Identify & Eliminate
Every Lawn Weed
in North America

It depends on the weed type. For broadleaf weeds (dandelions, clover, plantain), a post-emergent selective herbicide works within 7–14 days. In Canada, Killex is the top pick; in the US, Ortho Weed-B-Gon or similar 2,4-D products work well. For nutsedge, only a halosulfuron-based sedge herbicide will work — standard broadleaf killers have zero effect on nutsedge. For driveways and paths, a non-selective formula gives the fastest visible results in both the US and Canada.

Not always. Canada's Pest Management Regulatory Agency (PMRA) must register herbicides before they can be legally sold or used in Canada. Some widely available US products are not PMRA-registered. Additionally, some Canadian municipalities — particularly in Ontario and Quebec — have local restrictions on 2,4-D use. Our guides only recommend products you can legally buy and use in Canada. See our full Canada weed killer guide for province-specific information.

Apply pre-emergent when soil temperatures reach 50–55°F (10–13°C). US timing: Southern states (TX, FL, GA) — late January to February; Midwest and Northeast — mid-April to early May; Pacific Northwest — March to early April. Canadian timing is 4–6 weeks later than equivalent US zones: BC Lower Mainland — late March to April; Ontario and Quebec — late April to early May; Alberta and Saskatchewan — mid-May to early June. Use our free fertilizer and timing calculator for your specific region.

Yes — iron-based herbicides (FeHEDTA) are selective broadleaf killers safe for pets and children once dry. In Canada, Fiesta Turf Weed Killer is the most popular option — available at Canadian Tire and garden centres across Canada. In the US, Natria Grass & Weed Control uses a similar iron-based formula. Both kill dandelions, clover, and broadleaf weeds without harming lawn grass. See our full pet-safe weed killer guide for more options and re-entry times by product.

Because nutsedge is not a broadleaf weed — it's a sedge. Killex, Weed-B-Gon, 2,4-D, and even glyphosate all have no meaningful effect on nutsedge. The only products that work are halosulfuron-based sedge-specific herbicides — available in both the US and Canada. Nutsedge also has underground tubers (nutlets) that make it extremely resilient to a single treatment. Expect 2–3 applications across the growing season for effective control. See our nutsedge killer guide for the products that actually work in both countries.

Killex Lawn Weed Killer Concentrate is Canada's most widely used broadleaf herbicide. It controls dandelion, clover, plantain, chickweed, and 50+ other broadleaf weeds without harming lawn grass. It contains three active ingredients — 2,4-D, MCPP, and dicamba — making it effective on a wider range of weeds than single-ingredient products. Read our full Killex review and our complete Canada weed killer guide for dilution ratios, timing, and compatible grass types.

Yes — a thick healthy lawn is your best long-term defence. Mow at 3–4 inches to shade out weed seedlings, water deeply but infrequently, and overseed bare patches quickly. For active weed problems, corn gluten meal acts as a natural pre-emergent, and iron-based products (Fiesta in Canada, Natria in the US) kill broadleaf weeds without synthetic chemicals. See our organic weed killer guide for the full breakdown of chemical-free options that work in both countries.

Enter your lawn size in square feet, square metres, or acres. Select your grass type (cool-season or warm-season) and the current season. The calculator instantly shows how much nitrogen and fertilizer you need, how many applications per year, and the best timing — with separate US and Canadian timing notes because Canadian pre-emergent timing is typically 4–6 weeks later than equivalent US zones. You can also use the full fertilizer calculator for NPK ratios and soil test-based recommendations.