Different types of weeds grow in a hurry, competing with the grass you sow in your lawn. 

They weaken desirable plants in less time and make your lawn susceptible to various problems, such as insect infestation, weather stress, and disease.

If you don’t want weeds to take over your green oasis and make it dead and dying, you need to know about the common weeds in Ontario gardens.

This blog discusses types of weeds with names and the effective way to get rid of them to preserve the overall health of your lawn.

Related Blog: Say Goodbye to Weeds: Tips for Successful Weed Control

What Are Lawn Weeds?

An infographic explaining the types of weeds

Weeds are a nuisance, but some must be removed to prevent them from outgrowing native plants, flowers, and food crops.

A plant that harms the environment and is unwelcome in the area where it grows. A classic example is crabgrass. It is one of the types of lawn weeds that look beautifully green in the beginning and trick you into thinking that it is okay to let it grow. 

If you don’t get rid of it, it slowly smothers your turfgrass and grows aggressively on the sidewalks, making your lawn look horrible.

Types can be categorized by the following:

Noxious Weeds 

Any plant that federal, state, or local government officials have declared harmful to the public’s health, agriculture, recreation, wildlife, or property is considered a noxious weed. 

Examples: Purple Loosestrife and Field Bindweed.

Invasive Weed

Because these non-native invaders have no natural enemies or competitors to slow their growth, they are able to supplant native plants, wipe out species, and change ecosystems. 

Examples: Parsnip and Yellow Iris.

Beneficial Weeds

Some types of weeds aren’t always undesirable. Numerous weeds contribute organic matter and stabilize the soil. Some are edible and provide wildlife habitat and food as well. 

Additionally, weeds indicate the health of your lawn, too.

10 Common Weeds in Ontario Gardens

A circular diagram listing the common weeds in Ontario gardens

These are the common weeds in Ontario gardens:

1. Canada Thistle 

Canada Thistle is a seed-bearing perennial plant. These are the types of weeds that spread exponentially in your lawn. The plant has spiky purple blooms that identify it as a weed.

The leaves are lobed and shaped like an arrow. The plant appears extremely hairy and has a spiky stalk. They resemble the seed heads of dandelions.

Canada Thistle typically grows in open spaces to promote the growth of other weeds. 

These types of weeds can also be found in gardens, roadsides, riverbanks, and forest openings.

Controlling These Types of Weeds 

Preventing infestation can be achieved by mowing it into the soil before planting. 

If you’re working in a limited area, you can also use a pair of scissors to cut off the weed at the base. This weed can snap in half and sprout. 

Thus, uprooting it will not control it. Even a small amount of the deep-rooted soil can help the plant grow again.

To completely avoid further infestation, it is usually preferable to plant in regions where this particular weed variety has already caused issues.

Canada thistle plants can be treated with glyphosate at any point during the bud stage. 

Using a herbicide with a glyphosate concentration of 40% or more is recommended, combined with a 2% product spray solution.

2. Dandelions

The deep taproot may reach a length of 15 feet, and the puffball seed head, which scatters seeds with every wind, is the bane of dandelions. 

The best defence against dandelions is to grow thick, healthy grass in the lawn through proper fertilization and a high mow height. 

These types of weeds commonly appear in the most unexpected places when planting beds and walks, such as hidden in the edge row of pavers or rooted in the middle of a perennial clump. 

Getting Rid of Dandelions 

Apply a mist or excavate them. Kick dandelions a little bit before spraying to scruff and wind the leaves.

It facilitates better spray penetration. Digging should provide at least 2 inches of taproot; otherwise, they will regrow as two separate plants.

3. Japanese Knotweed

Large green leaves on thin stalks of Japanese knotweed growing close to gravel.

Its attractiveness is actually only bearable during the blooming season; after the growing season ends, it leaves behind a patch of dried canes that blight any landscape, often reaching heights of six feet. 

Through rhizomes, these types of weeds spread aggressively on your lawn.

Getting Rid Of Japanese Knotweed 

Hand-pulling these types of weeds is not a good option, as they can regenerate from tiny pieces of roots left in the soil. The best way to stop it from growing is using a weed killer.

4. Chickweed 

Low-growing chickweed is a winter weed that can damage crops early in the growing season if it establishes itself in cool conditions. 

The Common Chickweed and Sticky Chickweed are the two species of these types of weed. Additionally, these weeds frequently cause issues for turf and landscape grasses.

When soil temperatures rise to 40 to 50 degrees Fahrenheit, chickweed begins to germinate.

If the soil temperatures rise to 60 degrees Fahrenheit, growth becomes more sluggish. It grows best in conditions with low fertility and damp soils.

Chickweed’s ability to spread makes it extremely difficult to eradicate. 

Eliminate These Types of Weeds

The easiest way to manage it is to pull the weeds by hand when they’re still small or cultivate them and then mulch the area once they die. 

These types of weeds affect tomatoes and other valuable crops, so get rid of them from your garden.

5. Clovers 

The trifoliate leaves of clover plants make them clearly identifiable as perennial types of weeds. 

They produce white or pink blooms when they flower in late summer and early fall.

Clovers expand swiftly and favour places with little vegetation, like farmed fields or deserted farmlands. 

They grow in soil deficient in nitrogen and creep along the earth. If you find this weed on your lawn, the soil may not have received enough nitrogen.

Ways of Elimination 

Prevention is key to eradicating these kinds of weeds since, once established, they are difficult to eradicate. 

For successful eradication, fertilize your lawn. As an alternative, remove the entire plant by hand.

6. Lamb’s Quarter 

An annual non-woody plant called lamb’s quarters often grows in disturbed places like gardens, mulch piles, and empty lots. 

A few branches may erupt from the single stem above the base. Leaf stems and stalks might have stripes or a reddish or purplish tint.

How To Manage These Types of Weeds

These types of weeds have shallow roots, making them simple to pull out with a hand or hoe. 

Just make sure to get them before blossoms start to lay seed, ideally as early as possible. 

Liquid herbicides can be sprayed on specific areas of lambs’ quarters plants or destroyed with a flame weeder.

7. Nutsedge

These are perennial types of weeds that grow in sun or shaded garden areas.

Nutsedge’s appearance consists of little, nut-like tubers on the root system, triangular stems, and thin, grassy leaves. 

These weeds are easy to identify when they appear in lawns because they frequently grow more quickly than turf grass.

How to Control Nutsedge Growth

To help prevent nutsedge, mulch garden areas in the spring. Although plants are simple to pull up by hand, an infestation will require several weedings to eradicate. 

8. Giant Ragweed

These types of weeds have deep roots and branches, and their propensity to grow up to 15 feet tall makes them easy to detect. 

Similar to its cousin, the big ragweed, but not like goldenrod, it generates copious amounts of pollen, which triggers severe allergies.

Controlling these Types of Weeds 

Wind can spread the 5,000+ seeds that giant ragweed plants can yield per plant. Its seeds have a ten-year shelf life in the ground. This plant destroys crops.

You need to keep lawns healthy to ward off ragweed. Robust grasses can resist giant ragweed. Tilling a seedling’s stands is another way to mess with its life cycle. 

If you need herbicide, apply atrazine, a pre-emergent herbicide, in the spring.

9. Ground Ivy

These weeds look a lot like clover. Ground ivy, the ubiquitous lawn weed, has various names. 

It goes by several names, such as gill, gill-over-the-ground, and creeping Charlie.

Ground ivy has lovely blossoms despite being considered a weed, and it smells good when mowed. Additionally, it is utilized as a medicinal herb.

Ways to Eradicate these Types of Weeds

To get rid of this weed, dig and pull in a small area. However, since leftover stems or roots can continue to grow and spread, this method may not be entirely effective. 

Persistence is key to eradication success. But you can also count on broadleaf herbicides, sprayed once in late September and once again in a month.

10. Broadleaf Plantain

The broadleaf plantain forms a cluster of leaves with parallel veining. If untrimmed, the leaves of these types of weeds can grow up to six inches long and three to four inches across on long, broad petioles. 

They are minute, glossy, and dark brown and spaced throughout the length of the flower stalk.

The foliage can be wavy, blue-green, and frequently waxy. The taproot is short and fleshy, from which the fibrous roots grow. 

On long, leafless flower stalks that emerge from the rosette, insignificant blooms are formed. 

The seeds develop into tiny capsules.

Plantains can take over a lawn due to their propensity for spreading by seed, resilience to harsh winters, and annual growth.

The problem with plantain is that removing only a portion of the root system can regrow the remaining root pieces. 

How to Control The Growth

Despite having shallow roots, the plants are easy to remove from a lawn. 

If digging isn’t feasible or effective, broadleaf herbicides designed for lawn use will easily eradicate plantains. 

Weed-killers eliminate most broadleaf weeds without damaging grass.


What are invasive weeds?

Non-native plants that spread quickly and potentially harm the environment are known as invasive weeds. Water hyacinth, kudzu, and Japanese knotweed are a few examples.

How can I distinguish between several types of weeds?

Weeds can be distinguished by their growth pattern, leaf form, flower structure, and root system. Identification can be aided by a plethora of applications, gardening books, and internet tools.

What are the common weeds in biennial Ontario gardens?

Biennial weeds’ life cycles take two years to complete. In the first year, they grow leaves, stalks, and roots, and then they flower, make seeds, and eventually die in the second year. Garlic mustard, wild carrot, and thistle are a few examples.

What are common perennial weeds in Ontario gardens?

Weeds that are perennials live longer than two years. Both seeds and vegetative structures like roots, tubers, and rhizomes can be used for their reproduction. Quackgrass, clover, and dandelions are a few examples.

Is there a specific number for the types of weeds?

There are many different types of weeds, and the number of them varies based on the area and the particular classification standards applied. In general, weeds can be classified according to their growth form (grass, sedge, or broadleaf), life cycle (annual, biennial, or perennial), and ecological impact. 

Wrapping It Up

These are the types of weeds with names that can become an eyesore in your lawn if you don’t get rid of them in time.

The first step is to identify common weeds in Ontario gardens. After that, you can dig or pull them manually or use a post-emergent product to eliminate them.

Using the right technique and product at the right time requires knowledge and experience. If you want help with it, contact Falcons Landscaping.

From planting ornamental grasses in your lawn to providing various landscaping solutions, we take care of all your lawn care needs.