All About Weeds

A woman with red boots digs.

Mankind has been battling weeds ever since we first began cultivating the land. Over the years, a number of myths have been formulated about these common menaces — some true and some not so true. By learning some simple facts about weeds, you can put yourself in a much better position to rid your garden of these unwanted guests.

Test your knowledge with this basic weed IQ test to see if this year's gardening will be an uphill battle or a walk in the park. Are these statements true or false?

A Weed Is a Weed

False. Believe it or not, there are actually thousands of weeds. However, only about 25 to 30 are common in maintained turf, depending on where you live.

While the majority of weeds have broad leaves, some may have narrow leaves similar to blades of grass. Weeds also have varying life spans. Most common weeds are classified as annuals because they are produced from seeds and only live for a single growing season. They die soon after flowering. However, some varieties of weeds are long-lived and don't die after flowering. This group, which can reproduce by seed or by vegetative means such as rooting, are called perennials and continue to thrive as long as conditions permit.

Pulling a Weed Is the Most Effective Way to Kill It

False. While it's the most common method of weeding, manually pulling weeds does not guarantee a solution. Since perennial weeds can reproduce from rooting, even if part of a taproot lives after a weed is pulled, the plant can regenerate itself. If you do pull weeds, the only way to ensure the plant won't come back is to make certain the entire root system is removed.

A simpler solution is to eliminate the hassle of killing weeds altogether by preventing them before they even start to germinate. By using a pre-emergent herbicide, such as Preen, you can effectively prevent weeds for up to three months. Easy to apply, this herbicide may be sprinkled on the soil surface of garden beds or on top of mulch any time of the day throughout the growing season. Simply water in.

Weeds Die Naturally at the End of the season

Now here's a test to see if you've been paying attention, because the answer is both true and false, depending on the weed. The answer is true with annual weeds. They will die at the end of their season. But realize that different weeds thrive in different weather conditions, so you can still have annual weeds year-round.

In terms of perennials, the answer is false. Perennials can survive for years. In fact, seeds can live for seven years or more, waiting until conditions are right to germinate. Perennial weeds also store reserve "food" in their root systems and continue to sprout again and again, even after their tops are destroyed.

Weeds Are a Natural Part of Gardening

This is true, but that doesn't mean you have to accept it. The reality is weeds are everywhere. Their seeds are airborne, which means they can be easily carried from one yard to the next. They can be transported by humans, animals, insects, and even water. Your own trusted lawnmower could be a carrier. Weed seeds can also be unintentionally introduced through straw or hay, mulch, or even inferior grass seeds, which are not weed free.

No matter how many times you apply a weed killer, seeds are bound to be reintroduced to your garden. Here again, the only way to remain weed-free is to apply a weed preventer. That way, regardless of how or when new seeds are introduced, they'll never have a chance to germinate.

Weeds Are Ugly, but at Least They're Harmless

This is false on many fronts. First let's consider the statement "weeds are ugly." A weed is defined as a plant that is not intentionally sown. Therefore a weed can actually be somewhat attractive, just unwanted where it is.

Secondly, certain weeds, such as poison ivy, can actually cause severe skin irritation. Other weeds, including sandbur and thistle, can also scratch and irritate your skin.

Another point to consider is that, if left unchecked, weeds will deprive your flowers of needed water, light, and soil nutrients. Weeds can also produce substances that are toxic to your plants. Eventually, they will squeeze out what you actually want in your garden.

All Weed Control Products Are Essentially the Same

This statement is false. There are many different types of herbicides available. If you're not achieving the results you desire, you're likely using the wrong type of product.

First it's important to understand the difference between a pre-emergent and a post-emergent herbicide. Pre-emergent implies controlling the weed or weed seed before it "emerges" or germinates. It does not kill existing weeds. A post-emergent herbicide only works on weeds that have already begun to grow. They actually kill existing weeds, but won't prevent new ones.

Herbicides can also be selective or non-selective. Selective herbicides are those types that only kill selected or target weeds. Non-selective herbicides can kill any plant they touch without being at all selective. These require careful handling so as not to damage wanted garden plants.

Finally, some herbicides are also available as combination products. For instance, Preen 'n Green, which is endorsed by the American Rose Society, offers plant nutrition in addition to weed prevention. By combining the two, you eliminate much of the work required to keep your garden flourishing and encourage strong root development and abundant blooms.