A chemical-free alternative to killing weeds
The process known as Solar Weed Control is lengthy but it gives you the ability to kill weeds without the use of chemicals.
The process is simple. Simply water the area you desire to be weed/flower/plant free and then cover the area in clear plastic. Let the plastic sit for a couple of months and VOILA. The majority of your weeds should be gone.
Read about natural alternatives to weed killer