AL2, Hertsmere
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 0.07). Conditions themselves are fine. And nothing else in the next 10 days either.
Next mow
Nothing above 65% this week
Verdict: Not worth it
0.6mm of rain falling.
Best chance is Monday.
- Worth watching: Ground still soft. 43mm rain over the last week, medium (loam) soil. A mower will mark it, and a ride-on will rut it. More
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.
Monday 19 October: no hours worth using. No — grass damp, rain earlier that day.
Monday 19 October, hour by hour 5am 6am 7am 8am 9am 10am 11am midday 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm Chance — — — — — — — — — — — — — — — — Verdict Already gone Already gone Already gone Already gone Already gone Already gone Already gone Already gone Already gone Forget it Forget it Forget it Forget it dark dark dark Rainchance · · · · · · · · · — — — — — — — Rainmm · · · · · · · · · — — — — — — — Grass · · · · · · · · · soaked soaked soaked wet wet wet damp Ground · · · · · · · · · firm firm firm firm firm firm firm Temp · · · · · · · · · 12° 12° 12° 12° 11° 11° 11° Windkm/h · · · · · · · · · 12 12 13 10 7 6 8 Daylight · · · · · · · · · ✓ ✓ ✓ ✓ — — — Growth: barely growing (growth potential 0.15). Enough to be worth cutting. Growth decides whether a cut is wanted, not how well it will go, so it is not one of the rows above and does not move the chances.
Monday 19 OctoberConfident
No — grass damp, rain earlier that day.
Limiting factor:grass wetness
Tuesday 20 October: no hours worth using. No — 0.6mm of rain falling.
Tuesday 20 October, hour by hour 5am 6am 7am 8am 9am 10am 11am midday 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm Chance — — — — — — — — — — — — — — — — Verdict dark dark dark Forget it 0.6mm of rain falling 0.5mm of rain falling 0.6mm of rain falling 1.6mm of rain falling 0.6mm of rain falling 0.2mm of rain falling 0.1mm of rain falling Forget it Forget it dark dark dark Rainchance — — — — — — — — — — — — — — — — Rainmm — — — — 0.6 0.5 0.6 1.6 0.6 0.2 0.1 — — — — — Grass soaked soaked soaked soaked soaked soaked soaked soaked soaked soaked soaked soaked soaked soaked soaked soaked Ground firm firm firm firm firm firm firm firm firm firm firm firm firm firm firm firm Temp 12° 12° 12° 12° 12° 12° 12° 12° 12° 12° 13° 13° 13° 12° 12° 11° Windkm/h 13 15 13 14 13 13 12 13 9 9 8 12 10 13 15 14 Daylight — — — ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ — — — Growth: barely growing (growth potential 0.19). Enough to be worth cutting. Growth decides whether a cut is wanted, not how well it will go, so it is not one of the rows above and does not move the chances.
Tuesday 20 OctoberConfident
No — 0.6mm of rain falling.
Limiting factor:grass wetness
Wednesday 21 October: no hours worth using. No — 0.6mm of rain falling.
Wednesday 21 October, hour by hour 5am 6am 7am 8am 9am 10am 11am midday 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm Chance — — — — — — — — — — — — — — — — Verdict dark dark dark 0.6mm of rain falling 0.2mm of rain falling 0.4mm of rain falling Forget it 0.5mm of rain falling Forget it 0.2mm of rain falling 0.2mm of rain falling 0.2mm of rain falling 1.2mm of rain falling dark dark dark Rainchance — — — — — — — — — — — — — — — — Rainmm — — 0.1 0.6 0.2 0.4 — 0.5 0.1 0.2 0.2 0.2 1.2 1.2 1.2 0.4 Grass soaked soaked soaked soaked soaked soaked soaked soaked soaked soaked soaked soaked soaked soaked soaked soaked Ground firm firm firm firm firm firm firm firm firm firm firm firm firm firm firm firm Temp 9° 9° 10° 9° 10° 10° 11° 12° 12° 13° 13° 12° 11° 9° 8° 7° Windkm/h 9 12 14 13 17 18 16 19 16 14 11 11 19 30 36 35 Daylight — — — ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ — — — Growth: barely growing (growth potential 0.10). Enough to be worth cutting. Growth decides whether a cut is wanted, not how well it will go, so it is not one of the rows above and does not move the chances.
Wednesday 21 OctoberConfident
No — 0.6mm of rain falling.
Limiting factor:grass wetness
Thursday 22 October: nothing to cut. Nothing to cut — the grass is barely growing (growth potential 0.07).
Thursday 22 October, hour by hour 5am 6am 7am 8am 9am 10am 11am midday 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm Chance — — — — — — — — — — — — — — — — Verdict nothing to cut — the grass is barely growing nothing to cut — the grass is barely growing nothing to cut — the grass is barely growing nothing to cut — the grass is barely growing nothing to cut — the grass is barely growing nothing to cut — the grass is barely growing nothing to cut — the grass is barely growing nothing to cut — the grass is barely growing nothing to cut — the grass is barely growing nothing to cut — the grass is barely growing nothing to cut — the grass is barely growing nothing to cut — the grass is barely growing nothing to cut — the grass is barely growing nothing to cut — the grass is barely growing nothing to cut — the grass is barely growing nothing to cut — the grass is barely growing Rainchance — — — — — — — — — — — — — — — — Rainmm 0.5 0.5 0.5 — — — — — — — — — — — — 0.2 Grass soaked soaked soaked soaked soaked soaked soaked soaked soaked soaked soaked wet wet soaked soaked soaked Ground firm firm firm firm firm firm firm firm firm firm firm firm firm firm firm firm Temp 6° 6° 6° 7° 7° 8° 9° 10° 10° 11° 11° 11° 11° 10° 9° 9° Windkm/h 6 5 5 6 8 9 10 11 11 12 12 11 10 9 9 11 Daylight — — — ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ — — — Growth: barely growing (growth potential 0.07). Not enough to be worth cutting, which is why no hour is recommended today whatever the weather does.
Thursday 22 OctoberConfident
Nothing to cut — the grass is barely growing (growth potential 0.07).
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
Friday 23 October: nothing to cut. Nothing to cut — the grass is barely growing (growth potential 0.09).
Friday 23 October, hour by hour 5am 6am 7am 8am 9am 10am 11am midday 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm Chance — — — — — — — — — — — — — — — — Verdict nothing to cut — the grass is barely growing nothing to cut — the grass is barely growing nothing to cut — the grass is barely growing nothing to cut — the grass is barely growing nothing to cut — the grass is barely growing nothing to cut — the grass is barely growing nothing to cut — the grass is barely growing nothing to cut — the grass is barely growing nothing to cut — the grass is barely growing nothing to cut — the grass is barely growing nothing to cut — the grass is barely growing nothing to cut — the grass is barely growing nothing to cut — the grass is barely growing nothing to cut — the grass is barely growing nothing to cut — the grass is barely growing nothing to cut — the grass is barely growing Rainchance — — — — — — — — — — — — — — — — Rainmm 0.2 0.2 0.2 0.5 0.5 0.5 1 1 1 0.1 0.1 0.1 0.2 0.2 0.2 0.6 Grass soaked soaked soaked soaked soaked soaked soaked soaked soaked soaked soaked soaked soaked soaked soaked soaked Ground soggy soggy soggy soggy soggy soggy soggy soggy soggy soggy soggy soggy soggy soggy soggy soggy Temp 12° 11° 10° 10° 9° 9° 9° 9° 9° 9° 9° 9° 8° 7° 7° 7° Windkm/h 24 24 24 19 13 12 19 32 42 44 42 41 40 39 37 36 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.
Friday 23 OctoberReasonably confident
Nothing to cut — the grass is barely growing (growth potential 0.09).
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
Saturday 24 October: nothing to cut. Nothing to cut — the grass is barely growing (growth potential 0.07). Conditions themselves are fine.
Saturday 24 October, hour by hour 5am 6am 7am 8am 9am 10am 11am midday 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm Chance — — — — — — — — — — — — — — — — Verdict nothing to cut — the grass is barely growing nothing to cut — the grass is barely growing nothing to cut — the grass is barely growing nothing to cut — the grass is barely growing nothing to cut — the grass is barely growing nothing to cut — the grass is barely growing nothing to cut — the grass is barely growing nothing to cut — the grass is barely growing nothing to cut — the grass is barely growing nothing to cut — the grass is barely growing nothing to cut — the grass is barely growing nothing to cut — the grass is barely growing nothing to cut — the grass is barely growing nothing to cut — the grass is barely growing nothing to cut — the grass is barely growing nothing to cut — the grass is barely growing Rainchance — — — — — — — — — — — — — — — — Rainmm — — — — — — — — — — — — 0.4 0.4 0.4 1.8 Grass soaked soaked soaked soaked soaked soaked soaked soaked wet damp dry dry soaked soaked soaked soaked Ground soggy soggy soggy soggy soggy soggy soggy soft soggy soggy soggy soggy soggy bog bog bog Temp 6° 6° 6° 6° 6° 7° 8° 9° 10° 11° 11° 11° 10° 9° 8° 9° Windkm/h 25 23 21 20 19 19 19 19 19 19 20 19 18 16 15 17 Daylight — — — ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ — — — Growth: barely growing (growth potential 0.07). Not enough to be worth cutting, which is why no hour is recommended today whatever the weather does.
Saturday 24 OctoberReasonably confident
Nothing to cut — the grass is barely growing (growth potential 0.07). Conditions themselves are fine.
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
Sunday 25 October: no hours worth using. No — 0.1mm of rain falling.
Sunday 25 October, hour by hour 5am 6am 7am 8am 9am 10am 11am midday 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm Chance — — — — — — — — — — — — — — — — Verdict dark dark 0.1mm of rain falling 0.1mm of rain falling 0.1mm of rain falling 0.1mm of rain falling 0.1mm of rain falling 0.1mm of rain falling Forget it Forget it Forget it Forget it dark dark dark dark Rainchance — — — — — — — — — — — — — — — — Rainmm 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 — — — — — — — — Grass soaked soaked soaked soaked soaked soaked soaked soaked soaked wet wet damp damp damp damp dry Ground soggy soggy soggy soggy soggy soggy soggy soggy soggy soggy soggy soggy soggy soggy soggy soggy Temp 14° 14° 15° 16° 16° 17° 18° 18° 17° 16° 15° 14° 13° 12° 11° 11° Windkm/h 19 21 23 25 28 30 32 33 34 34 33 33 32 32 32 32 Daylight — — ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ — — — — Growth: growing slowly (growth potential 0.31). Enough to be worth cutting. Growth decides whether a cut is wanted, not how well it will go, so it is not one of the rows above and does not move the chances.
Sunday 25 OctoberReasonably confident
No — 0.1mm of rain falling.
Limiting factor:grass wetness
Monday 26 October: nothing to cut. Nothing to cut — the grass is barely growing (growth potential 0.07).
Monday 26 October, hour by hour 5am 6am 7am 8am 9am 10am 11am midday 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm Chance — — — — — — — — — — — — — — — — Verdict nothing to cut — the grass is barely growing nothing to cut — the grass is barely growing nothing to cut — the grass is barely growing nothing to cut — the grass is barely growing nothing to cut — the grass is barely growing nothing to cut — the grass is barely growing nothing to cut — the grass is barely growing nothing to cut — the grass is barely growing nothing to cut — the grass is barely growing nothing to cut — the grass is barely growing nothing to cut — the grass is barely growing nothing to cut — the grass is barely growing nothing to cut — the grass is barely growing nothing to cut — the grass is barely growing nothing to cut — the grass is barely growing nothing to cut — the grass is barely growing Rainchance — — — — — — — — — — — — — — — — Rainmm — — 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 — — Grass damp damp wet soaked soaked soaked soaked soaked soaked soaked soaked soaked soaked soaked soaked soaked Ground soft soft soft soft soft soft soft soft soft soft soft soft soft soft soft soft Temp 6° 6° 6° 7° 8° 9° 10° 10° 11° 11° 11° 10° 10° 10° 10° 10° Windkm/h 8 9 10 11 14 15 17 17 16 15 13 13 14 14 14 13 Daylight — — ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ — — — — Growth: barely growing (growth potential 0.07). Not enough to be worth cutting, which is why no hour is recommended today whatever the weather does.
Monday 26 OctoberReasonably confident
Nothing to cut — the grass is barely growing (growth potential 0.07).
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
Tuesday 27 October: no hours worth using. No — 0.7mm of rain falling.
Tuesday 27 October, hour by hour 5am 6am 7am 8am 9am 10am 11am midday 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm Chance — — — — — — — — — — — — — — — — Verdict dark dark 0.7mm of rain falling 0.7mm of rain falling 0.7mm of rain falling 0.7mm of rain falling 0.7mm of rain falling 0.7mm of rain falling 0.1mm of rain falling 0.1mm of rain falling 0.1mm of rain falling 0.1mm of rain falling dark dark dark dark Rainchance — — — — — — — — — — — — — — — — Rainmm — — 0.7 0.7 0.7 0.7 0.7 0.7 0.1 0.1 0.1 0.1 0.1 0.1 — — Grass soaked soaked soaked soaked soaked soaked soaked soaked soaked soaked soaked soaked soaked soaked soaked soaked Ground soft soft soft soft soft soft soft soft soft soft soft soft soft soft soft soft Temp 14° 14° 15° 15° 15° 15° 15° 15° 15° 14° 14° 13° 12° 12° 11° 11° Windkm/h 24 25 25 26 26 27 28 28 28 26 24 22 20 18 17 16 Daylight — — ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ — — — — Growth: growing slowly (growth potential 0.26). Enough to be worth cutting. Growth decides whether a cut is wanted, not how well it will go, so it is not one of the rows above and does not move the chances.
Tuesday 27 OctoberLow confidence this far out
No — 0.7mm of rain falling.
Limiting factor:grass wetness
Wednesday 28 October: no hours worth using. No — 0.3mm of rain falling.
Wednesday 28 October, hour by hour 5am 6am 7am 8am 9am 10am 11am midday 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm Chance — — — — — — — — — — — — — — — — Verdict dark dark 0.3mm of rain falling 0.3mm of rain falling 0.3mm of rain falling 0.3mm of rain falling 0.3mm of rain falling 0.3mm of rain falling 0.3mm of rain falling 0.3mm of rain falling 0.3mm of rain falling 0.3mm of rain falling dark dark dark dark Rainchance — — — — — — — — — — — — — — — — Rainmm — — 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.8 0.8 Grass soaked soaked soaked soaked soaked soaked soaked soaked soaked soaked soaked soaked soaked soaked soaked soaked Ground soft soft soft soft soft soft soft soft soft soft soft soft soft soft soft soft Temp 9° 9° 10° 10° 11° 12° 12° 12° 13° 13° 13° 13° 13° 13° 13° 13° Windkm/h 13 13 14 15 17 18 19 20 21 21 22 22 22 22 22 22 Daylight — — ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ — — — — Growth: barely growing (growth potential 0.18). Enough to be worth cutting. Growth decides whether a cut is wanted, not how well it will go, so it is not one of the rows above and does not move the chances.
Wednesday 28 OctoberLow confidence this far out
No — 0.3mm of rain falling.
Limiting factor:grass wetness
good to go touch and go dark, frost or snow already goneFainter means fewer forecast runs agree.
Growth
How fast it is growing, and when it will need cutting again.
15%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 11°C.
- Over the next 10 days
- about 5mm 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 AL2, Hertsmere
12.8°C55°F
at 6cm — germination depth
Seeding conditions are open — soil is 12.8°C at 6cm and holding above 9°C.
Warming over the next 10 days.
Cross-checks against an independent estimate from air temperature (10.7°C), which agrees to within 0.0°C.
Almost every UK and Irish lawn is a ryegrass and fescue mix, whether it was sown or turfed. We assume that, and use 9°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.
| Species | Soil needed | Days to sprout |
|---|---|---|
| Perennial ryegrasslikely yours | 8°C | 5–10 |
| Red / chewings fescuelikely yours | 8–10°C | 10–14 |
| Tall fescue | 10–12°C | 10–14 |
| Browntop bentColonial bentgrass | 10–12°C | 14–21 |
| Smooth-stalked meadow grassKentucky bluegrass | 12–13°C | 14–28 |
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.
AL2, Hertsmere in detail
Soil temperature in AL2, Hertsmere is currently 12.8°C at 6cm, and barely moving. 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 perennial ryegrass with fescue, which is what most lawns round here are sown with. That blend needs the soil to hold above 9°C before seed germinates reliably. Seeding conditions are open — soil is 12.8°C at 6cm and holding above 9°C.
1 of the next 10 days look workable. The other 9 are held back by wet grass or soft ground. As for the weekend: nothing doing. Nothing to cut — the grass is barely growing (growth potential 0.07). Conditions themselves are fine. And nothing else in the next 10 days either.
Nothing in the current forecast for AL2 opens a sensible window. The ground reads as firm after 5mm rain over the last week, medium (loam) soil, and that is usually what decides it at this time of year.
Save this lawn and we will email you when the windows open.
We already send you the forecast email? Use the same address.
Single-model forecast here — no ensemble covers this location, so there are no odds to show. Forecast from Open-Meteo, refreshed through the day. Soil temperature is modelled, not measured — how that works and where the thresholds come from.