Yesterday I decided to pull dandelions from my front yard. I used the same method my parents taught me - take a screwdriver and try to pull the dandelion plants out with the roots. I rarely managed to get most of the roots. I wondered if there was a better way to get rid of the weed.
(On a side-note, I really do not mind the plant. But my neighbors probably do not want dandelion seeds from my yard blowing into their yard.)
Here is what I found:
UC Davis recommends mowing and watering the lawn appropriately to prevent weeds from becoming established. They recommend watering to at least 6 inches down - up to three times a week in hot climates. They actually recommend that the top two inches of soil be allowed to dry out (unless the grass is new and is getting established). Letting the soil dry out makes sense, as this makes it hard for weed seeds to establish themselves.
As for mowing, UC Davis recommends taking no more than 1/3 of the blade height each time the lawn is mowed. This may mean mowing more frequently, but it keeps the lawn healthier. Having a healthier lawn makes it harder for weeds to take hold.
If dandelions (or other weeds) do grow, UC Davis recommends hand weeding. They recommend removing the entire root. Next time I weed, I will take their advice and try a tool they recommend called a dandelion fork. It is similar to a screwdriver, but has a forked end. I will also water the grass well beforehand so that the roots are easier to pull out.
Another UC Davis page,( http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7469.html ), mentions that dandelions can sometimes regrow from just one inch of root. Since the roots can be 6-18 inches usually, and possibly up to 15 feet ( http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7469.html ) getting the entire root can be difficult without watering the ground first.
Even if you do not weed, be sure to pick the flowers. Giving a kid 5 cents for every dandelion flower he picks out of your own yard would help prevent the next generation of infestation.
Other websites had ideas such as pouring vinegar over the dandelion. I figure that you might as well as pull the plant up if you are going to go through all the trouble of hunting each dandelion plant and pouring some substance over it. None of the organic options are guaranteed to work, anyways.
My favorite idea that I have come across several times is to think of it as "harvesting" dandelion greens instead of "weeding." The greens are edible by humans and critters like rabbits and chickens. Enjoy digging the dandelions up and eating them.
Since I am a little bit skeptical of my ability to make absolutely sure I'm eating something safe, I just placed the root of the dandelion plant in the compost bin that the city will pick up. I left the leaves on the lawn do be mowed and turned into mulch.