that I had to use a sledgehammer in a few spots to convince the tire to go in a little deeper.

Last step is to stomp the sod and surrounding dirt up against the tire and backfill any voids.

Boom, you're done!

My apologies for the very unPinterest-like photos, but hey, I'm a minimalist.