Landscaping and lawn care in Thornhill

Thornhill has been split down Yonge Street since it was settled in 1794. Before 1971 the Township of Markham ran the east half and the Township of Vaughan the west half. Today it’s the City of Markham and the City of Vaughan, both in York Region, Ontario.

For landscaping and lawn care, that split decides which by-laws apply. Two houses a few hundred metres apart can have different watering hours, a different grace period for new sod and a different leaf pickup schedule. People usually draw Thornhill’s edges at Dufferin St to the west, Highway 7 to the north, Highway 404 to the east and Steeles Ave to the south, where Toronto starts.

Which side of Yonge are you on?

East of Yonge is Markham and west of Yonge is Vaughan. Postal codes are a quick check: L3T is the Markham side and L4J the Vaughan side. If you’re not sure, your property tax bill names the city.

Scroll sideways to see the whole table.

Watering rules are from York Region’s summary of each city’s by-law. The rest comes from each city’s own pages, listed under Sources. The cities’ pages are the final word, so check them before you plan around a date.

How long can you water new sod in Thornhill?

York Region lists a two-month grace period for new sod and seed on the Markham side and one month on the Vaughan side. New sod needs far more water in its first few weeks than an established lawn, and that’s what the grace period is for.

In practice, a Vaughan-side lawn laid in early summer goes back on the normal schedule sooner, while it’s still rooting. The trade-off is that Vaughan’s normal schedule allows both the morning and the evening window, where Markham allows only one.

Sod laid in late August or September has an easier time on either side than sod laid in July. Penn State Extension notes that sod laid in summer needs more frequent watering and takes longer to establish. Our guides on the best time to lay sod in Ontario and how often to water new sod go into the details. The sod installation page covers the job itself.

Do you need a permit to remove a tree in Thornhill?

Yes, if it’s a private tree with a trunk 20 cm (about 8 inches) or more across, on either side of Yonge. Markham measures the trunk 1.37 m above the ground. Vaughan asks you to confirm the tree’s size and ownership and, for most permit types, get an arborist’s report before you apply.

Vaughan also has a separate permit for removing or injuring a tree because of work on a residential property, such as changing a driveway or walkway. Both cities count injuring a tree, not only cutting it down. Digging a new garden bed or relaying a patio over the roots of a big maple can fall under that, so ask the City first if the work is close to a large tree.

South of Steeles, in Toronto, the private tree threshold is 30 cm. Our North York page covers Toronto’s rules.

When is leaf and yard waste pickup in Thornhill?

On the Markham side, pickup runs every other week from April 7 to October 30 in 2026. Material goes in kraft paper bags or open rigid containers, each under 18 kg. Branches under 15 cm across go in tied bundles under 1.2 m long. Grass clippings aren’t collected.

Vaughan collects weekly from late April and again in the fall, and every other week through the summer (from the week of June 9 in 2026). In 2025 its last fall pickup was in early December, well after Markham’s ends. Vaughan takes kraft paper bags, or open-top rigid containers up to 121 litres marked for leaf and yard waste, at the curb by 7 a.m. The City mails out yard waste stickers on request. Neither city takes plastic bags, and Vaughan’s waste calendar has this year’s exact weeks.

That difference changes how you time a fall cleanup. On the Markham side, the bags need to go out on your last pickup day before October 30. Our fall cleanup checklist has the rest.

How high can a fence be in Thornhill?

On the Markham side, a fence can be 1.2 m (4 feet) in the front yard and 1.8 m (6 feet) along the side and rear property lines. On a corner lot, the street side is held to 1.2 m.

On the Vaughan side, a front yard fence within 2.4 m of the street can be 1.2 m high, and most other residential fences can be 2.0 m. Vaughan’s by-law counts a hedge that acts as a fence, so a hedge in that strip of front yard is held to 1.2 m too, which matters when you book hedge trimming. The by-law has more cases, such as fences next to a driveway or a public walkway, so check its table before you replace a fence.

Repainting or repairing an existing fence doesn’t change its height. Fence painting and staining and deck and fence repair don’t run into these limits. Our guide on fence height rules in Markham and Toronto has more.

Heritage rules in old Thornhill

Both halves of the old village are heritage conservation districts. The Markham half is one of four in Markham, along with Unionville, Markham Village and Buttonville. There, the City lists new or changed driveways, front walkways, front yard patios, new or different fences and painting as work that needs a heritage permit. Planting, general repairs (fences included) and back yard patios that can’t be seen from the street don’t.

The Vaughan half is one of Vaughan’s four districts, along with Kleinburg-Nashville, Maple and Woodbridge. Vaughan asks for a heritage permit for any work that changes how a property looks.

If you want to change the front of a property in the old village, talk to your city’s heritage staff before booking anything. Interlock repair that relays the same pavers in the same layout is a much smaller change than a new driveway design, but it’s still worth a quick call to check.

Landscaping quotes in Thornhill

We’re based in Markham and work on both sides of Yonge, from lawn care and sod to interlock and deck work. Put your postal code in the message: L3T or L4J tells us straight away which city’s watering, tree and pickup rules the job runs under. Text it with a couple of photos to (437) 684-2535, or use the form below, and we’ll arrange a free visit. Further out, see our pages for Markham, Vaughan and Richmond Hill.