You have heard time and again that identification of a pest problem is half the battle. Correct identification will allow you to research the proper control for the problem. There are some weeds common to nearly all 50 states, then there are those found only in small geographic areas. The following resources should help make the job a bit easier.

  1. There are some Web sites that offer weed identification. The best is a product of the University of Illinois and the Illinois Council on Food and Agricultural Research. The site contains a key that allows you to choose characteristics of the leaves, stems, roots, flowers, etc. As each characteristic is chosen, a list of possible weeds develops along with photos. There are 172 species included in the list. The list of weeds and photos can also be used without the key. Visit

  2. Next in line is the Web site from Virginia Tech. The site contains a long list of weeds and their photos. There is a key for identifying grass weeds, but not currently for broadleaf weeds. The key is navigated by answering a series of questions accompanied by photos depicting important identification traits. Because grass taxonomy can be difficult, having the photos is helpful. For example, there are good photos of ligules and auricles. Words that taxonomists are familiar with, but are sometimes unknown to the very people providing the service. The only drawback to the site — if you make a mistake, you will need to restart the key. Choosing the traditional “back” button will take you to Internet “no man's land”. Visit

  3. is a Web site courtesy of PBI/Gordon. There, you can see monthly updates on weed problems in your region of the United States. In addition, you can check the average germination dates for specific weeds in a specific geographic area — very helpful for planning ahead. Unlike many of the other Web sites, there are written descriptions of plant growth habits, flowers and information on what type of conditions the weed thrives in. Visit

  4. There are many more Web sites sponsored by various universities with photos of weeds common to their states. With most of these, you will need patience to scroll through photos, as there is no help getting you to the correct photo. The major benefits are fairly easy access and the cost savings of not having to purchase myriad identification volumes. If your business doesn't have Internet access or if you have resisted learning how to turn on the computer, you should find access and assistance at your local library or ask one of your younger employees for assistance.

  5. Use your local resources. University Extension services have color publications listing problems for your state. They also cooperate on a regional basis and publish guides that apply to several states. Check in your phone book under county government listings to find the source nearest you.

  6. Most herbicide manufacturers and distributors have picture sheets and publications available, just for the asking. If your representative doesn't have a supply in the car, they will make sure to send them to you.

  7. While building up your library, also check out books on wildflower identification. These are many of the same species infesting your lawns and landscapes. Many of these references have a dichotomous key to assist you in your efforts.

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