What Are Weeds & Where Do They Come From

Where Weeds Come From

Anyone with a backyard, lawn or garden is no stranger to weeds. They are opportunistic plants that will grow anywhere that the environment suits them. Weeds also have the ability to grow quickly and spread far.

If you have had your battles with weeds in the past, you are probably wondering where do these weeds even come from?

There are many types of weeds, and they are everywhere. In my experience, I have learned that understanding weeds and where they come from is the best defense against them.

Weeds do not give up so it is a continuous battle but armed with the right information, you can keep your lawn and garden weed-free.

What Are Weeds

Weeds are defined as plants that grow in a place where they are not wanted. Usually, weeds that grow in lawns and gardens are undesirable and are removed. Weeds are plants that are undesired because they:

  • Compete with the desired plants for the resources
  • Serve as hosts for plant pathogens
  • Provide food or shelter for animal pests
  • Irritate the skin or digestive tracts of people or animals

Weeds interfere with growth of other plants and flowers because they compete for soil nutrients, land, and water. For flower or vegetable gardens, weeds can interfere with productivity and can diminish crops.

Weeds also interfere with the cosmetic appearance of a lawn as well as recreational goals such as play and sports like golf.

Where Do Weeds Come From

Weeds come from different sources. The origination of weeds is unknown, but they are found all over the world as a result of being spread through human migration and commerce. Weeds are adaptable and grow when conditions are favorable, such as specific temperatures, moisture levels, and thin grass areas. Weed seeds are a nuisance because they can spread rapidly.

Weeds are characterized as opportunistic. This means they take advantage of certain situations to grow, usually at the expense of other plants.

Weeds grow when conditions are favorable to them which includes:

  • Specific temperatures
  • Lawn moisture levels
  • Thin areas of turf
  • Cracks in pavement or roads

Weeds will grow wherever there is room for them. Weed seeds are abundant and can appear in your yard from a number of sources and some even have the ability to land in your soil, stay dormant, and emerge and spread later.

When weeds are in a growing cycle, each plant can produce thousands of seeds, allowing for vast dispersal and spreading.

If weed seeds make their way to our yard, they will take advantage of any disturbed environment where the soil has been damaged. There are multiple types of weeds and the weeds that will grow in any given area will depend on the disturbances caused and habitat.

Different Types Of Weeds

Every lawn, field, or landscape has the potential to grow weeds and there are many species of weed. Weeds fall into three main types as below:

Annual Weeds

These spread by setting seed, germinating and growing for one season. These then die off at the end of the season that marks the end of their lifecycle.

The most common species of weeds within this category include hairy bittercress, chickweed, and groundsel.

Biennial Weeds

These weeds have a two-year life cycle as opposed to the seasonal weeds. Their first year consists of germination and producing a leafy plant. The second year, these weeds flower which produce seeds to start a new lifecycle.

Common biennial weeds include clover, wild carrot and prickly lettuce.

Perennial Weeds

These weeds grow for multiple seasons and can spread via different methods including setting seed and through their root system.

Perennial weeds include ground ivy, dandelion, and thistle.

Where Did Weeds Originate From

The actual evolution of weeds is unknown, but research has found that weeds appeared in conjunction with agriculture and farming. It is believed that weeds started to show up almost 12,000 years ago and have been rapidly evolving ever since.

They take advantage of any human disturbed area and take over the habitat there. The introduction of different types of weeds to continents was thought to be part of human immigration.

As people moved and transported goods and agriculture, weeds moved around the world too. Once in a location, weeds of any type were able to take advantage of the habitat, growing and spreading quickly.

Mother Nature also helped distribute weeds across countries and continents.

How Do Weeds Grow

Weeds keep root underground, so this is where they start. The long veins within their roots will spread through the soil depending on the season and habitat that best fits with their lifecycle.

Many can also stay dormant for years until the habitat changes to one that suits their growth. Weeds are always looking for an opportunity to grow and these veins will continue to spread even if the top part of the weed is removed.

Weeds grow based on the sun exposure and the soil condition. However, they only need one of these conditions to start growing.

This means that even if you live in an area that doesn’t get a lot of sun, weeds can still take over your yard, assuming your soil is full of nutrients.

Once a weed has taken root, you need to remove the entire plant. Leaving the roots or even the stalk will not get rid of the weed.

How Do Weeds Spread

Most weed species have moved from their original growing location and out of their natural geographic ranges. Weeds have spread around the world as people migrated and commerce spread.

Weed seeds can be easily collected and transported along with harvested crops and grains, as we exchange goods around the globe.

Humans, therefore, are both a course of transport as well as a producer of the disturbed environments that weeds love to grow in.

In addition to humans, weed seeds can also spread in the following ways:


For the most part, new weeds that show up in your lawn were blown in by the wind. Dandelions are the most common weeds seen in gardens and when you think about their appearance, it is easy to see how they spread.

They look like tiny parachutes, each with a seed attached. The wind blows these apart sending the seeds in multiple directions and they can travel for great distances before landing.


Birds eat seeds and are therefore another source for seed spreading. After eating, the seeds pass through the bird’s digestive system and can then be excreted on your lawn.

Not only can this spread the seeds but as the land on the ground, they are accompanied by a natural fertilizer that lets them take root quickly.


The wind may initially blow the seeds into the street or along sidewalks, where they can get stuck in cracks. If the cracks have any soil below them, the weeds can take root and grow there.

Additionally, once it rains these seeds will be carried along and can end up in the edges of sidewalks and paths, where they take root. This is often why you will find weeds along sidewalks and driveways.


Some seeds have small barbs that can get tangled in animal fur, allowing them to get carried along. These seeds can drop into your lawn when the animal scratches itself.

Because weed seeds can remain viable for many years, it can be hard to pinpoint when they arrived at your lawn.

Getting Rid Of Weeds

Now, you know that the weeds could have come from anywhere. Some may have even been dormant in your soil before you moved into your house.

It is impossible to stop the spread of weed seeds, but this doesn’t mean you have to give up and let them take over your yard.

There are several things you can do to prevent weeds from growing in certain areas and reduce their overall presence around your home.

  • Use herbicides that disrupt the life cycles of weeds. Just make sure you use the right herbicide for the type of weed you have.
  • Hand-pick weeds as you find them. This is ideal for smaller lawns and gardens. Ideally, you want to pick the annual weeds before you plant the garden. When you do remove weeds, make sure you get the entire plant (flower, stalk, and roots).
  • Keep your lawn dense as this helps crowd out weeds.
  • Fertilize regularly
  • Water properly to create a deeper, stronger root system in the lawn, which in turn creates a healthier lawn
  • Apply lime when the pH of the soil is low to improve the availability of the nutrients in the soil making them more readily available to your plants, flowers, or vegetables.

There are also some weeds that have been characterized as noxious by the government. These are classified this way because if left uncontrolled, they can cause harm to crops, plants, and animals.

These weeds are usually foreign to the local area or imported and they are difficult to remove as the local methods are not as potent to them. In these cases, you may need to speak with a professional for removal.

Helpful Tips To Know Where Weeds Come From

Weeds are extremely opportunistic plants, and they can get in your lawn any time and from anywhere. Keeping your lawn and garden healthy is the best way to prevent weeds from growing in your lawn.

In addition to this, there are a few tips to remember with regards to where weeds come from:

  • Weed seeds can be delivered to your yard from the wind, animals, or rain
  • There are many species of weeds and not all spread in the same way
  • If the entire plant is not removed from the soil. weeds will return
  • Herbicides are cost effective and work with most types of weeds

Final Thoughts

Weeds may be plants, but they are not the pants you want in your yard. For gardeners, weeds compete with flowers and vegetables for nutrients and sun, so your plants may suffer when weeds are in the area.

Weeds in the lawn can interfere with sports, playtime, cause allergies, and can be unpleasant for bare feet. Weeds are also unattractive. Even the weeds with flowers are not aesthetically pleasing.

Knowing where weeds come from and how they spread can help you keep your lawn and garden weed-free. I recommend keeping your lawn as healthy as possible, because the stronger your lawn is, the weaker the weeds will be.

Since they are opportunistic, just don’t give them the opportunity to grow in your yard.

Drew Thomas

My name is Drew Thomas and I’m the creator of Fun In the Yard, your one stop site for all your outdoor games, sports, party activities, outdoor gear, and lawn & gardening tips.

Related Posts