There comes a point in every long-running problem where the evidence becomes too obvious to ignore. For many of the bowling clubs that get in touch to ask about solving green performance problems, I think they are now at that point with sand.
With another summer of high heat, dry patch, weak turf, hydrophobic soil, disease pressure, uneven surfaces, irrigation limitations and increasing renovation costs, the question can no longer be: “What top dressing are we putting on this autumn?”
The question needs to change to:
“Why are we still adding more sand to a green that is already suffering from too much sand?”
Over the last 16 years at Bowls Central I have dealt with hundreds of UK bowling clubs, and the recurring pattern is hard to miss. The greens that are suffering most from Localised Dry Patch, poor recovery, weak rooting, inconsistent surfaces, excessive thatch, winter disease problems and summer drought stress are invariably the same greens that have been dressed routinely with sand-based materials for decades regardless of the underlying soil texture.
This process is repeated annually in many cases just because it is what the club has always done. Maybe because somebody once said top dressing was essential, or that the green looks a lot better right after the autumn work is completed. The work might well have been essential at some stage, but in many cases it has been repeated 30, 40 or even 50 times. How many more goes on this roundabout are left before the green is beyond redemption?
I know a top dressing operation feels like proper greenkeeping and that a big dramatic autumn programme makes it seem like we are doing the right thing, but it’s only the right thing if it improves playing conditions over the longer term. The trouble is that the green can look like it’s had a good renovation and still be agronomically worse off than it was before the programme was completed.
A layer of sand brushed over a weak, thatchy, dry, hydrophobic surface may look like progress for a few weeks. It may even pacify the committee or the club’s elite players for a while, but if the rootzone is already too sandy, these dramatic end of season programmes, often ordered from a contractor’s Gold, Silver or Bronze list of standard renovation programmes, will in many cases move the underlying condition of the soil and turf deeper into the problems the green already has.
This blind repetition is how many clubs arrive at the point where they feel they need to rebuild the green.
The 50/50 Comfort Blanket
One of the most common objections I hear to my uncomfortable views is this:
“We’re not using straight sand. We’re using a 50/50 sand and soil mix.”
I understand why that sounds reassuring. It sounds moderate, sensible even and that the club has moved away from the extreme and chosen something more “soily”. But the name of the material is not the important bit. The Particle Size Distribution dictates what the material being applied actually is and I explained this in some depth in the first article in this series.
Feel free to go back and review that at your leisure, but for a quick re-cap before we move on, it goes something like this: A so-called 50/50 top dressing can still be practically pure sand. For example, I recently looked at a well-known supplier’s 50/50 dressing, and the clay and silt content was only 0.2%, with 0.4% gravel also in the mix. That means that the remainder of the mineral content was, you guessed it, sand. In real terms, the material was 99.4% sand as supplied, and if the gravel was removed from the calculation, the fine earth (mineral) fraction was roughly 99.8% sand.
This is where clubs get caught out. They hear the word soil and imagine something brown, living, moisture-retentive and fertile. But soil itself can be mostly sand. The soil element in a dressing mix does not automatically mean loam, humus, clay, silt, nutrient exchange, microbial life or drought resilience is being added.
It may simply mean more sand, with a better label. This is why “50/50”, “70/30”, “60/40” are not good enough descriptions for a club trying to make serious decisions about the future of its green. These names might be convenient for ordering materials, but they do not tell you what the material will do once it is incorporated into the rootzone of your green.
Understanding Soil Texture
I have written several articles on soil texture over the years because I believe it is one of the most important subjects a bowling greenkeeper can understand. That might sound dry and technical, but it is not.
Soil texture is not an academic subject when your green is burning off in July, when expensive irrigation water sits on the surface in one place and disappears in another, or when the green is soft, wet and disease ridden in winter, then hard, dry and bumpy in summer.
It is not academic when seed fails to establish in the same dry patches year after year or when the club is suddenly talking about a rebuild costing tens of thousands of pounds. The physical make-up of the rootzone dictates the behaviour of the green. It influences drainage, moisture retention, nutrient availability, pH stability, rooting, microbial activity, disease susceptibility, surface consistency and ultimately playing performance.
That is why the Soil Texture Triangle matters. It reminds us that soil is judged by the proportions of sand, silt and clay. It also reminds us how easily a bowling green can move into dangerous territory. A soil with 90% sand is classified as sand. Many clubs are now trying to manage greens that have effectively have sand rootzones because of decades of routine top dressing.
And once a green reaches that point, adding more sand is not a neutral act. It pushes the green further in the same direction and in that direction lies poor nutrient retention, less biological resilience, more irrigation, wetting agent and fertiliser requirement. It leads to emergency repairs of damaged and dying turf, more committee anxiety about cancelled matches or being dropped as the venue for important county events, and inevitably leads to talk about rebuilding the green at huge expense.
The irony is that many clubs are still using sand top dressing to try to solve problems that sand has helped to create.
The Rebuild Trap
In the last week or so, I have heard of two clubs whose greens are now scheduled for complete rebuilds because of problems associated with dry patch, weak surfaces and long-term rootzone dysfunction.
I am not going to comment on those specific greens here because every case needs proper diagnosis, but the general pattern should make every club pause. A rebuild is often treated as the final, decisive solution. Scrape off the top couple of inches, rotovate, relay, seed or turf, and start again.
That sounds clean and conclusive. But Localised Dry Patch and hydrophobic soil problems are rarely that polite.
If the underlying rootzone is still sand-dominated, inert, biologically weak and full of old water-repellent organic residues, then simply disturbing and relaying the surface may not remove the problem. In some cases it may only reset the clock. The dry patch can sit there, waiting for the next period of heat and drought to bring it back into view.
This is why a proper, relatively non-invasive renovation programme will always make more sense, agronomically and certainly financially
And it is why a proper and urgent conversation about renovation matters before the club gets caught up in any discussion about re-building the green. Because the cheapest rebuild is the one you never need. A club can spend many tens of thousands of pounds rebuilding a green, lose a season or two due to re-establishment and still end up with a green that has all of the same old problems as before. Or it can start spending its normal renovation budget more intelligently now. That is the autumn opportunity and thre time to plan for it is now.
The Cost of the Sand Habit
The financial side of this is often overlooked because top dressing is seen as a normal annual cost. But let’s look at it plainly.
Five tonnes of 70/30 dressing can easily cost a club more than £1,000 before VAT, labour, machinery, aeration, scarification, brushing-in, dragmatting, seed, fertiliser or follow-up work are even considered. For many clubs, the real cost of the traditional autumn dressing operation may be closer to £1,500 to £2,000 before VAT once everything is included.
And what has the club bought? If the material is still close to 99% sand, the club may have spent a substantial chunk of its autumn budget adding more of the same material that has already pushed the green towards its present condition, essentially funding a continuation of the same old problems that currently beset the green.
The top dressing invoice is only the beginning. The real cost comes later, in more dry patch, more irrigation dependency, weak recovery, increased thatch problems, increased fertiliser requirement to get a response from a hungry rootzone, more disappointment when expensive new seedlings dry out and wilt, and eventually the troublesome conversation about reconstruction of the green.
If a club has £1,500 or £2,000 available for another traditional autumn dressing operation, then it has the money to start changing the condition of the green for the better. It’s not a matter of whether or not the club can afford to do something different. The question is, can we afford not to?
This Autumn’s Chance
Autumn renovation is the best opportunity most clubs will get to break the sand cycle without causing panic. That is because the mechanical work involved in a proper renovation programme already creates the ideal route into the rootzone for new, restorative materials.
Heavy-duty scarification opens grooves through the surface, removes accumulated organic material, thins out weak growth and, very importantly, can bring a surprising amount of previous top dressing and rootzone material back up to the surface, where it can be utilised as part of what we can call a not dressing programme. Hollow tining then opens the profile further, removes cores, brings more of the previously purchased material to the surface where it can be separated from the thatch, introduces oxygen and creates a network of holes where a more useful material can be incorporated to ameliorate the sand.
Traditionally, this is the point where many clubs order and apply more sand, but this is exactly the point where I think the decision has to change. Instead of importing another 5 tonnes of sand-based dressing, use the mechanical work to recycle and redistribute the material already on and in the green, and to facilitate the introduction of natural, functional soil-building materials into the grooves and holes with it.
The green will still be renovated, it will still look like it’s been top-dressed, because it will have been. The surface will still have material worked into it. The committee will still see that something useful has been done, but the crucial difference is this:
No new sand will have been added. Instead of adding more inert mineral material, the club will have used the renovation window to add carbon, humus, biology, rooting support and nutrient-holding function directly into the spaces created by the work.
That is a very different kind of renovation. It looks familiar from above, but underneath, it is heading in a very much more positive direction.
The Big Gulp of Oxygen
One of the most powerful parts of this operation is also one of the least visible…Oxygen.
A sand-dominated, thatchy, hydrophobic, compacted and layered rootzone can become a miserable place for roots and microbes. Water movement becomes uneven. Air movement becomes restricted. Organic material does not break down properly and adds to the thatch layer. The green becomes wet and sour in one season, dry and water-repellent in another.
Heavy scarification and hollow tining are not just mechanical tidying operations. They are a chance to let the green breathe. They open the surface. They remove accumulated un-decomposed organic material previously destined to add to the thatch layer and previously applied top-dressings are dragged out onto the surface where they can be usefully mixed with good, healthy soil building supplements and worked back into the surface without adding ever more sand. They create channels. They allow gas exchange, where anaerobic soil gasses are exchanged for oxygen and the soil is immediately sweetened and low pH problems are solved almost immediately. They encourage deeper rooting and increased root mass. They make room for more and better aerobic soil biology. They give rain a better chance of entering the profile rather than sitting, running, ponding or immediately running out of the drains before any has been captured in the soil for the plants.
This is why autumn renovation should never be reduced to putting the green to bed. That doesn’t capture the usefulness of the operations. The real opportunity is to open the patient up, remove some of the trouble, get oxygen into the system and then place the right materials into the profile while the doors are open.
But what materials should you be adding?
Humigranule: Putting Humus Function Back Into Sand
Sand has very little ability to hold nutrients or moisture. It doesn’t provide much in the way of cation exchange capacity, and it does very little to support microbial activity in the soil. A living soil needs Humus to support the proper functioning of the soil and turf eco system. So in this renovation programme, we add one or two materials you might not be familiar with and these are BioActive Humigranule and BioActive RZ.
Humigranule is a granular humic material designed to help counteract the problems caused by excess sand in bowling green rootzones. It brings humus-like function into a profile that is often short of carbon and therefore microbial energy. It contains humic and fulvic acids and is designed to support soil structure, nutrient exchange, microbial activity, root development, stress tolerance and seed germination. It stays in the soil for the long term and becomes part of the support system for a properly functioning soil/turf eco system. After a while you will start to see this appear on your soil analysis as Organic Matter (Humus), something that is critically low in many high sand rootzones. Some experts will try to conflate the term Organic Matter with thatch and convince you that it is a bad thing, but the two couldn’t be more different
In simple terms, Humigranule helps make a sandy rootzone behave less like a bucket of inert mineral particles and a little more like a soil. That distinction matters. A typical autumn target of 10 to 15 bags of Humigranule after heavy mechanical renovation goes a long way towards rebuilding the missing carbon and humic function into the part of the profile where the grass roots need to live. By working it into the scarification grooves and tine holes it can get to work to rebuild a living soil that supports new seedlings after oversowing and the development of rootmass, all the time mixing with and ameliorating the old sand-dominated rootzone that now needs to be persuaded back towards life.
BioActive RZ: Biology Where Roots Need It
If Humigranule is about restoring humus function, BioActive RZ is about re-charging the rooting zone’s biology. This is the second part of the power combination you can apply instead of more sand.
BioActive RZ is a rootzone improver built around beneficial microbes, mycorrhizal fungi, humic and fulvic acids, trace minerals and a carefully graded carrier designed to help retain moisture and nutrients in the soil.
The fine perennial grasses do not work alone. In a healthy soil, roots operate in partnership with microbes, fungi, organic compounds, mineral exchange sites, moisture films adhering to soil particles and air spaces. In a dead, dry, sand-dominated rootzone, that partnership is weak. The plant is left trying to survive in a poor economy, with little reserve and little support.
BioActive RZ is designed to improve that rootzone economy. The mycorrhizal element is particularly important because these fungi form a symbiotic relationship with perennial turfgrass roots and help the plant explore a much greater volume of rootzone than roots can reach unaided. That matters in a sandy green where water and nutrients are often present unevenly, briefly or just out of reach.
The autumn timing is ideal because the green is being opened mechanically. Holes and grooves are created, but play isn’t disrupted. Seed is being introduced. Roots are active. Moisture is returning. Soil temperatures are still usefully warm for good solid recovery. Winter rain is on the way. There is a window to get beneficial material into the profile rather than leaving it sitting on top.
A target of 6 to 10 bags of BioActive RZ after hollow tining makes sense because the aim is to place it right in the rootzone, where it can get working right away.
The Elephant in the Room…LDP
The old autumn model was often quite simple. Scarify, hollow tine, add sand, seed, fertilise, hope. In other words put the green to bed and hope that it all works out for the best next year. However, these days many of the greens that have driven right past the Peak Sand sign are riddled with Localised Dry Patch (LDP) and hoping for the best with that isn’t an option.
If Localised Dry Patch has been a problem, this is especially important. Hydrophobic soil does not fix itself because the calendar reaches September. The water-repellent material in the profile still needs oxygen, microbial activity, moisture movement and repeated re-wetting. Incorporating a granular wetting agent during renovation gives winter rainfall a much better chance of entering and rehydrating the profile instead of simply sitting on top or moving unevenly through old pathways.
This is one of the most underused opportunities in bowling green maintenance. Winter rain is free, but only if the soil can accept and use it. A granular wetting agent will remain active in the soil for months and help to utilise the winter rainfall to continue the recovery of LDP that you’ve been working on with Aquastasis and Yucca through the summer months
Overseeding
Autumn renovation is also the best chance many clubs have to improve grass species composition and to recover bare areas.
If the green has suffered through summer, if dry patch has thinned the sward, if Poa annua has dominated weak areas, if bare patches have appeared, then the autumn renovation window should not be wasted.
However, new seed needs a fair chance. Throwing good seed into a dry, inert, hydrophobic, sand-dominated profile and hoping for the best is poor economics. Seed needs soil contact, moisture, oxygen, nutrition and biological support. That is another reason why the Humigranule and RZ combination makes sense during renovation. It helps create a more favourable establishment zone at the exact moment the seed is being introduced.
The goal is not simply germination, but managed establishment. There is a difference. A seed can germinate and still fail if the aftercare and/or soil conditions aren’t right. For the first week or so after germination, grass seedlings exist solely on their seed case reserves, so it isn’t unusual to see 100% success at this stage. However, after the seed case reserve is used up the fragile seedlings are an on their own and need continued monitoring as even an hour or two in dry soil will cause them to wilt and die…you must ensure that there is enough soil moisture for them to have the best chance of survival.
A renovation programme should be judged not by whether green shoots appear, but by whether the new grasses survive, root, tiller, strengthen and become part of the playing surface.
If you are overseeding an already bare area…ask yourself why it is bare in the first place and address the underlying causes first.
The Green Will Still Look Top-Dressed
One concern clubs often have is visual. If we do not order the usual dressing, will the green look unfinished? This is where this autumn method is helpful. After heavy-duty scarification and hollow tining, a surprising amount of existing material can be brought to the surface. Old dressing, thatch fragments, rootzone material and debris all appear. Once the useful material is worked back in, and once Humigranule, BioActive RZ, seed, wetting agent and autumn fertiliser are incorporated, the green will still look like it has been top-dressed and the boost of oxygen will enliven it manifold compared to simply filling the holes with more sand again.
The dressing effect has been created by working with what is already in the green and adding materials that change function rather than simply adding bulk.
Of course this matters politically inside clubs of course, the members see renovation. The greenkeeper sees progress. The rootzone gets something it actually needs. And the club saves the substantial cost of buying, transporting and applying another high-sand dressing. For many clubs, that saving could be in the region of £1,500 to £2,000 before VAT once material, labour and associated work are considered.
That money can be redirected into a proper autumn recovery programme, not spent on the next layer of the problem.
