Step 1: How to Stop Weeds
Most big agriculture in USA depends on chemical herbicides that change plants internal chemistry and causes the plants to die of malnutrition. Mainly this comes down to Monsanto and their flagship herbicide RoundUp. Roundup ready plants are GMOs and not generally availible to the general public. Plus nobody really needs mre chemicals and thats probably why most folks grow gardens themselves, including me so were gonna forget this method.
Second effective method is mechanical means or removing weeds. This can be hand pulling, hoeing, tilling, and so on. This is hot, messy, hard work. It also needs to be kept up with or you can lose everything in the mess.
My favorite method is weed barrior method. This basically means something on top of the soil that stops weeds from growing through the soil.
Step 2: Weed Barriers
A common used barrier is grass clippings or mulch. This works by covering the topsoil and weeds to block light stopping growth. The pros of this method are that mulch can look great and is easy to get and spread. The cons would be that weeds will eventually sprout and grow through it and the colored varieties will need replaced and all will break down and need more put on top.
Another method I have seen is putting newspaper or cardboard down under mulch or clippings to reduce the chance weeds will sprout or root through the mulch or grass clippings.
This does work pretty well but eventually the cardboard breaks down and still has weeds. Also this makes a pretty big mess to clean up. With moderate winds the mluch or clippings can blow off and then the cardboard also then blows away causing more mess.
A more soild system that weeds cannot penetrate is concrete pavers. Weeds will not grow through them, although they will grow in the spaces between blocks. They can look great or at least tidy and create a good way to walk through the garden. They do not brake down unless one gets broken, and can be used year after year. The biggest downside is that they add up in cost quickly. The offset is that they work 100% and are a long term investment.
So what's the best? Classically I saved it for last. Plastic. I know, i know, plastic is bad for the environment, but I'm not talking about the expensive, huge rolls that are availible at home centers and hardwere stores. Plastic already exhists in massive quanities so.... How about I tell you of a great way to recycle plastic and help make gardening and landscaping low maintence.
Lumber Tarps. Interior use lumber and plywood is shipped wrapped in a heavy plastic material that isn't very different(maybe a littke thinner) than any other tarp you can buy at the store. You know what most lumber yards do with the shipping tarps? throw them in the dumpster. My local yars keeps a pile on hand to sell and then dumpsters them, i assume most others follow suite.
So how expensive is this trash? my lumber yard sells them for $2 a tarp. Now since im buddies with the lumber guys and they all know every so often they are gonna have to spend a chunk of the day throwing these tarps away (and the managment does too) of i pay for $6 for three tarps i generally go home with about 10 or 15.
Your milage will vary. I would go to the local yard and ask if they have any. If they do ask price. Offer a few bucks for their trouble even if they say free. They are generally trash so I would guess this should work most anywhere.
Step 3: How to Use Lumber Tarps
To cut a tarp i usually use a razor knife or box cutter. Sissors also work ok. I generally cut the peices of tarp bigger than I need and fold them under to get nice clean edges.
To create the holes for the plants just cut and X in the tarp.
For the edges I like to use concrete pavers, retaining wall blocks or landscape timbers. These edge treatments Really hold down the tarps and help keep everything looking great.
Other good methods include landscape staples or just some rocks or bricks near the edges. Landscape staples can easily be made out of galvanized 14awg fencing wire. Bonus the staples hold down hoses nicley as well. One thing to consider with holding down the tarps is that you dont want to poke may holes in it as each hole is a potential weed breach point.
Dealing with holes or tears... Often lumber tarps will have staple holes and other tears from being ripped off th lumber. When buying try to weed out the bad ones but maybe take a torn one for patch material. When laying down the tarp and you have a hole place a patch that extends a good ways (6 to 12 inches) beyond the endes of the hole on the ground first. Then lay the main tarp over the patch. Lay a decent rock or paver over the patch so it doesnt slip out or some landscape staples. When I use gravel over the tarps for landscaping i just hold the patch in place with the gravel. Often times you can find tarps that don't need patched though.
Step 4: Garden Example
I was lucky and got a tarp that covered 20ft plus long boards which allowed me to use 1 single tarp to cover the entire small garden.
Step 5: Landscape Example
I love using it for flower beds and around the edges of my house. To keep the weeds from growing up through the rocks...You guessed it, lumber tarps. Any plastic sheeting would work but why spend a bunch of money when the tarps are so cheap and basically the exact same.
Step 6: Watering and Tomato Cages
I have switched to soaker hoses with timers. Soaker hoses only water the direct area they touch keeping most of the water right on your plants. I wrap the hose around each plant once or twice. The timers help keep me from over watering the soil and wasting it.
Another positive of the plastic lumber tarp is that water travels down it instead of soaking into the soil. I also have my garden set on a slope with the plants in a ditch. This way all the water that doesnt soak into the top plants hole in the tarp runs down to the next plant and so forth. This just increases the effectiveness of the soaker hose.
I also use a combination of classic tomato cages and some cattle fencing panels. The pannels act as a trellece and I then train the vines to grow through and up the panel. The cattle pannels are very cheap uses at auctions. They commonly sell for 2 to 5 bucks a pannel.
Step 7: Results
As you can see some vines are springing up at the edges from traveling into the tarped area but 99% clear. As a reference we have mowed around 4 times since these were planted and have had a crazy amout of 10 inch plus dandelions.
The next step shows photos of the edge where i mow near the garden. it would be an idea of how much I would have needed weeded if it wasn't for the tarp.