I live in North York and I have noticed new type of grass of weed that did not exist before in my garden. It is also present in many other gardens in the neighborhood. Patches are now of the order a meter or more, but are increasing in size and new plants are starting to form new patches. It looks very much as ordinary grass, but with wider blades, and much stronger root. It grows faster than the regular grass and is visible since it has larger number of dry leaves, especially in winter. I was unable to find such a weed on Internet. Is that some native grass, or an invasive species? Thank you very much
The most common grass invaders into lawns here in Ontario are Crabgrass, Quackgrass and Yellow Nut Sedge. These can arrive in your lawn and spread rapidly if left unchecked. The main form of transmission is seed brought in by birds or other animals and if these grasses are rampant in your neighborhood, then you will need to be extra vigilant in digging patches out, topdressing the bare spots and over-seeding with viable lawn seed. Here is an article from our library on how to keep a healthy lawn. https://www.torontomastergardeners.ca/askagardener/repairing-a-poorly-planted-lawn/
It is very difficult to make a positive Identification from your photo so I am attaching a link to a great weed ID website from the Ontario Ministry of Agriculture, Food and Rural Affairs – see below. Click on the thumbnail pictures of the above mentioned species and you will get a descriptor which you can compare with the plants in your lawn (Sedge is on page 1. and the Grasses are on page 4.).
Hope this helps.