Grass and weeds can be difficult to eradicate completely but several cultivation methods and chemical controls, implemented at the correct time of the year, can reduce their re-emergence. Although difficult to eliminate in one growing season, with continued practice weeds and grass disappear, making your growing area easier to garden or resow with the desired plants.
The most effective methods of eliminating weeds is to reduce the conditions in which they thrive and reproduce. A thick lawn with a good coverage will prevent weeds from popping up by preventing light and water from reaching them. Mowing the lawn regularly prevents weeds from releasing seed.
Pre-emergent herbicides kill the seed of the weed before it is given a chance to germinate. Pre-emergents are used to kill certain types of grass and grassy weeds as well. Grasses that are thin may require an annual application of pre-emergent herbicide to control weeds properly.
Covering large areas of a lawn with black plastic will kill off any weeds or grass that attempt to grow in the area. Black plastic traps the heat of the sun, scalding the plants underneath, while blocking the light they need. Weeds and grass under plastic will die after a four to six week period. They should then be pulled out of the ground to prevent recovery.
Flame and Heat
Flames or heat can be used to control the spread of grass and weeds. Boiling water poured onto weeds or grass sprouting out of cracks in a pavement will be killed almost immediately. Propane backpacks that shoot fire, like a small flamethrower, control weeds and grass by burning them back to the ground. Burning weeds and grass will make it difficult for them to recover.
Post-emergent herbicides kill weeds once they are grown. Chemical controls prevent spreading of seeds and destroy the plant when absorbed through the leaves. According to the University of Minnesota, liquid sprays are more effective than dry, due to their absorptive quality.