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Garden Weed Identification

Identifying Five of the Worst Weeds


Japanese knotweed

Picture of young Japanese knotweed plants.

David Beaulieu

For the action-oriented, gawking at weed identification pictures may seem rather lame. Perhaps as far as they're concerned, they simply don't like a particular "volunteer plant" in the lawn or garden and are ready to go pull it up or spray it with an herbicide. They won't "dignify" the plant by identifying it, first, before locking horns with it.

What's wrong with such a disdain for identifying the enemy as a preliminary step to doing battle? Plenty, as you probably realize if you're reading this guide. The most basic objection is that it helps to know something about what it is that you're fighting. Proper garden weed identification can be the gateway to knowledge that has been compiled over the years regarding a particular plant.

Yes, as superficial as a mere name may seem, without it, you're barring yourself from all kinds of helpful tips and warnings. The purpose of the present guide is not only to help you identify common lawn and garden weeds through photos, but also to introduce you to some of those helpful control tips -- and a few warnings, too.

Often, we approach control from a position of ignorance. As children, perhaps, we're told by someone misinformed on the subject that a particular noxious plant is called such and such, but it turns out to be an erroneous weed identification. I myself was told during my childhood years that a particularly loathsome nuisance encroaching upon our garden was "sumac" when, in fact, it was Japanese knotweed (see picture on right). I later learned its true identity, which is important, since there's an impressive body of literature out there on Japanese knotweed control.

One salient fact that speaks volumes in favor of first identifying your enemy correctly is the fact that not all herbicides are equally effective against all weeds in all situations. If you neglect weed identification prior to spraying your foe, you may be wasting time and/or money, and causing unnecessary harm to the environment, to boot. To counteract such an exercise in futility, a discipline named "IPM" has arisen.

Also, by studying up on the plant first, you may discover facts about it that will alter your approach in fighting it (for instance, see below for poison ivy). And in some cases, garden weed identification may even altogether alter your desire for eradication of a particular plant, as you discover its good qualities. Remember a "weed" remains a weed only so long as you consider it undesirable. For that reason, in the following resources, I not only discuss plants that are commonly and justifiably found on homeowners' "hit lists," but also relatively innocuous plants whose designation as "weeds" you may wish to reconsider.

Weed Identification for Five of the Worst Weeds

But there's nothing innocuous about the group of weeds with which I begin. The first three are especially noxious, because they actually pose health risks. These three would probably be commonly found only in gardens that border upon woodland. The fifth (Japanese knotweed) is another that most people wouldn't think of as a "garden weed," per se; but if you're unlucky enough to be gardening on a plot adjacent to a stand of Japanese knotweed, guarding against incursions from this infamous thug becomes nothing short of a way of life.

1. Poison Ivy Pictures

Poison ivy can cause more than just an annoying itch. Did you know that you can develop serious health problems from attempting to eradicate poison ivy by burning the vines? And as commonly as one hears people speaking of poison ivy, proper weed identification for this plant is not as common as one might think. Many people needlessly spray the vine, Virginia creeper, thinking it's poison ivy. Worse yet, many others fail to identify the poison ivy that they encounter when enjoying outdoor activities -- walking blindly into it and paying the price, afterwards. For information on poison ivy, please see my identification photo gallery, "Pictures of Poison Ivy":

Pictures of Poison Ivy

2. How to Get Rid of Poison Oak

If you live on the West Coast of the U.S., that "itchy vine" in your backyard is probably poison oak, not poison ivy. For information on poison oak, please see the following resource:

How to Get Rid of Poison Oak

3. Poison Sumac Pictures

Of the "big 3," poison sumac isn't as widely encountered as its 2 relatives, poison ivy and poison oak (you'll probably encounter it only if you garden near swampy land). But it can give you just as bad a rash. Learn how to identify it by using my photo gallery, "Poison Sumac Pictures":

Poison Sumac Pictures

4. What Does Crabgrass Look Like?

The next two entries won't harm your health, but they are eyesores. The first is the common lawn and garden weed, crabgrass, whose very name suggests how tenacious a foe it is! For information on killing crabgrass, please see the following resources:

5. Japanese Knotweed Plants

The aforementioned Japanese knotweed may be the most widely detested plant that nobody has ever heard of! Japanese knotweed typically takes over areas of a property where the soil has been disturbed. This perennial weed forms dense stands of bamboo-like canes. So what's the problem? The problem is, when cold weather comes and the plants die, the dead canes remain left behind. In fact, it can take years for them to break down, thus creating an unsightly and unmanageable mess on your landscape. For information on Japanese knotweed, please see the following resource:

Japanese Knotweed Plants

Please continue on to Page 2 for further garden weed identification resources, beginning with a plant that causes suffering for untold millions every autumn....

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