Red Deer, Alberta

Red Deer, Alberta52.2668, -113.8020

Mowing

When you can next cut it, and the best slot this weekend.

Best weekend slot

Nothing doing

Verdict: Not worth it

Nothing to cut — the grass is barely growing (growth potential 0.00). Conditions themselves are fine. And nothing else in the next 10 days either.

Next mow

Not in the next 10 days

Verdict: Not worth it

Nothing to cut — the grass is barely growing (growth potential 0.02). Conditions themselves are fine.

  • Warning: Frost about. Monday 19 October has frosted hours. Stay off it until it lifts — walking on frosted grass bruises it, and mowing it ruptures the leaf. More
  • Worth watching: Growth has stalled. The lawn is hard and barely growing. Cutting it now takes more than it gives — leave it longer and wait for rain.

The next 10 days

Each row is a day, morning on the left. The more solid a block, the more of the forecast runs agree you can mow. Open a day for the hour-by-hour forecast behind it.

  1. Monday 19 October: nothing to cut. Nothing to cut — the grass is barely growing (growth potential 0.02). Conditions themselves are fine.
    Monday 19 October, hour by hour
    5am6am7am8am9am10am11ammidday1pm2pm3pm4pm5pm6pm7pm8pm
    Chance————<5%<5%>95%>95%>95%>95%>95%>95%>95%>95%——
    Verdictnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growing
    Rainchance0%0%0%0%0%0%0%0%0%0%0%0%0%0%0%0%
    Rainmm————————————————
    Grassdrydrydrydrydrydrydrydrydrydrydrydrydrydrydrydry
    Groundfirmfrozenfrozenfrozenfirmfirmfirmfirmfirmfirmfirmfirmfirmfirmfirmfirm
    Temp2°1°0°0°0°2°4°7°9°9°11°11°10°9°7°6°
    Windkm/h556677556667881010
    Daylight————✓✓✓✓✓✓✓✓✓✓——

    Growth: barely growing (growth potential 0.02). Not enough to be worth cutting, which is why no hour is recommended today whatever the weather does.Chance is the share of 82 forecast runs — the same weather models re-run from slightly different starting conditions — in which you could have mowed that hour. The rows below it are what those runs expect on average, which is why an hour can look reasonable line by line and still fall short: the chance only counts runs where everything came together at once. Hover any cell for what the runs that ruled it out actually hit.

    Monday 19 OctoberConfident

    Nothing to cut — the grass is barely growing (growth potential 0.02). Conditions themselves are fine.

    >95% nothing to cut. Every forecast run agrees.

    Nothing to cut. The odds below describe the weather only — growth decides whether a cut is wanted, and it is judged separately.

    Limiting factor:growth

  2. Tuesday 20 October: nothing to cut. Nothing to cut — the grass is barely growing (growth potential 0.01). Conditions themselves are fine.
    Tuesday 20 October, hour by hour
    5am6am7am8am9am10am11ammidday1pm2pm3pm4pm5pm6pm7pm8pm
    Chance————<5%<5%>95%>95%>95%>95%>95%>95%>95%>95%——
    Verdictnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growing
    Rainchance0%0%0%0%0%0%0%0%0%0%0%0%0%0%0%0%
    Rainmm————————————————
    Grassdrydampdampdampdampdrydrydrydrydrydrydrydrydrydrydry
    Groundfrozenfrozenfrozenfrozenfrozenfirmfirmfirmfirmfirmfirmfirmfirmfirmfirmfirm
    Temp0°-1°-1°-2°-1°1°4°7°10°11°12°12°11°10°8°7°
    Windkm/h67888755812151616141515
    Daylight————✓✓✓✓✓✓✓✓✓✓——

    Growth: barely growing (growth potential 0.01). Not enough to be worth cutting, which is why no hour is recommended today whatever the weather does.Chance is the share of 82 forecast runs — the same weather models re-run from slightly different starting conditions — in which you could have mowed that hour. The rows below it are what those runs expect on average, which is why an hour can look reasonable line by line and still fall short: the chance only counts runs where everything came together at once. Hover any cell for what the runs that ruled it out actually hit.

    Tuesday 20 OctoberConfident

    Nothing to cut — the grass is barely growing (growth potential 0.01). Conditions themselves are fine.

    >95% nothing to cut. Every forecast run agrees.

    Nothing to cut. The odds below describe the weather only — growth decides whether a cut is wanted, and it is judged separately.

    Limiting factor:growth

  3. Wednesday 21 October: nothing to cut. Nothing to cut — the grass is barely growing (growth potential 0.04). Conditions themselves are fine.
    Wednesday 21 October, hour by hour
    5am6am7am8am9am10am11ammidday1pm2pm3pm4pm5pm6pm7pm8pm
    Chance————<5%>95%>95%>95%>95%>95%>95%>95%>95%>95%——
    Verdictnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growing
    Rainchance0%0%0%0%0%0%0%0%0%0%0%0%0%0%0%0%
    Rainmm————————————————
    Grassdrydrydrydrydrydrydrydrydrydrydrydrydrydrydrydry
    Groundfirmfirmfirmfrozenfirmfirmfirmfirmfirmfirmfirmfirmfirmfirmfirmfirm
    Temp2°2°2°1°2°4°8°11°14°17°18°19°18°15°13°13°
    Windkm/h141313121210765566551113
    Daylight————✓✓✓✓✓✓✓✓✓✓——

    Growth: barely growing (growth potential 0.04). Not enough to be worth cutting, which is why no hour is recommended today whatever the weather does.Chance is the share of 82 forecast runs — the same weather models re-run from slightly different starting conditions — in which you could have mowed that hour. The rows below it are what those runs expect on average, which is why an hour can look reasonable line by line and still fall short: the chance only counts runs where everything came together at once. Hover any cell for what the runs that ruled it out actually hit.

    Wednesday 21 OctoberConfident

    Nothing to cut — the grass is barely growing (growth potential 0.04). Conditions themselves are fine.

    >95% nothing to cut. Every forecast run agrees.

    Nothing to cut. The odds below describe the weather only — growth decides whether a cut is wanted, and it is judged separately.

    Limiting factor:growth

  4. Thursday 22 October: nothing to cut. Nothing to cut — the grass is barely growing (growth potential 0.09). Conditions themselves are fine.
    Thursday 22 October, hour by hour
    5am6am7am8am9am10am11ammidday1pm2pm3pm4pm5pm6pm7pm8pm
    Chance————<5%>95%>95%>95%>95%>95%>95%>95%>95%>95%——
    Verdictnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growing
    Rainchance0%0%0%0%0%0%0%0%0%0%0%1%0%0%1%2%
    Rainmm————————————————
    Grassdrydrydrydrydrydrydrydrydrydrydrydrydrydrydrydry
    Groundfirmfirmfirmfrozenfirmfirmfirmfirmfirmfirmfirmfirmfirmfirmfirmfirm
    Temp4°3°3°2°3°5°9°12°14°16°17°16°15°13°12°10°
    Windkm/h354321212581011121314
    Daylight————✓✓✓✓✓✓✓✓✓✓——

    Growth: barely growing (growth potential 0.09). Not enough to be worth cutting, which is why no hour is recommended today whatever the weather does.Chance is the share of 82 forecast runs — the same weather models re-run from slightly different starting conditions — in which you could have mowed that hour. The rows below it are what those runs expect on average, which is why an hour can look reasonable line by line and still fall short: the chance only counts runs where everything came together at once. Hover any cell for what the runs that ruled it out actually hit.

    Thursday 22 OctoberConfident

    Nothing to cut — the grass is barely growing (growth potential 0.09). Conditions themselves are fine.

    >95% nothing to cut. Every forecast run agrees.

    Nothing to cut. The odds below describe the weather only — growth decides whether a cut is wanted, and it is judged separately.

    Limiting factor:growth

  5. Friday 23 October: nothing to cut. Nothing to cut — the grass is barely growing (growth potential 0.02).
    Friday 23 October, hour by hour
    5am6am7am8am9am10am11ammidday1pm2pm3pm4pm5pm6pm7pm8pm
    Chance————<5%<5%<5%<5%<5%<5%<5%<5%<5%<5%——
    Verdictnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growing
    Rainchance10%6%11%22%28%20%24%20%17%19%30%19%17%26%12%15%
    Rainmm0.10.10.20.60.60.70.60.30.50.30.50.30.20.40.10.2
    Grassdampdampdampwetwetwetwetwetwetwetsoakedsoakedwetsoakedsoakedsoaked
    Groundfirmfirmfirmfirmfirmfirmfirmfirmfirmfirmfirmfirmfirmfirmfirmfirm
    Temp5°5°5°4°4°4°4°4°4°4°4°4°4°4°3°3°
    Windkm/h891114161718192124262728282828
    Daylight————✓✓✓✓✓✓✓✓✓✓——

    Growth: barely growing (growth potential 0.02). Not enough to be worth cutting, which is why no hour is recommended today whatever the weather does.Chance is the share of 82 forecast runs — the same weather models re-run from slightly different starting conditions — in which you could have mowed that hour. The rows below it are what those runs expect on average, which is why an hour can look reasonable line by line and still fall short: the chance only counts runs where everything came together at once. Hover any cell for what the runs that ruled it out actually hit.

    Friday 23 OctoberReasonably confident

    Nothing to cut — the grass is barely growing (growth potential 0.02).

    <5% nothing to cut. Almost every run found the grass barely growing.

    Nothing to cut. The odds below describe the weather only — growth decides whether a cut is wanted, and it is judged separately.

    Limiting factor:growth

  6. Saturday 24 October: nothing to cut. Nothing to cut — the grass is barely growing (growth potential 0.00). Conditions themselves are fine.
    Saturday 24 October, hour by hour
    5am6am7am8am9am10am11ammidday1pm2pm3pm4pm5pm6pm7pm8pm
    Chance————<5%<5%<5%<5%<5%<5%<5%<5%<5%<5%——
    Verdictnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growing
    Rainchance3%6%5%3%3%4%3%6%3%2%6%3%4%6%5%4%
    Rainmm—0.10.1————0.1—————0.1——
    Grasswetwetdampdampdampdampdampdampdrydrydrydrydrydrydrydry
    Groundfirmfirmfirmfrozenfrozenfirmfirmfirmfirmfirmfirmfirmfirmfirmfirmfrozen
    Temp0°0°0°0°0°1°2°2°3°3°4°2°2°1°1°0°
    Windkm/h29302826252627282726242220191818
    Daylight————✓✓✓✓✓✓✓✓✓✓——

    Growth: barely growing (growth potential 0.00). Not enough to be worth cutting, which is why no hour is recommended today whatever the weather does.Chance is the share of 82 forecast runs — the same weather models re-run from slightly different starting conditions — in which you could have mowed that hour. The rows below it are what those runs expect on average, which is why an hour can look reasonable line by line and still fall short: the chance only counts runs where everything came together at once. Hover any cell for what the runs that ruled it out actually hit.

    Saturday 24 OctoberReasonably confident

    Nothing to cut — the grass is barely growing (growth potential 0.00). Conditions themselves are fine.

    <5% nothing to cut. Almost every run found the grass barely growing.

    Nothing to cut. The odds below describe the weather only — growth decides whether a cut is wanted, and it is judged separately.

    Limiting factor:growth

  7. Sunday 25 October: nothing to cut. Nothing to cut — the grass is barely growing (growth potential 0.00).
    Sunday 25 October, hour by hour
    5am6am7am8am9am10am11ammidday1pm2pm3pm4pm5pm6pm7pm8pm
    Chance————<5%<5%<5%<5%<5%<5%<5%<5%<5%<5%——
    Verdictnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growing
    Rainchance11%3%4%5%15%12%10%2%4%8%1%6%3%5%6%7%
    Rainmm0.10.1——0.20.10.1——0.1——————
    Grassdampdampdampdampdampdampdampdampdampdampdampdampdampdampdampdamp
    Groundfrozenfrozenfrozenfrozenfirmfirmfirmfirmfirmfirmfirmfirmfirmfrozenfrozenfrozen
    Temp-2°-2°-2°-2°-2°-1°-1°-1°0°0°0°0°0°0°0°-1°
    Windkm/h111098776544445567
    Daylight————✓✓✓✓✓✓✓✓✓✓——

    Growth: barely growing (growth potential 0.00). Not enough to be worth cutting, which is why no hour is recommended today whatever the weather does.Chance is the share of 82 forecast runs — the same weather models re-run from slightly different starting conditions — in which you could have mowed that hour. The rows below it are what those runs expect on average, which is why an hour can look reasonable line by line and still fall short: the chance only counts runs where everything came together at once. Hover any cell for what the runs that ruled it out actually hit.

    Sunday 25 OctoberReasonably confident

    Nothing to cut — the grass is barely growing (growth potential 0.00).

    <5% nothing to cut. Almost every run found the grass barely growing.

    Nothing to cut. The odds below describe the weather only — growth decides whether a cut is wanted, and it is judged separately.

    Limiting factor:growth

  8. Monday 26 October: nothing to cut. Nothing to cut — the grass is barely growing (growth potential 0.00). Conditions themselves are fine.
    Monday 26 October, hour by hour
    5am6am7am8am9am10am11ammidday1pm2pm3pm4pm5pm6pm7pm8pm
    Chance————<5%<5%<5%<5%<5%<5%<5%<5%<5%<5%——
    Verdictnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growing
    Rainchance8%4%9%4%5%4%9%5%5%4%8%4%7%4%3%1%
    Rainmm0.10.10.1—0.1—0.20.1——0.1—0.1———
    Grassdampdampdampdampdampdampdampdampdampdampdampdampdampdampdampdamp
    Groundfrozenfrozenfrozenfrozenfirmfirmfirmfirmfirmfirmfirmfirmfirmfrozenfrozenfrozen
    Temp-3°-3°-2°-2°-1°0°0°1°1°2°2°2°2°2°2°1°
    Windkm/h1717171818181817161412108654
    Daylight————✓✓✓✓✓✓✓✓✓✓——

    Growth: barely growing (growth potential 0.00). Not enough to be worth cutting, which is why no hour is recommended today whatever the weather does.Chance is the share of 82 forecast runs — the same weather models re-run from slightly different starting conditions — in which you could have mowed that hour. The rows below it are what those runs expect on average, which is why an hour can look reasonable line by line and still fall short: the chance only counts runs where everything came together at once. Hover any cell for what the runs that ruled it out actually hit.

    Monday 26 OctoberReasonably confident

    Nothing to cut — the grass is barely growing (growth potential 0.00). Conditions themselves are fine.

    <5% nothing to cut. Almost every run found the grass barely growing.

    Nothing to cut. The odds below describe the weather only — growth decides whether a cut is wanted, and it is judged separately.

    Limiting factor:growth

  9. Tuesday 27 October: nothing to cut. Nothing to cut — the grass is barely growing (growth potential 0.00).
    Tuesday 27 October, hour by hour
    5am6am7am8am9am10am11ammidday1pm2pm3pm4pm5pm6pm7pm8pm
    Chance————<5%<5%<5%<5%<5%<5%<5%<5%<5%<5%——
    Verdictnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growing
    Rainchance3%5%6%2%3%4%5%3%6%3%4%5%3%5%3%8%
    Rainmm—————————0.1——0.1——0.1
    Grasssoakedsoakedsoakedsoakedsoakedsoakedsoakedsoakedsoakedsoakedsoakedsoakedsoakedsoakedsoakedsoaked
    Groundfrozenfrozenfrozenfrozenfrozenfrozenfrozensnowsnowfrozenfrozenfrozenfrozenfrozenfrozenfrozen
    Temp-3°-3°-2°-2°-2°-1°-1°-1°-1°-1°-1°-1°-1°-1°-1°-1°
    Windkm/h6778899101011111213141415
    Daylight————✓✓✓✓✓✓✓✓✓✓——

    Growth: barely growing (growth potential 0.00). Not enough to be worth cutting, which is why no hour is recommended today whatever the weather does.Chance is the share of 82 forecast runs — the same weather models re-run from slightly different starting conditions — in which you could have mowed that hour. The rows below it are what those runs expect on average, which is why an hour can look reasonable line by line and still fall short: the chance only counts runs where everything came together at once. Hover any cell for what the runs that ruled it out actually hit.

    Tuesday 27 OctoberLow confidence this far out

    Nothing to cut — the grass is barely growing (growth potential 0.00).

    <5% nothing to cut. Almost every run found the grass barely growing.

    Nothing to cut. The odds below describe the weather only — growth decides whether a cut is wanted, and it is judged separately.

    Limiting factor:growth

  10. Wednesday 28 October: nothing to cut. Nothing to cut — the grass is barely growing (growth potential 0.00).
    Wednesday 28 October, hour by hour
    5am6am7am8am9am10am11ammidday1pm2pm3pm4pm5pm6pm7pm8pm
    Chance————<5%<5%<5%<5%<5%<5%<5%<5%<5%———
    Verdictnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingnothing to cut — the grass is barely growingAlready goneAlready goneAlready gone
    Rainchance11%4%8%7%10%8%8%8%9%4%7%8%13%···
    Rainmm0.10.10.10.10.10.10.10.10.10.1—0.10.1···
    Grasssoakedsoakedsoakedsoakedsoakedsoakedsoakedsoakedsoakedsoakedsoakedsoakedsoaked···
    Groundfrozenfrozenfrozenfrozenfrozenfrozenfrozenfrozenfrozenfrozenfrozenfrozenfrozen···
    Temp-3°-3°-3°-3°-3°-3°-3°-3°-3°-4°-4°-5°-5°···
    Windkm/h1716161515141312109889···
    Daylight————✓✓✓✓✓✓✓✓✓···

    Growth: barely growing (growth potential 0.00). Not enough to be worth cutting, which is why no hour is recommended today whatever the weather does.Chance is the share of 82 forecast runs — the same weather models re-run from slightly different starting conditions — in which you could have mowed that hour. The rows below it are what those runs expect on average, which is why an hour can look reasonable line by line and still fall short: the chance only counts runs where everything came together at once. Hover any cell for what the runs that ruled it out actually hit.

    Wednesday 28 OctoberLow confidence this far out

    Nothing to cut — the grass is barely growing (growth potential 0.00).

    <5% nothing to cut. Almost every run found the grass barely growing.

    Nothing to cut. The odds below describe the weather only — growth decides whether a cut is wanted, and it is judged separately.

    Limiting factor:growth

good to go touch and go dark, frost or snow already goneFainter means fewer forecast runs agree.

How you feel about mowing

Sensible middle ground.

Petrol or battery. The baseline.

Growth

How fast it is growing, and when it will need cutting again.

2%Barely growing

Of the fastest this grass could grow. The turf-industry measure, from today's temperature and day length.

The lawn is barely growing, so it does not need cutting. Leave it — taking leaf off a sward that cannot replace it costs more than it gives.

Held back by both temperature and short days — 10.4 hours of daylight at 5°C.

Over the next 10 days
about 1mm of leaf
Next cut due
not within the next ten days

This only knows temperature and day length. Feeding, watering, shade and cutting height all move it, so treat it as a rough guide.

Worked out from the PACE Turf growth potential model and day length —how and why.

Seeding

Soil temperature at germination depth, and when the window opens.

Soil temperature in Red Deer, Alberta

5.1°C41°F

at 6cm — germination depth

Too cold to seed — 5.1°C at 6cm and not warming.

Cooling over the next 10 days.

Cross-checks against an independent estimate from air temperature (6.9°C), which agrees to within 1.0°C.

Most cool-season lawns in the northern US and Canada are bluegrass, tall fescue, or a mix of the two. We assume that, and use 12.5°C as the seeding threshold.

Thresholds for every species

The differences are small. Ryegrass is the quickest off the mark; bluegrass is the slowest and wants the warmest soil. Everything else sits between.

Soil temperature at 6cm for reliable germination. Sources onthe method page.
SpeciesSoil neededDays to sprout
Perennial ryegrass8°C5–10
Red / chewings fescue8–10°C10–14
Tall fescuelikely yours10–12°C10–14
Browntop bentColonial bentgrass10–12°C14–21
Smooth-stalked meadow grassKentucky bluegrasslikely yours12–13°C14–28

Feeding

Why timing decides whether a feed does anything at all.

Coming in the app

Grass takes up nitrogen when it is growing. Feed a lawn that has stopped and most of it washes past the roots — which is why timing beats product choice.

Right now this lawn is not growing fast enough to make much use of a feed.

The app will work out the actual feeding windows for your lawn — along with weed control, scarifying and moss treatment — and tell you when they open without you having to check.

Why timing beats product choice

Red Deer, Alberta in detail

Soil temperature in Red Deer, Alberta is currently 5.1°C at 6cm, and falling about 5.5°C over the next 10 days. That depth matters because it is where grass seed sits and where roots start working, and it lags air temperature by days — which is why a warm afternoon here tells you very little on its own.

Lawns in this area are typically Kentucky bluegrass with tall fescue, the usual mix for cool-season lawns at this latitude. That blend needs the soil to hold above 12.5°C before seed germinates reliably. Too cold to seed — 5.1°C at 6cm and not warming.

None of the next 10 days are worth getting the mower out for. As for the weekend: nothing doing. Nothing to cut — the grass is barely growing (growth potential 0.00). Conditions themselves are fine. And nothing else in the next 10 days either.

Nothing in the current forecast for Red Deer opens a sensible window. The ground reads as firm after 1mm rain over the last week, medium (loam) soil, and that is usually what decides it at this time of year.

There is frost in the forecast for Red Deer, Alberta: Monday 19 October has hours cold enough to freeze the leaf. Stay off the grass until it lifts — mowing frosted turf ruptures the cells and the damage shows for weeks.

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Chances counted across 82 forecast runs from NCEP GEFS, 25km and ECMWF IFS ensemble, 25km. Forecast from Open-Meteo, refreshed through the day. Soil temperature is modelled, not measured — how that works and where the thresholds come from.