Weed Control Calendar
Month-by-month weed-control schedule for two climate bands: Northern/Cold (USDA 3 to 6, NRCan 0 to 5b) and Southern/Mild (USDA 7 to 10, NRCan 6 to 9). Pre-emergent timing, manual passes, edging, mulch refresh, and fall cleanup, plus a notes column for what actually happened.
Pair with the Weed Removal Method Picker calculator and the how to get rid of weeds anchor guide. Size mulch loads with the Mulch Calculator; coordinate watering with the Watering Schedule Log.
Weed Control Calendar
Two-band month-by-month weed control schedule. Pick your band (Northern/Cold or Southern/Mild) and use the right column to log what you actually did.
How to use this calendar
Pick your climate band (Northern/Cold or Southern/Mild) using the zone reference below, then follow the month rows for that band. Each month lists the priority tasks; the right column is for the date you actually did the work and any notes. Soil-temperature triggers (50 to 55 F / 10 to 13 C at 4 inch / 10 cm depth) override the calendar in early-spring weeks; if your soil is colder than that, hold pre-emergent until it hits the trigger. The calendar assumes mixed lawn + garden bed; skip the lawn rows if you are bed-only.
Climate band reference
| Band | USDA zones | NRCan zones | Typical regions |
|---|---|---|---|
| Northern / Cold | 3, 4, 5, 6 | 0, 1, 2, 3, 4, 5a, 5b | Most populated Canada (Halifax, Montreal, Ottawa, Toronto, Winnipeg, Calgary, Edmonton); Northern US (New England, upper Midwest, Mountain West, Pacific Northwest interior); Alaska |
| Southern / Mild | 7, 8, 9, 10 | 6, 7, 8, 9 | US South + Southwest (Atlanta, Dallas, Houston, Phoenix, Florida, coastal California); Canadian Pacific coast (Vancouver, Victoria, parts of Vancouver Island) |
Northern / Cold band: monthly schedule
| Month | Priority tasks | Date done / notes |
|---|---|---|
| January | Plan: order corn gluten or pre-emergent, sharpen weeders, inventory mulch supply. | |
| February | Inventory check: cardboard saved for new beds, mulch source identified, soil thermometer in hand. | |
| March | Late month: start checking soil temp at 4 in (10 cm) depth. Edge beds when ground thaws. Cut down winter weeds with string trimmer. | |
| April | Watch forsythia bloom. When soil hits 50 to 55 F (10 to 13 C): apply pre-emergent (corn gluten or chemical, where legal). Pull early dandelions after rain. | |
| May | Lawn: spot-treat broadleaf weeds (manual dig or selective herbicide where legal). Beds: cardboard smother any new bed prep, mulch refresh 1 to 2 in (2.5 to 5 cm) on existing beds. | |
| June | Weekly 5-minute pull pass on each bed; pull crabgrass before it tillers. Edge beds; sharp edges keep grass out. Watch for bindweed and quackgrass. | |
| July | Heat-of-summer maintenance: vinegar or boiling water on patio cracks, weekly pulling on beds. Mow lawn at 3 in (7.5 cm) for shade-out density. | |
| August | Fall planning: identify problem weeds for next year. Lawn: overseed prep (de-thatch, aerate). Pull before any weeds set seed. | |
| September | Lawn overseed; dense lawn shades out crabgrass next year. Fall pre-emergent for winter annuals (where legal). Last big mulch refresh before frost. | |
| October | Fall cleanup: pull seed-bearing weeds before winter. Cardboard smother any beds going dormant; mulch over the cardboard. Edge beds. | |
| November | Winterize: drain hoses, store sprayers, winter-coat metal on weeders, oil hori-hori. Mulch any bare spots to limit winter-annual weeds. | |
| December | Off-season: review notes column. What worked, what regrew. Update next-year plan. |
Southern / Mild band: monthly schedule
| Month | Priority tasks | Date done / notes |
|---|---|---|
| January | Late month: start checking soil temp at 4 in (10 cm) depth (Southern band warms early). Inventory mulch and cardboard. | |
| February | Soil-temp window opens: when 50 to 55 F (10 to 13 C) reached, apply pre-emergent (corn gluten or chemical, where legal). Pull early winter annuals. | |
| March | Crabgrass germination is active; second pre-emergent application 4 to 6 weeks after first if using corn gluten. Lawn: spot-treat broadleaf weeds. Edge beds. | |
| April | Cardboard smother any new bed prep before summer heat. Mulch refresh 1 to 2 in (2.5 to 5 cm) on existing beds. Pull bindweed and crabgrass weekly. | |
| May | Heat ramping: vinegar or boiling water effective on patio cracks. Weekly bed pull pass. Mow lawn high (3 to 4 in / 7.5 to 10 cm). | |
| June | Maintenance mode: weekly pull, mulch refresh on areas that thinned. Watch for warm-season perennial weeds (Bermuda grass, nutsedge). | |
| July | Hot dry weeks: vinegar most effective. Avoid pulling in mid-day heat (water deep, pull early morning). Edge beds. | |
| August | Late-summer rest period for some weeds. Plan fall pre-emergent for winter annuals. Pull seed-bearing summer weeds before they finish. | |
| September | Soil cooling toward fall pre-emergent window: when soil drops below 70 F (21 C), apply fall pre-emergent for winter annual prevention (where legal). | |
| October | Cool-season grass overseed (where applicable). Cardboard smother bed prep for spring planting; mulch over. | |
| November | Continued winter-annual prevention: pull as germinating, refresh mulch where thin. Edge beds while soil is workable. | |
| December | Off-season planning: review notes column, source mulch and cardboard, sharpen tools, winter-coat metal. Prep for January start. |
Quick triggers
| Trigger | Threshold | What to do |
|---|---|---|
| Soil temp at 4 in (10 cm) | 50 to 55 F (10 to 13 C) | |
| Forsythia bloom | Full bloom | |
| Soil temp dropping in fall | Below 70 F (21 C) | |
| Average last-frost date passed | Local date | |
| Average first-frost date approaching | 2 to 4 weeks out |
Method legend
| Method | Use for | Effective on | Notes |
|---|---|---|---|
| Manual pull / dig | Small areas, lawn taproots | Annual + perennial when full root removed | Pull when wet; stand-up weeder for taproots |
| Cardboard smother + mulch | Bed prep, large areas, organic-only | All weeds; runners need 12 to 18 weeks | 3 to 4 in (7.5 to 10 cm) mulch on top |
| Boiling water | Patio cracks, gravel paths | Annual weeds (top burn) | Free; perennials may resprout |
| Vinegar (5 to 30 percent) | Patio cracks on hot dry days | Annual weeds (top burn) | 10 to 30 percent more effective; eye protection |
| Corn gluten meal | Lawn pre-emergent, organic | Germinating seeds (not established weeds) | Apply at soil-temp trigger; repeat 4 to 6 weeks |
| Selective broadleaf herbicide | Lawn perennial broadleaf | Dandelion, plantain, clover, etc. | Where legal (US: most states. Canada: not in QC, ON, NS, NB, PEI) |
| Glyphosate (non-selective) | Spot regrowth, gravel reset | All plant tissue it touches | Where legal; surgical use only; no drift to beds |
| Chemical pre-emergent | Lawn crabgrass prevention | Germinating annual grass seed | Where legal; apply at soil-temp trigger |
Year-end notes & observations
Frequently Asked Questions
Which band do I use, Northern or Southern?
Use Northern/Cold if you are in USDA zones 3 to 6 or NRCan zones 0 to 5b. This covers most populated Canada (Halifax, Montreal, Ottawa, Toronto, Winnipeg, Calgary, Edmonton, most of BC interior) and the Northern US (New England, upper Midwest, Mountain West, Pacific Northwest interior). Use Southern/Mild if you are in USDA zones 7 to 10 or NRCan zones 6 to 9. This covers the US South and Southwest (Atlanta, Dallas, Phoenix, Houston, Florida, coastal California) plus Canadian Pacific coastal areas (Vancouver, Victoria, parts of Vancouver Island). If you are on a band boundary, follow the colder of the two until soil temps confirm otherwise.
What is the soil-temperature trigger for crabgrass pre-emergent?
50 to 55 F (10 to 13 C) at 4 inch (10 cm) depth, before germination. The visual cue across most of North America is forsythia in full bloom. Northern band: typically mid-April to early May. Southern band: typically late February to mid-March. Inexpensive soil thermometers ($10 to $15 USD / $14 to $20 CAD) make this trigger trivial to track. Apply within a 7 to 10 day window after the trigger; later applications miss germinating seeds.
What if I do not want to use any chemicals?
The calendar still works. Substitute corn gluten meal in pre-emergent slots (apply at the same soil-temperature trigger, repeat every 4 to 6 weeks through the germination window). Substitute manual pull or cardboard smother in post-emergent slots. Boiling water replaces vinegar or herbicide for patio cracks. Mulch refresh, edging, and fall cleanup are unchanged. The schedule is the same; only the active method differs. This is the only legal option in Quebec, Ontario, Nova Scotia, New Brunswick, and Prince Edward Island.
How do I track this calendar over the season?
The right-side notes column for each month captures what you actually did and what you noticed. Use it to log: dates of soil-temp readings, pre-emergent application date and product, weather notes (early or late spring), problem weed sightings, lawn density observations. By year three you will have a personal calibration for your specific yard that beats any general advice.