If you have a garden, you may have noticed that along with your plants, there are some smaller plants growing where they shouldn’t! These unwanted plants are what we call weeds. According to the Merriam-Webster dictionary, a weed is defined as “any plant that is not valued where it is growing; especially one that tends to overgrow or choke out more desirable plants.” Weeds are known for growing at an exceptionally fast rate, which is why we use the phrase “growing like a weed” to describe something that had a growth spurt!
Why don’t we want weeds in our gardens?
Weeds tend to be unattractive, and they draw attention away from some of the more beautiful flowers in we desire in our gardens. This is the first explanation for why we want to pull the weeds from the ground or spray them with weed-killer. However, the most important reason to get rid of weeds is because they often use up all of the nutrients that the other plants need to survive.
Why don’t we want weeds in our gardens?
Weeds tend to be unattractive, and they draw attention away from some of the more beautiful flowers in we desire in our gardens. This is the first explanation for why we want to pull the weeds from the ground or spray them with weed-killer. However, the most important reason to get rid of weeds is because they often use up all of the nutrients that the other plants need to survive.
A weed in a garden sometimes seems to pop up out of nowhere, but the reality is that those seeds are often already in the soil you’ve planted your garden in. If the seeds aren’t already in the soil, they’re often dropped by birds or have blown into your plants from another nearby weed. One of the most prevalent type of weed is the Canada thistle (Cirsium arvense).
Many species of finches favor the thistle seed over any other type of wild seed because it’s packed with protein and oils. Sometimes, the birds pick up too many seeds than they can carry, and the seeds that fall often end up growing into the large, spiky weed that takes over many gardens. Another easily identified weed is the dandelion (Taraxacum). These yellow wildflowers like to spread out across large expanses of grass, such as a backyard lawn. After a few days as a flower, the head of the plant closes and allows the seeds to mature. Gradually, the yellow petals are pushed out to make way for the fluffy heads of the seeds that blow away in the wind to populate another area.
Unfortunately, often weeds are much better at absorbing nutrients (such as water and fertilizer), and thus outcompeting the intended plants. If all of the nutrients in the soil are used up by the weeds, there’s not enough left to keep your plants healthy, or even alive at all. To complicate things further, these weeds will grow larger and larger until they completely overshadow your beautiful flowers or vegetables! When rays of sun can no longer reach the plant’s leaves, the poor plant can’t use the sun’s energy to make its own nutrients, causing it to wither away. Eventually, most (if not all) of your plants will die unless the troublesome weeds are taken care of.
How do we get rid of weeds?
In a perfect world, we would be able to pull weeds with little to no effort on our part. But after years and years of constantly being pulled out of the ground, many weeds have evolved to be more hardy and fit for survival.
How do we get rid of weeds?
In a perfect world, we would be able to pull weeds with little to no effort on our part. But after years and years of constantly being pulled out of the ground, many weeds have evolved to be more hardy and fit for survival.
In the picture above, you can see the roots of a Canadian thistle plant after two years of growth. It would be almost impossible to pull the entire plant out of the ground because most of the roots are intertwined. Other species of plants have adapted to being pulled straight up from the ground by evolving a corkscrew-like root. Having an uneven edge to the root makes it extremely difficult to extract the entire plant, instead of just plucking the leaves off.
It’s important to pull the whole root of the plant out because many of these weeds are creepers, which means they spread by extending their roots. Most of the time, creeping weeds also spread through seed, so it’s especially difficult to entirely get rid of them. In such a case, selective herbicides are the easiest solution, many of which target enzymes within specific plant cells. Enzyme activity in plants normally occurs in a controlled state of equilibrium, but when a herbicide targets an enzyme site it disrupts the sequence of complex chemical reactions. This disruption produces highly toxic compounds in the plant, poisoning and killing the weed.
Can you grow weeds unintentionally?
Here’s an interesting activity to try out at home, and it doesn’t require any special materials to make it work. All you’ll need is a few containers, water, and about a handful of two to four types of soil. If you have a garden, dig up a little bit of soil without getting in the way of any of your growing plants. Place this soil inside a container one might use to plant a small flower in. Repeat the process with soil from a few other locations; the side of a road and a home and garden shop are good places to start!
Once you have your containers of soil, place them in a window or similar area where they can get plenty of sun. Start watering your soil as you would if you’d planted a seed or flower in it. Within a few days or weeks, you might see a plant growing even though you never planted anything! This shows how weeds can grow without having to be planted because their seeds are often already in the soil. You can either discard your soil, or keep taking care of the plant to see what it looks like when it matures! If any of the soil types grew no plants at all, this means the soil has no weed seeds present, and would make a great choice to plant a flower or vegetable garden in the future!
References:
https://www.merriam-webster.com/dictionary/weed
Image Credits:
Schmidt, Andrew. “Weeds With Blooms”. Released into the public domain. Uploaded on 7/28/17 from publicdomainpictures.net
“European Goldfinch”. Released into the public domain. Uploaded on 7/28/17 from commons.wikimedia.org
Hume, Greg. “Dandelion Flower”. Released into the public domain. Uploaded on 7/28/17 from commons.wikimedia.org
Ross, Merrill. “Two Years Underground Growth of Canada Thistle”. Released into the public domain. Uploaded on 7/28/17 from the Department of Botany and Plant Pathology at Purdue University
It’s important to pull the whole root of the plant out because many of these weeds are creepers, which means they spread by extending their roots. Most of the time, creeping weeds also spread through seed, so it’s especially difficult to entirely get rid of them. In such a case, selective herbicides are the easiest solution, many of which target enzymes within specific plant cells. Enzyme activity in plants normally occurs in a controlled state of equilibrium, but when a herbicide targets an enzyme site it disrupts the sequence of complex chemical reactions. This disruption produces highly toxic compounds in the plant, poisoning and killing the weed.
Can you grow weeds unintentionally?
Here’s an interesting activity to try out at home, and it doesn’t require any special materials to make it work. All you’ll need is a few containers, water, and about a handful of two to four types of soil. If you have a garden, dig up a little bit of soil without getting in the way of any of your growing plants. Place this soil inside a container one might use to plant a small flower in. Repeat the process with soil from a few other locations; the side of a road and a home and garden shop are good places to start!
Once you have your containers of soil, place them in a window or similar area where they can get plenty of sun. Start watering your soil as you would if you’d planted a seed or flower in it. Within a few days or weeks, you might see a plant growing even though you never planted anything! This shows how weeds can grow without having to be planted because their seeds are often already in the soil. You can either discard your soil, or keep taking care of the plant to see what it looks like when it matures! If any of the soil types grew no plants at all, this means the soil has no weed seeds present, and would make a great choice to plant a flower or vegetable garden in the future!
References:
https://www.merriam-webster.com/dictionary/weed
Image Credits:
Schmidt, Andrew. “Weeds With Blooms”. Released into the public domain. Uploaded on 7/28/17 from publicdomainpictures.net
“European Goldfinch”. Released into the public domain. Uploaded on 7/28/17 from commons.wikimedia.org
Hume, Greg. “Dandelion Flower”. Released into the public domain. Uploaded on 7/28/17 from commons.wikimedia.org
Ross, Merrill. “Two Years Underground Growth of Canada Thistle”. Released into the public domain. Uploaded on 7/28/17 from the Department of Botany and Plant Pathology at Purdue University
