Weeds continually frustrate master and novice gardeners alike. While flowering weeds may be pretty, they're designated as weeds because they're growing somewhere you don't want them to be. The first step in controlling your garden weeds is learning what they are, so you can target them with an effective manual or chemical control and prevent them from cropping up in the future. Flowering weeds can be easier to identify than grass-like weeds because they're generally more unique in appearance.
Take a picture of the weed with your camera so you can easily compare it to images of flowering weeds in weed identification databases.
Count the petals on your flower. Write down their arrangement, color and other characteristics. Does it have a different colored center, like the black-eyed Susan? List everything that makes this weed flower unique from others in your yard.
Examine the flower's leaves, noting their color, texture, size, shape and arrangement along the stem. Take notes.
Consult university weed identification databases, plus the Weed Science Society of America's weed identification database. These photo galleries provide images, text description and location information about many types of flowering weeds. Make a positive identification of your weed flower from these lists.