Sustainability has also come to the fore, with greenkeepers now limited in their input selection. As expected, maintaining a golf course for performance and sustainability requires routine maintenance and renovation throughout the year.
Contents
- Golf grass species: Links courses vs parkland courses
- Choosing the best golf green grass seed
- Golf green maintenance
- Overseeding greens
- Golf greens fertilising
- Golf tee maintenance
- Overseeding golf tees
- Fraise Mowing: ‘Koroing’ tees
- Fertilising golf tees
- Golf course fairway maintenance
- Advice for overseeding golf course fairways
- Golf fairway nutrition
Golf grass species: Links courses vs parkland courses
UK golf courses can be categorised as links or parkland. While links courses have been sculpted into coastal dunes, parkland courses are found inland, often near woods and meadows.
The UK’s oldest golf courses are typically links, leveraging the naturally wild coastal landscape, whereas heavy-duty construction is needed to develop parkland courses. Nevertheless, many parkland courses are now over a century old.
Links grass varieties
With naturally sandy soils, links courses usually have high fescue populations on greens, tees, and fairways. However, browntop bentgrasses (Agrostis capillaris) can be managed on links greens. Meanwhile, perennial ryegrasses (Lolium perenne) can be suitable for walkways and tees.
Where ryegrasses are used, Germinal recommends ultrafine varieties like Cabrio, which look like fescue. This is not possible with other perennial ryegrasses and is a triumph of golf grass breeding.
Parkland grass varieties
Greenkeepers can be more diverse on parkland courses, managing perennial ryegrasses on tees, browntop bents or creeping bentgrasses (Agrostis stolonifera) on greens, and a perennial ryegrass and fescue mixture on fairways. These courses often have heavier soils and it is difficult for fescue to persist through a wet winter.
On parkland courses, there is a trend of cutting down to 3mm, sometimes lower. This makes bentgrasses essential because fescues do not persist below 4-5mm.
For this reason, Germinal has driven the uptake of modern creeping bent varieties among UK greenkeepers. When used in a mixture, creeping bents are often paired with the ubiquitous browntop bents.
This shift stems from modern creeping bent varieties tolerating extremely low golf green mowing heights and offering vigorous lateral growth. Modern creeping bents are also ideal for sustainable golf course maintenance because they rely on fewer inputs, especially water and nitrogen fertiliser.
Ultimately, creeping bentgrass can be managed alongside browntop bent with lower water and N input levels that do not favour Poa annua, which is much more vulnerable to disease and drought.
Choosing the best golf green grass seed
While fescue and bentgrass can produce a great playing surface, it can be extremely challenging to establish seed mixtures with both species included. This is because of their differing sizes, with fescues needing a 2-5mm sowing depth and 10-12mm for bentgrasses to achieve uniform germination. If one species fails to establish, it can make sense to only that species.
More recently, greenkeepers are opting to sow 100% bentgrass mixtures on parkland courses where a 3-4mm golf green mowing height is essential. This ensures the bentgrass seed is sown at the correct 2-4mm depth, giving a better chance of establishment.
Where you have fescue golf greens, you can overseed with a 100% fescue mixture to maximise this species. In this case, Germinal can recommend the A27 All Fescue mixture.
To outcompete Poa annua and achieve disease-free greens, bentgrass is the answer. Here are three highly effective options.
| Golf green grass seed mixtures | Species | Varieties | Key features |
| Tour Leader | Creeping bent |
Tour Pro (GDE) [50%] 007 (DSB) [50%] |
Disease resistance 3mm mowing height Drought tolerant Sustainable inputs |
| AberMajesty | Browntop bent |
AberRegal [20%] AberRoyal [35%] Musket [45%] |
Fusarium resistance Excellent shoot density Fine-leaved |
| ForeFront Greens |
Creeping bent Browntop bent |
AberRegal [15%] AberRoyal [20%] Musket [25%] Tour Pro (GDE) [20%] 007 (DSB) [20%] |
Soil- or sand-based greens Disease resistance Stress resistance Year-round colour Excellent shoot density Fine-leaved |
Tour Leader is a particular standout, pairing the UK’s top-rated creeping bentgrass, Tour Pro (GDE), with the highly regarded 007 DSB. Offering the best of both, these varieties offer high shoot density and prorate growth alongside sustainable fertiliser and water requirements. This helps to address the traditional challenges of golf course upkeep.
Golf green maintenance
While courses known for smooth, fine, even-textured putting surfaces can be forgiven for failings in other areas, those with great fairways and poor green will not.
Golf green maintenance aims to maintain a level, playable, disease-free putting surface. This is achieved by managing desirable, disease-resistant grass species such as fescues or bentgrasses and outcompeting Poa annua. When curative fungicides were widely available, Poa annua greens were manageable, but not anymore.
Proactive Seeding
The loss of curative fungicides has rendered Poa annua virtually unusable and it must be outcompeted in greens. To achieve this, Proactive Seeding is Germinal’s recommended golf green maintenance strategy.
If you are serious about outcompeting Poa annua, you need to be Proactive Seeding. This entails overseeding three or more times a year with bentgrass or fescue varieties. This should be seen as routine golf course maintenance. Staking everything on one major renovation and expecting the plants to establish is risky.
Switching/brushing
Allowing dew to sit on grass blades is one of the main ways for diseases like fusarium to spread across a green if temperatures are conducive. This must be removed and can be done by switching, where dew is knocked off the grass with a long cane or with a tractor-mounted brush.
Drainage
Good drainage is vital for greens and consists of well-laid clay tiles, or plastic pipes, usually placed in a herringbone pattern in trenches with adequate falls conforming to a recognised design.
The trenches should be backfilled with an approved gravel or stone carpet to a depth of 100mm and a binding layer of sand to a depth of 50mm spread evenly over the stone. Lastly, a good root zone mix that has been laboratory tested should be applied to 250-300mm depth and a good fine tilth achieved.
Thatch control
The accumulation of thatch on golf greens must be avoided as this can quickly build up over a season to create a soft spongy surface.
Thatch can negatively impact both drainage and irrigation. This fibre will retain moisture, leaving a soft surface susceptible to fungal disease. When dry, the fibre acts as a water repellent hindering the penetration of moisture to the soil. Under these conditions, grasses such as annual meadow grass will colonise weaker areas when moisture becomes available.
Where there are serious problems of deep thatch, this should be tackled before any golf green overseeding programme starts. Deep coring or verti-cutting followed by topdressing with coarse grain sand is required to punch through and remove the thatch layer and improve the structure of the underlying soil over time. This should be combined with regular, light scarification throughout the year.
Continue until achieving the desired minimum of 1-2mm thatch. For this to be assessed properly, accurate records can be kept with the thatch content measured at the beginning of the campaign and measurements taken and recorded on a regular (quarterly) basis to monitor progress.
Aeration
Soil compaction and the loss of porosity deprive the vital rootzone area of oxygen and moisture. This causes grasses to die back, leaving thin or bare areas on greens and tees. Machinery can effectively spike the surface by hollow coring, slitting, or solid tines.
Slitting tines break up surface thatch, restoring moisture and air to the soil. Where there is serious compaction on greens, the greatest effect will likely be achieved by hollow tining to a depth of at least 100mm. There are several more spikers on the market that will give an even greater penetration of up to 225mm. The hole should be filled in with sand of a uniform rounded profile or a good open compost to improve the soil.
Top dressing greens
All fine turf areas benefit from a top dressing to preserve a true and level putting surface and reduce thatch build. An application of 2kg/m² can be applied two or three times a year in summer, though it is important on thin swards not to smother the grasses otherwise dieback will occur.
The type of top dressing applied will depend on the original rootzone mixture as a similar material should be used to maintain a continuity of profile.
On well-established golf courses where greens are built on local soil, coarse-grained sand will likely be the best top dressing to improve soil structure – particularly when applied after hollow coring.
Selection-wise, the crucial aspect of top dressing greens is that the sand is coarse-grained, not silty, and that consistency is maintained.
Overseeding greens
Timing
Autumn is not the only time for overseeding greens. A Proactive Seeding programme requires regular overseeding that can be done in spring, summer, or even winter as cold-seeding.
When comparing the benefits of seasonal overseeding, results should be measured. Survey the number of seedlings that mature into healthy plants rather than the percentage of germination and seedling numbers.
For example, you could overseed greens in September but are seeing high seedling mortality due to playing pressure despite successful germination. Alternatively, consider overseeding greens in early spring.
Despite seeing fewer seedlings, less playing pressure and increased cutting heights will allow more of them to establish healthy hardened plants ahead of the main playing season. Comparatively, you could be better off overseeding greens in spring.
This approach is supported by research from Germinal Horizon, which found that plant counts for bentgrass sown via cold-seeding steadily increased over several weeks following emergence after 24 days.
Application
Evaluate thatch levels, irrigation coverage, wear patterns, drip lines, tree roots and every other possible biotic cause impacting grass performance on greens. Once completed, you can proceed with the preparation.
There is no right or wrong way to create the correct environment for germination. Broadcasting or drop seeding into linear grooves, hollow cores, or tine holes can all work. And, of course, there are many good seed drills available.
The crucial element is to ensure good seed-to-soil contact. Seed must also be sown at the correct depth for the species and that it remains adequately and consistently moist.
Bentgrass should be sown at 2-5mm and fescues at 10mm. If overseeding greens after surface disruption such as hollow coring, it is essential that cores are top-dressed to within the correct depth to the surface before either top-dressing or broadcasting seed and then applying a light top dressing to level the surface.
A grass seed only has a small store of energy for the emerging plant to use during germination. The coleoptile, therefore, needs to be able to push through the soil surface as quickly as possible so that the first leaf can emerge and begin photosynthesising. The seedling can then start processing its own energy and will be more likely to establish strongly.
Watering
Following overseeding best practices, germination can happen in just seven days, but 14 to 21 is more likely. During this period irrigation is the only controllable resource you have. Ideally, the surface should be permanently damp and as soon as the surface feels dry and no material particles stick to your hand, cover it with a light sprinkling of water.
Establishment
When seedlings start to appear and the sward is forming, watering should become less frequent but heavier. The grass sward should be allowed to dry between applications to prevent damping off.
At first cut, it helps to raise the cutting height – ideally 6mm. However, if playing commitments restrict you to an increase of 1mm from your current golf green mowing height for a week, this would be the next best scenario.
If overseeding greens into summer cutting heights, then consider sowing creeping bentgrass greens. This species is the most adaptable to taking close mowing straightaway.
Consideration must be given to the establishment of seedlings. Aggressive sward management must be avoided during this time. Sensible grooming with brushing and light rolling, and only light aeration if essential, should be undertaken as core golf course maintenance techniques.
Golf greens fertilising
The amount of fertiliser needed for greens will be determined largely by the soil type – for example, USGA sand-based vs traditional push types.
Species composition will also have an influence but avoid trying to manage perennial ryegrass on greens, which Germinal would advocate against. The matter of species composition largely comes down to whether you are trying to sustain Poa annua or pushing towards a species conversion.
Germinal recommends species conversion via Proactive Seeding as essential following the loss of curative fungicides to manage disease control in Poa annua greens.
On parkland greens where browntop and creeping bents are being increased, Germinal often finds that successful greenkeepers are managing on 75-110kg N/ha each year. This is generally trickle-fed with liquids often utilised.
This level of N is enough to sustain the desirable grasses and keep the Poa annua lean to its detriment, thus helping the desirable species win that battle. The exact levels and ‘how far you can push things’ against Poa annua are for individual judgement.
With modern creeping bent varieties such as Tour Pro (GDE) and 007 DSB, their lateral growth can support sustainable golf course maintenance by requiring lower nitrogen inputs than older varieties like Penncross or SR1119. That makes these varieties ideal for punching into Poa annua and start outcompeting while it is not being fed.
Ultimately, grass selection is fundamental to golf course maintenance and Germinal Amenity can recommend high-performance mixtures with varieties that are proven to perform on the 2024 Turfgrass Seed Guide from BSPB.
Golf tee maintenance
Regular scarification and aeration are fundamental to effective golf tee maintenance, but so is fertiliser application in summer to ensure strong growth.
Selecting the right golf tee grass seed
Compared with the greens, the obvious difference with tees is the need for regular divoting to restore the playing surface and reintroduce desirable grasses. When it comes to golf tee grass seed, we typically recommend fescues for links courses and perennial ryegrass for parkland courses.
While fescue has long been desirable in tees mixtures to soften the appearance and give some binding capacity to the turf, breeding advancements of ultrafine varieties found in A5 have made perennial ryegrass the go-to for many greenkeepers.
Suitable for parkland and even some links courses, our A5 mixture offers quick establishment, superior rooting, high-density ground cover, and a hard-wearing playing surface.
Mowing
Ultrafine perennial ryegrass varieties blend well with fescues and can even be mown down to 6mm. This lets you benefit from the wear tolerance of ryegrass and its fast germination time, even at low temperatures, to maintain grass cover and repair divots quickly.
Mowing at 10mm will give tees an ideal height for maintaining ryegrass or fescues. As mentioned, there is a trend of mowing down to 6mm but this will place them under more stress. At 6mm, creeping bentgrass can be considered, with Germinal’s A8 ultrafine mixture working well.
Aeration
As with greens, soil compaction and loss of porosity lead to a lack of oxygen and moisture in the root zone of tees. The grass will then die back to leave thin or bare patches. To remedy, aerate by spiking the surface via follow coring, slitting, or solid tines – this is effective when the ground is hard and difficult to penetrate.
Slitting tines break up the surface thatch while restoring air and moisture to the soil. If there is serious compaction at a tee, the best approach is to hollow tine to at least 100mm. But you can go deeper if you have a spiker that can penetrate to 225mm. After, fill with sand of a uniform rounded profile a good open compost to ameliorate the soil.
Overseeding golf tees
You can broadcast or drop-seed into linear grooves, hollow cores, or tine holes, with good seed drills available. When broadcasting after hollow coring or aeration, make sure to top dress to the correct depth before applying golf tee grass seed.
Ensure good seed-to-soil contact and sow at the correct depth for sufficient and consistent moisture. Ryegrass and fescue mixtures for tees can be sown at 10mm.
Golf course maintenance can be applied to tees at any time when soil temperatures are at least 10°C and good germination can be expected. This will likely be from April to September in the UK.
Here is a summary of the golf tee overseeding process:
1. Scarify
2. Mow
3. Hollow tine or aerate – depth is determined by compaction level.
4. Overseed – use your overseeder in two directions. Otherwise, ensure seed is sown at the correct depth.
5. Light top dressing
Fraise Mowing: ‘Koroing’ tees
In recent years, Germinal has helped pioneer the use of machines like the Koro®Field Maker to remove most of the surface of tired old greens when reseeding. This replicates the process of many premier sports pitches but on a smaller scale.
Germinal has found that carrying this golf course maintenance out in autumn or early spring can rejuvenate tees and get them back into play by mid-spring or early summer.
This process has the potential to become routine for some courses. Two or three tees can be revived like this over a ten-year rolling programme. Here’s the process:
- Koro tee surface
- Vertidrain
- Fertiliser application (GSR Tri-Phase)
- Top dress level
- Overseed with seed drill
Depending upon prevailing weather, germination sheets might be helpful after sowing. We have seen accelerated opening times on courses that have used sheets when faced with cold weather. Quicker establishment has also delivered the proven benefits of cleaner, more uniform tees.
Fertilising golf tees
Tees can receive more wear than the rest of the course. For strong recovery and rapid establishment of seed in a divot mixture, a slow-release fertiliser application is recommended in spring.
GSR Tri-Phase is perfect to apply in March and feed tees during the initial growing period. On sand-based tees with perennial ryegrass swards, a second application can work well during the season. Alternatively, the base feed can be topped up with lower nitrogen slow-release granular feeds like Novatec Classic or liquid feeds.
For sustainable golf course maintenance, Germinal advises against quick-release due to their cold-water solubility. This makes them less efficient than slow-release granular fertilisers and they release more nitrous oxide into the atmosphere.
Your nutrition programme will be influenced by your soil type, grass species, and the prevailing weather in any year. The exact applications should be determined by your assessments of each tee at any given time. As a range, you could typically apply from 80-120kg N/ha each year.
Golf course fairway maintenance
Scarification
In fairway maintenance, scarification is a routine but essential activity where removing dead plant material reduces thatch. Depriving soil of air, light, and water, thatch inhibits grass growth and harbours fungal diseases that can kill the sward.
While frequency will depend on the amount of thatch, monthly scarification is a reasonable target for fairway maintenance. This will help ensure desirable grass species prevail over weeds, leading to healthier and more playable fairways with less devoting needed.
Aeration
Arguably, this is the most important part of golf course fairway maintenance. Paired with scarification, aeration can actually reduce the need for scarification by encouraging desirable grasses to dominate the sward and reduce weed grasses such as Poa annua.
Aeration is also vital for relieving compaction by ensuring efficient filtration of water from the soil surface and maximising macropores within the soil profile. This facilitates air exchange so that roots can respire and grass plants are as healthy as possible. Healthy grass equates to hardwearing, aesthetically pleasing fairways.
Hollow tining or slitting should be practiced more frequently and work to create fissures and increase macropores with the top 250mm of the soil profile. While it is hard to overdo either activity, it is important to do so when conditions are correct.
To be effective, the soil profile needs to be moist enough to allow slits or tines to penetrate the soil but dry enough that the action of this process causes disturbance in the soil profile to create the fissures and pores you are aiming to make.
Aerating when it is too wet is wholly counterproductive. In general, subject to suitable weather, fairway aeration could be carried out five to six times usually between September and March.
Top dressing fairways
In golf course maintenance, top dressing fairways keeps the surface firm, controls thatch buildup, and aids drainage in the aerated soil structure. Aiming for top dressing with sand supported by aeration is the ideal fairway maintenance strategy.
Advice for overseeding golf course fairways
Budget, time, and resources can all make overseeding fairways an aspiration rather than a reality in golf course maintenance programmes. Fortunately, with the innovation of specialist overseeding drills, it is now more efficient than ever to stitch in beneficial fairway grass seed.
As with greens and tees, managing a higher proportion of desirable grasses makes for stronger, more stress-resistant fairways that play better and look better.
In recent dry summers, fairways have been exposed. Those dominated by shallow-rooted weed grasses died back and didn’t recover, resulting in forced fairway overseeding on many courses.
If even a proportion of fairways could be overseeded on a rotational basis, this would increase the resilience of those fairways in times of stress. Yes, they will still go dormant and brown, but they will return better than fairways dominated by weaker weed grasses.
When maintaining a golf course, overseeding of fairways at 20g/m² should take place after scarification and aeration. A blend of fescues, fescue and ryegrass, or 100% ryegrass can be used depending on the existing make-up of your fairways and your mixture preference.
| Fairway grass seed mixtures | Species | Key features |
| A34 Fescue Fairways and Surrounds | Fescue |
Great appearance Disease and drought tolerance Good for divoting |
| A28 Ultrafine Ryegolf |
Fescue Perennial ryegrass |
Versatile Tolerates close mowing Hard-wearing |
| A5 Cricket, Tennis, and Tees | Perennial ryegrass |
Fine-leaved Quick to establish Hard-wearing High-density ground cover Superior rooting |
As the UK climate trends towards drier, hotter spells in summer, species of grass that were once niche on courses could become more commonplace. Going forward, blends of an appropriate fine-leaved tall fescue and perennial ryegrass may be utilised to instil resilience into fairways, especially in the south.
Golf fairway nutrition
One or two applications of slow- or controlled-release fertilisers are recommended throughout the year. As with tees, the exact amount of nutrition required is determined by soil type, species managed, and prevailing weather conditions.
An application of GRS Tri-Phase or Novatec Premium is recommended in most cases in March or April. Generally, most fairways are suited to a range of 40-80kg N/ha each year.
Expert grass advice
There is a lot that goes into golf course maintenance. Contact Germinal today if you want to talk about selecting the right mixtures for your greens, tees, and fairways.