But regardless of the type of weed, one of the easiest and most effective way to keep weeds away is simply to keep a thick and healthy lawn.

Thick and healthy lawns require:

• annual overseeding
• seasonal fertilizing
• proper watering amounts
• cutting grass regularly at the right height
• using a mower with sharp blades

Related Post:  How Often Should  You Mow Your Lawn?

Keeping a thick lawn means that only a few weeds will be able to invade your grass.

And if the odd one should pop up, you can simply pull it out to prevent further spreading of the root system

1. Crabgrass

​This is an annual weed reproducing by seed. It has branching, spreading stems.

Its coarse, blue-green to purplish leaf blades can be smooth or hairy, depending on the species.

Both varieties have tapered leaf blades. The base of the clump has several fingerlike spikes rising from narrow stems.

Keeping your lawn thick and healthy, as well as free of bare spots, is the best way to prevent crabgrass​.

​

2. Dandelion

Well, I think almost everyone knows what this weed looks like!

It's a perennial which is part of the Aster family. It is well known for the bright-yellow flowers and large leaves rising from a long, deeply penetrating taproot.

They reproduce by producing a round, white, globe shaped seed head. Dandelion favour thin turf and will flower from early Spring until late Fall.

You can make a simple home-made weed killer to treat them.

Mix 1 gallon of white vinegar + 1/4 cup salt +1/2 liquid dish soap. Pour the mixture into a spray bottle. Do your best to only spray the dandelion so as not to kill grass or plants nearby. The dandelion should wilt by the next day. 

3. White Clover

This is a perennial that used to be part of grass seed mixes.

Also called White Dutch Clover it's leaves are distinguished by three lobes with a crescent-shaped white band.

It spreads by creeping stems and does well in sparse, undernourished turf with too much moisture.

Control it by feeding your lawn nitrogen fertilizer and avoiding excessive applications of phosphorus.

4. Ground Ivy

This weed is also commonly known as Creeping Charlie.

It's part of the broadleaf perennial variety and fall in with the mint family.

It features square stems with bright green, rounded scalloped edged leaves.

This weed reproduces by seed as well as having creeping stems that root as they touch the ground.

5. Yellow Wood Sorrel

Also known as Sour Clover and Oxalis.

This is a broadleaf perennial, even though it might act as an annual in some regions.

It shows clover shaped leaves and yellow flowers - each with five uniformly shaped petals.

This plant spreads by roots and seed.

6. Quackgrass

This weed will often be mistaken for Crabgrass.

It's a perennial with flat light-green to blue-green leaves which are flat and nearly smooth on top. The under part of the leaf sheaths are hairy.

At the top you will find spikelets alternating from one side of the central stalk to the other.

Each spikelet is made up of 3 to 7 florets. It spreads by seeds and aggressive rhizomes (underground stems).

7. Yellow Nutsedge

This is also known as Nut Grass and Ground Almond.

It's a grassy perennial sedge with triangular stems and numerous slender leaves near the base of the plant.  However, it is sparse near the top except for a cluster at the base of the an umbrella-like cluster of yellowish spikelets.

Preventing this weed from establishing itself is the best plan.

This weed reproduces by seed, tubers and rhizomes that grow at the root tips. Tubers often persist in the soil, making established plants difficult to control.

8. Spotted Spurge

This weed likes to grow close to the ground.

It is an annual which reproduces by seed and it will create a fast-spreading mat along the ground.

The leaves are rounded, small and green with a reddish brown or purplish spot on top. When the stems are cut they exude a milky liquid.

Want to Know More About Weeds in Ontario?​

To see the full gallery of weeds commonly found in Ontario, visit the Ontario Provincial Government site here.

There are hundreds more there to help you identify the weeds popping up around your property!

If you have a lawn with a lot of weeds, you should get your grass professionally treated, and begin a protocol of overseeding and fertilizing.

For professional weed treatment, including organic options, we recommend that you contact Green Blade Lawn Care Services if you reside in Oakville, Ontario or within Halton region.