What are weeds?

What are weeds?
(Image credit: Getty Images)

Weeds! The bane of every gardener! They pop up where and when you don’t want them to, spilling your careful planting plans and strangling the plants you carefully nurture. But what are weeds? 

Here we will explain what defines a weed, as well as some of the most common weeds that gardeners will encounter in North America. There’s a number of different kinds of weeds, including annuals and perennials, and there are also countless ways to get rid of them. We will also touch on how you can get rid of them - if you are looking for a natural remedy, read how you can use vinegar as a weed killer. Another way, especially if you are keen not to use chemicals, is to invest in one of the best electric weed eaters.

What the expert says…

Chuck Smith says that they generally "argue against weed killers and chemicals as they often do more harm than good and if you regularly maintain your garden and keep on top of weeds, it should be easily manageable.’’

Chuck Smith, owner of garden and maintenance company Alpha Zeta in Palm City, Florida, says: “Weeds are basically just wild plants, plants growing where they are unwanted. Common examples are things like dandelions, crabgrass and ground ivy. 

"They aren’t necessarily bad in all cases but it’s recommended you remove them as early as possible as a lot of varieties can be invasive and overwhelm your garden if given the chance. A key tip for this is to clean your tools after weeding a section of your garden. This removes the chance of you dragging any seeds across the garden with you and allowing the weed to spread."

So if weeds are stopping your lawn from looking lush, popping up in your planters or the bane of your borders, read on to find out more about what you are up against…

What are weeds?

According to Richard Mabey, author of Weeds: How Vagabond Plants Gatecrashed Civilisation and Changed the Way We Think About Nature, “Weeds are not only plants in the wrong place, but plants which have slipped into the wrong culture.”

It’s true - some weeds can be very pretty - the yellow flowers of dandelions and the fluffy purple pom poms of Canada thistle can look rather attractive - and they can also attract beneficial wildlife and pollinators. But in a managed garden or yard they can too quickly take over, and strangle and suffocate your carefully nurtured plants. You might want to encourage a ‘wild’ area in a garden to encourage pollinators, and here wildflowers and weeds might be left to flourish.

Jen Stark, founder of Happy DIY Home, adds: “Weeds are plants that grow in places they're not supposed to. They can be annuals, biennials, or perennials and can be common in yards or gardens. They typically grow fast and have the ability to reproduce quickly.’’

She describes the different types of weed you are likely to encounter below:


These weeds only live for one season. They germinate, grow quickly, and produce seeds before dying in the wintertime. Crabgrass, dandelion, purslane, and lamb's quarters are examples of typical annual weeds.


These weeds live for two years before dying off in the second year after germination. Burdock, chicory, charlock mustard, and wild lettuce are common biennial weeds.


These weeds live longer than two years before dying off at the end of their lifecycle. Some perennial weeds can live for decades! Common perennial weeds include bindweed (also known as morning glory), Canada thistle (or musk thistle), and horsetail (or Equisetum arvense).

Why would you want to get rid of weeds?

Anyone who has spent hours digging up weeds or battling against them with chemical or natural methods might start to wonder if it is worth all the effort. Perhaps you should just leave them to get on with it? But weeds can have a detrimental effect on your garden.

Natural weed killer

(Image credit: Getty Images)

The problem with weeds (and why they are so successful) is that they grow quickly, and often have deep root systems. This means your lovely cultivated plants are constantly in competition with them - fighting for nutrients from the soil, light and water.

They can also provide the ideal hiding spot for other nasties that are after your garden plants - such as snails and slugs.

For vegetable growers, letting weeds grow among your neat rows can also be an issue - let them take over and you could be in danger of pulling up your precious crops while you’re pulling up the weeds! They also offer the ideal spot for pests to thrive and feast on your delicious vegetables.

You can even be leaving your crops open to disease - shepherd's purse, for instance, is a member of the brassica family and can leave your brassica crops - such as cabbages and broccoli - open to contracting club foot disease.

Another little-known issue is that some weeds create an area around them that is infertile (known an alleopathy) - so if you have weeds such as pigweed, thistle or lambs’ quarter around your crop you may find your plants don’t grow, or that seeds won’t germinate.

So it’s clear that as well as being not so pretty to look at, weeds can be harmful to your growing plans.

Jen Stark says: “There’s a number of ways to get rid of weeds in your garden and yard. You can either dig them up from the ground by hand or with a tool such as a hoe or shovel. There are also chemical herbicides that may be sprayed directly onto the weed to eradicate it entirely. 

However, these chemicals can be dangerous if consumed by humans or animals, so use caution when using these items around kids or animals. Utilizing an organic herbicide, such as vinegar and water sprayed directly onto the plant's leaves and stems until the plant totally withers away, is another method for eliminating weeds (this will take longer than using chemical herbicides)."

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Naomi MacKay

Naomi MacKay has been a freelance writer and editor for the past 20 years. She previously made the move from local newspapers and consumer technology magazines into the gardening press as Assistant Editor at Garden Answers magazine, and has also worked for the Royal Horticultural Society, and writes garden columns for a number of publications.

With contributions from