Eagle Ops Scheduler

What it is

Cool-season turf — bentgrass, fescue, poa annua, perennial ryegrass — tolerates close mowing on UK and Ireland courses. There is no single BIGGA-published "recommended" cutting height table: BIGGA's editorial framing is that heights are "relative to different courses" and that supes "can probably justify why they use the heights of cut they do" [bigga:2024-rough]. What BIGGA does publish are concrete examples from named course managers, summarised below.

Greens — summer, BIGGA-published examples

Alwoodley (Steve Carroll, 2019): "we cut at 3.5mm" through summer [bigga:carroll-2019].
Gaudet Luce (Andrew Laing, 2025 interview): summer minimum 3.75mm [bigga:2025-greens].
Formby Ladies (Rob Sandilands, 2025 interview): summer "around 4.5mm" [bigga:2025-greens].

For tournament setup at the close-cut end: Royal Portrush cut greens at 3.75mm for the opening three days of the 148th Open Championship (Graeme Beatt, 2019) [bigga:beatt-2019].

Greens — winter, BIGGA-published examples

UK supes consistently raise green heights for winter:

Bonar Bridge and Ardgay (Caroline Munro): "up at 5mm" in winter, "never go lower than 4mm" year-round [bigga:2025-greens].
Gaudet Luce (Laing): winter 4.5mm [bigga:2025-greens].
Formby Ladies (Sandilands): winter 5–5.5mm [bigga:2025-greens].

The lift is typically ~0.5–1.5mm above the summer height — easing turf stress through the low-growth months.

Tees and fairways — published examples

From Carroll's 2019 piece on Alwoodley (Leeds heathland, summer):

Tees: "8mm through the summer" [bigga:carroll-2019].
Fairways: "14mm" [bigga:carroll-2019].

These are single data points; other UK courses will differ.

Rough

Deliberately not numeric. BIGGA's 2024 editorial position is that rough length is course-relative and resource-dependent, not a published target [bigga:2024-rough]. A future entry on rough-management should cover regional, ecological, and pace-of-play considerations.

Why it varies

Course type (heathland vs links vs parkland), season (winter raise is universal across the 2025 interviews), turf species composition, and tournament calendar. The 2025 greens-secrets interviews [bigga:2025-greens] all describe a winter raise of 0.5–1.5mm above the summer height to protect the plant.

Cultural-first context — fungicide loss as a height-of-cut driver

The same 2025 greens-secrets panel surfaces a quieter pressure on cutting-height discipline: UK supes increasingly cannot rely on fungicidal intervention to compensate for stress-inducing close cuts, because the chemistry has been withdrawn. The operational consequence shows up in why heights are raised, not just what they are. Three representative framings from the panel [bigga:2025-greens]:

Andrew Laing (Gaudet Luce): "One of the biggest challenges for us is the lack of chemicals available compared to what we've been used to in years gone by and I think lots of clubs are having to change their processes to accommodate that."
Caroline Munro (Bonar Bridge and Ardgay): describes a near-zero- fungicide programme — "I have – once in the 15 years I've been here – sprayed a fungicide, but that's it" — sustained operationally by a combination of free-sand topdressing and a year-round HOC floor of 4mm (i.e. she refuses to chase the close-cut speeds that would force her hand toward fungicide).
Rob Sandilands (Formby Ladies): flags the strategic dimension explicitly: "If you've not managed to communicate that, or get some strategies and policies in place that are starting to mitigate them [the chemistry losses], you're going to be in a lot of trouble."

The pattern is consistent: fungicide-loss raises the cost of a too-close cut (a stressed plant cannot be rescued chemically the way it once could), so the operational HOC floor drifts upward and the winter raise is held longer into shoulder seasons. This is the cultural-first management footprint at the cutting-height layer; it is the same pressure documented in the dollar-spot context (see dollar-spot-management §"Fungicide-resistance discipline"), but reaches the supe before any disease appears — as a quiet floor on how low they're willing to cut.

Autumn-cooling HOC risk — the 3.5mm threshold

Noel MacKenzie (Director, Sports Turf Consulting; 4,000+ advisory visits since 1993) frames the autumn-specific version of the close-cut risk explicitly [bigga:2024-mackenzie-autumn]: "There have been instances where greens have been mowed at 3.5mm or lower and everything's ticking along just about OK, but then the weather flips a few degrees, the disease comes in and absolutely poleaxes the course so the turf never achieves a sound winter condition."

Operational read: 3.5mm is a soft floor for sustained autumn HOC, not a hard one. The threshold is honest about the failure mode — it's not "below 3.5mm always damages turf"; it's "at-or-below 3.5mm leaves the surface with no resilience reserve when the weather shifts and autumn disease arrives, and the turf will not recover its winter baseline before the cold sets in." The risk is asymmetric: the supe gets daily-play upside for as long as conditions hold, but the downside (poleaxed course → blown winter recovery → spring catch-up problem) compounds across seasons.

MacKenzie pairs this with the autumn disease-pressure framing [bigga:2024-mackenzie-autumn]: "Disease pressure is a year-round issue but it becomes more acute as grass growth slows… Whenever it's mild, humid and moist, but not super wet, that's when the threat of fusarium patch is at its greatest, and problems can arise from thatch fungus, leaf spot and anthracnose disease." The four-disease autumn cluster (fusarium / thatch fungus / leaf spot / anthracnose) operationally activates the 3.5mm floor — close-cut autumn surface + mild/humid window = the trigger conditions.

This pairs with microdochium-snow-mould on the disease side and with the §"Cultural-first context" above on the chemistry-loss side: the same 3.5mm-or-lower autumn surface that historically would have been rescued by curative fungicide is now running without that rescue option (per Stuart Green / BIGGA's withdrawn-actives reference — see withdrawn-actives-uk-reference). The compound effect is that the autumn-HOC discipline is tighter now than it was a decade ago, not looser.

When to deviate

The supe's configured per-zone mowing-height standard always overrides this entry. Reasons to ease toward higher (longer):

Heat / drought / disease stress windows
Major aeration or topdressing recovery
Specific membership or design context (links vs parkland)

green-speed-stimpmeter — mowing height is the primary lever on speed; consistency-over-Stimp doctrine surfaces there
green-firmness-measurement — height interacts with thatch and firmness
championship-greens-prep-belfry — Belfry's 3mm summer / 4mm winter as a single championship case-study anchor for the same numerics
dollar-spot-management — the most prominent fungicide-loss disease pressure currently driving the cultural-first HOC floor
withdrawn-actives-uk-reference — the underlying chemistry-loss inventory behind the cultural-first HOC floor (Iprodione / Carbendazim / Chlorpyrifos / Imidacloprid withdrawals + named cultural alternatives)
topdressing-rates-uk-greens — paired with cutting height for surface quality; named-club annual tonnage anchors
fungicide-resistance-management-uk — chemistry-side companion to §"Cultural-first context"; the FRAC-rotation discipline is what preserves the actives that aren't withdrawn, and the cultural HOC-floor pressure documented here is partly designed to reduce the number of fungicide applications per season (i.e. fewer selection-pressure events for resistance to develop)

Cool-Season Cutting Heights (UK Examples)