Plants are basically found everywhere, from our lawns to city parks and even in the cracks on the sidewalk! This is a good thing, obviously, as it helps to keep our environment clean and clear. However, some of us grow plants because we love gardening and therefore have a variety of plants in our backyard, but gardening is not an easy hobby, and there are many problems that a person must face. From insects to soil fertility, the list of issues is long, as is the list of possible solutions. Even with all of our expertise, there is one problem that seems to have no end – WEEDS!
If you ever observe the greenery around you or simply look at your own lawn, you will almost certainly come across plants that seem out of place. These unwanted plants that you may have noticed are ‘weeds’. Yes, a ‘weed’ is not a specific plant, but rather the term used by humans to describe plants that are ‘growing in the wrong place’.
Why are weeds so persistent?
Weeds can grow in almost any environment on Earth, ranging from favorable places (e.g., farms, nurseries and gardens) to unfavorable ones (e.g., structures like pillars and walls). Their growth is a problem for farmers/gardeners, as weeds use up a lot of nutrients in the soil and affect the plants growing around them. It also affects the quality of harvested crops. To make matters worse, some weeds produce toxic substances that not only have an effect on surrounding plants, but can also affect the soil quality.
One of the major factors behind the high growth rate of weeds is abundant seed production and their high rate of survival. Weeds develop according to the environment in which they are being dispersed (for example – by air, water or fruits). Certain weeds also have the advantage of vegetative reproduction, which allows them to grow an entirely new plant from only a fragment of the parent plant, the only similarity being their genetic makeup. Some weeds even have the ability to hybridize.
In the case of hybridization, the crossing takes place between two genetically different plants. The third plant (the one being created) has a different set of traits, which helps the species achieve genetic variability. Such variability can lead to the development of mechanisms to protect themselves from control measures, such as herbicides.
Many weeds adjust to their environment, which helps them not just spread, but also survive. Some of the types develop waxy layers on their leaves to act as a defense mechanism. This helps them stay protected against any chemical treatment and doesn’t let chemicals penetrate into the leaves or stems. These stubborn plants even grow in areas that have relatively infertile soil. Many of these unwanted plants also develop foul odors and tastes that prevent the animals from consuming them. The ability to produce toxic material also helps the cause of keeping animals at bay.
Now, you may be thinking, ‘Why can’t I simply apply herbicides and be done with them?’ Well, that probably isn’t the best of ideas, as the weeds could be ‘biologically similar’ to the nearby plants. In such a situation, the herbicide will end up destroying the weeds along with your plants. Even after applying herbicides, the seeds that have already been dispersed by the weeds have a very good chance of germinating. Thus, the overall effect of applying herbicides would be worse on the real plants than on the weeds!
You could cut these weeds in half, apply poisonous chemicals and prohibit any nutrition, but they would still happily keep growing. With all of this in mind, it is clear that weeds are a long-lasting group of plants that are highly competitive and show no signs of disappearing.
- Cal State Monterey Bay
- Pennsylvania State University
- Iowa State University Department of Agronomy
- Biology LibreTexts