Groundhog Week

It seems like I have started my own Groundhog day, or at least Groundhog Week, where I am in a perpetual loop and the greens look the same week in and out. Switching from recovery to playability mode was very successful and The Rock last weekend went really well. The greens were fully back up to speed as expected and were over 12' on Saturday. The unfortunate part is that they still don't look perfect but the fact they are putting fine makes up for it. They are still putting true and fast today for the Club Championship. 

Due to the early shotgun for the Rock we set lights up around the course so the crew could get started well before dawn ensuring the course be ready. 

Spotlights on 1 & 18 greens

Mowing 16 at 5am

The greens stimping over 12' for the Rock

This past week we did some more work to help the recovery process, but with mixed results. The soil tests that were taken last week came back. I had two sets of tests done; the regular soil test showed that the soils themselves are actually very healthy. The other test is a saturated paste test, which tests the soil with water added to show what happens when the water interacts with the soil chemistry. The test was split into using irrigation water and distilled water on the soil samples. As expected, the irrigation water is adding much more salts and bicarbonates to the system. It also showed that although the numbers are similar on a healthy green (6) to a poor green (10)  the healthy turf is able to withstand the salts, whereas the weak turf and new seed are not able to process it. To use the analogy of a healthy human who can shake off a flu, the healthy greens are comparative; whereas the simple flu can be detrimental to a human who is run down or has a weak immune system.

These three samples were checked using the irrigation water (the areas of interest are highlighted orange)

On 10 we tested a good and bad area to see if there was a difference (there wasn't) but the distilled water freed up potassium and resulted in a lot less salts and bicarbonates (in orange as above) 

Anticipating the outcome of the test results, the greens were flushed on Tuesday. Gypsum was applied first to help flush the salts as the water passed through the system. As the morning progressed, the healthy greens flushed as normal, with the surface water disappearing when the greens 'burped'. However, we started to notice that the thin greens did not drain. Pulling a core revealed that that they were holding water at approximately 4" due to the gypsum no longer being effective enough to move the salts further; the salts created a perched water table. The picture below is not the clearest, but the saturated area can be seen near the top while the lower end of the core is as expected. 

1 green puddling up and not flushing

We sprayed an organic acid to help move the salts further but it only moved them another 2 or so inches. The plan is to reapply gypsum and the organic acid on Tuesday and hopefully it can flush the salts completely out of the system. It is difficult to get the required results as the irrigation water is less than perfect and adding to the problem, so we have to rely on the work-arounds to help. Ideally a large rain event would provide clean water to completely flush the system and help the greens return to normal. 

Flushing the greens

The sensors in the greens confirmed what we were seeing on the surface and in the cores. The sensors are set at 2 & 8 inches. The graphs below are for the upper and lower sensors. The rain event on the 21st can be seen. While a nice rain, and one that would normally be appreciated, this one was not heavy enough to flush the greens. However, it can be noted on the upper sensor that the rain helped push salts past (as it registered a spike in salinity,) but only the sensor on 18 showed a spike in salinity on the lower sensor as the salts passed it. 

The flush on 9-24 can be easily seen also. At the upper sensor the salt levels spike as it passes the sensor, while the lower sensor stays resolutely flat for 1, showing the salts never made it to that level.

The upper (2") sensor graph for 1 & 18

The upper (2") sensor graph for 1 & 18

We finally have confirmed our suspicions and have a definitive answer to why greens that should have quickly recovered from some mechanical damage and scorch have not been recovering. It has been an extremely frustrating period for me, as well as for all of the members. We are trying to fix a problem with a component that adds to the problem. We will continue to do as much as we can to flush the salts in order to push growth and get the seedlings to pop; but until we can get near a neutral base line, it will be difficult. A large rain event followed by some warm and moist  days would be the ideal first step to the road to recovery, as it will flush the system and ensure we don't have to rely on the irrigation water to grow the seed. As I have mentioned a number of times before, a Superintendent is never happy with the weather, even when it has been as perfect as what we have had. The greens will be flushed again this upcoming week and we will continue to push as much growth as possible, while keeping them playing well. 

Other than the few greens that don't look great, the remainder of the course is in great condition. While the beautiful dry weather has been causing problems with getting the greens to recover, the flip-side is that the course is playing hard and fast, which is never a bad thing.

Finally this past week was the first Ladies Behind The Scene Tour, which encompassed 9, 10, 12, & 13 culminating with a nice lunch at the Kohl Lodge. I'm looking forward to next Monday's tour which will include 3,17 & 18.

As always if you have any questions please let me know alan@ledgerockgolf.com

The Rock 2013

The last few weeks have been a challenge. While the course overall is looking good, there are still issues with some greens. What happened to them and the corrective action taking place has been discussed in previous posts. So, what will the greens be like for The Rock tomorrow?  

From tee to green the course is in top shape and nothing out of the normal should be expected. Although the greens will be playing close to normal, some of them are still not looking their best. We have had some good recovery but the majority of the seed did not come up as expected and the thin areas have not grown out as expected. This is exceptionally frustrating as we have done everything to encourage them to heal. I have had numerous consultants out over the last two weeks and they too are baffled at why the thin areas are not growing out. All of them, including myself, expected the greens to fully recover in a couple of weeks. In most areas the plants are not dead; they have healthy shoots and roots but the top growth is not happening. 

I had some soil testing done and a water test taken at the onset of the conditions to investigate causes of the damage. The bicarbonates in the irrigation water have increased 25% since June and the salt concentration has nearly tripled. While we knew earlier in the year we were starting to have problems with the irrigation water, we had been working around it. In simple terms, the irrigation water is tying up nutrients in the soils making them unavailable to the plant and it increases salt, which was discussed in the spring. This added salt has us cautious right now so as not to create additional issues. A gypsum application before the rain last week did not yield the results we expected; it should have helped free up the nutrients. That rain event only provided ~0.3" of precipitation. Although it washed the gypsum in, it was not enough to flush it through to work fully. We have not had much rain since aeration (<2") and have had less than 1" since the issues appeared. These rainfall amounts are not enough to flush the greens (as they were spread out) so I believe the plants are struggling from lack of quality water and that we will see quantifiable recovery after a good period of rainfall.

2 Green on Labor Day

2 Green yesterday - while far from aesthetically perfect, the recovery is noticeable.

I initially had been treating the greens as a grow-in to push growth; since it was not recovering as expected a decision had to be made for The Rock. The extra water required to get the seed to pop and the extra fertilizer to push the growth are not desirable for green-speed. We were faced with a tough decision:  continue the recovery process or prep the greens for The Rock.  The decision was made to prep the greens since the turf is healthy overall, the brown areas are still alive (although not pushing growth), and the weather is perfect. This means that recovery may take a little longer overall (and gives us time for a prolonged precipitation event), the greens will all be up to speed and consistent for the upcoming tournaments. They will still have some thin and brown/tan areas but these are putting fine; the turf is short so the surfaces are even, just a different color. 

In preparation, the greens were topdressed lightly last week to help smooth them further and it helped greatly. They are all back to regular mowing heights and the green-speed today was back just over 11'. It will increase to normal over the next few days.

A question surfaced regarding the plugged areas on greens.  I discussed this briefly in a previous post.  It is not necessary for the plugs to be consistent in size and shape or to completely fill in the area.  The spaces between the plugs protect healthy plants/ new seedlings by keeping the mowers above them.  The bentgrass can also creep into the voids.  For this reason, plugging is quicker than sodding for smaller areas.

Over the last few days the worst looking collars were sodded to help the aesthetics. The sod is from our nursery and is the same variety as the bentgrass on the greens, however, it is maintained at greens height. This means that it might look a little odd on the collars for a few days until it grows up to the collar height. Once it knits, it will be aerated, rolled and topdressed to make sure it is perfectly smooth.

Sodding 4 collar

17 before the collar was sodded

17 after the collar was sodded

So to sum up, the greens are consistent and running at their normal speed but they are not all aesthetically perfect. The recovery, while it has not gone as quickly as predicted, has still shown a lot of improvement and over the next few weeks the greens will recover as they need time to grow out. 

As always, please e-mail me (alan@ledgerockgolf.com) with any questions you may have.  

So why do we aerate and why now?

As promised in the last post, I will discuss the necessity and timing of aeration.  Let's first begin with a course update. 

Overall the course is back in top condition. Over the last week the crew worked tirelessly to get caught up on the backlog from aeration and the wet week that followed. 

The greens that had issues are recovering, albeit slowly. I am very impatient; I have to keep telling myself it has been less than a week since we discovered what was going on. I expect to see the rate of recovery to pick up over the next few days. I held off fertilizing them right away and made sure the plants were strong enough to take on the pressure of being fertilized and the associated extra growth; otherwise they could overfeed on nitrogen and die off. 

They were fed with biostimulants, calcium and other micro-nutrients first to prepare them for the larger fertilizer applications on Thursday and Friday. It takes a day or two for the plant to take the fertilizer up and for it to have an effect. The pick up in growth this morning shows that they are reacting to it and starting to actively grow. The new growth is pushing through moving the brown tips upward. The amount of green tissue starting to push through can be seen in the picture below and if you move the sand around, more plants can be seen ready to break through. 

Each days mowing will take off the brown tips, so it eventually fades out as the green leaves grow. The two pictures below are from 1 green; the top one is Monday around 11am and the lower one from the same angle at 11am today. The recovery, while it still has quite a bit to go, is notable even after 4 days. 

The greens were also seeded this week. We used Job Saver tines on our aerators (pictures below). These little tines are designed for overseeding into an existing canopy. They make shallow holes for the seed. The greens were then rolled essentially planting the seed to protect it and keep it warm and moist so it germinates. Bentgrass seed germinates relatively quickly so I expect to see some more green fuzz popping up by the middle of next week to help speed up the recovery. 

We will continue to fertilize and push the growth, along with lowering the height of cut. We have been lowering the height daily for the last few days with no negative effects. Once the lowered height reaches the sand we will slow the rate at which we lower the mowers. The greens need another very light topdressing to get them perfectly smooth. While they are fine right now, once the mowers get back to cutting at 0.1", it is essential they are perfectly smooth or the greens will be damaged from scalping. The picture below shows one of these imperfections; it is the darker green spot in the lower middle. If it is left un-topdressed the mowers will scalp it leaving a bare spot. 

When we topdress, depends on the health of the plant as we do not want to do any more damage. The topdressing from aeration has been worked in on most of the greens so adding a little more will not cause an issue.  It is essential however that the plants are healthy enough to withstand the stress from the broom. With it being a light topdressing it is easily worked in so, again, it is not as much of an issue as it was during aeration when the holes had to be filled. We plan to work it into the schedule as soon as the turf is healthy enough for us to do so.

So, the answers to the title questions:

The main benefit of an aeration is to provide air and water channels for the roots. The roots are a vital component for the plant as they are the location where the plant takes up nutrients and water. The longer and healthier the roots are, the healthier the plant and the greater it's ability to withstand stress. There are numerous ways to aerate; from solid tining (sticking a fork in it!); to hollow tining (removing soil); water injection (creates tiny channels); deep and shallow tines (varies on how deep you need to go); drilling; slicing and some more I'm forgetting. There are various methods to accomplish these procedures also, each having varying degrees of surface disruption and area disturbed beneath the surface. For example, a spiker (below) leaves a small triangular hole that provides a lot of area for air exchange but it is not a deep machine; it can tuft the surface so it would not be as acceptable as a small needletine, which has less surface area but penetrates deeper and leaves the surface intact.

Most of the deeptine machines also kick as they move through the soil. This action helps fracture the soil and loosen it, reducing compaction and creating more air/water pockets for the roots. The Wiedenmann (below) we used on greens was adjusted to minimize the kick as it was in sand;  the main goal with it was to leave deeper channels through the mat layer.

These methods of aeration also help with soil issues. If a soil does not drain well (like a native soil green), the holes can be filled with a better draining material, improving the composition of the entire profile. 

The hollow tines remove material from the soil. If the goal is to modify the soil, removing a core is better than pushing a hole into the soil, which can cause compaction at a deeper level. Hollow tines also help remove thatch, which is the organic material plants create. Creeping bentgrass is a big thatch producer as it has stolons (runners) that are above the soil. As the plants grow this runner level gets thicker and becomes spongy. On a green it creates a lot of issues from both a golfer and maintenance prospective; the greens are soft, hold water, difficult to cut (as the mower can dig in and scalp),  can dry out quicker as thatch can become hydrophobic, and numerous other issues. Removing it is essential to have quality greens, especially if they are bentgrass. Physically removing the thatch greatly helps in keeping it in check. In most cases it is recommended to remove 20-25% per year, just to keep up with the production. That is over 11 triaxle loads of material per year on the greens at LedgeRock alone! Skipping an aeration can be very difficult to recover from when you consider the volumes that are involved.

Topdressing helps reduce thatch also by simply burying it, which dilutes the amount of the organic material in a given volume. As I mentioned in an earlier post, topdressing also keeps the putting surface true and smooth which helps increase green-speed. Topdressing also can be beneficial when drainage is an issue. As the sand layer builds up it creates a free draining layer for water to move through to drainage channels, which are essential so the water has somewhere to go.

Diluted thatch (mat) and topdressing layer on a green

And finally; why do we do it when we do?

There are a number of factors that influence the timing of aeration. Non-evasive aeration, like needletining, can be carried out pretty much anytime as it does not affect the playabilty of the course; however hollow tine aeration needs to be carefully planned. 

Recovery time drives the timing. The turf should be aerated at a time that minimizes the down time for the course. On average a course can be fully back in play within three weeks from the start of aeration. This period depends on how aggressive the aeration was and how long it took to complete. Sometimes the process itself can take 4-5 days but full recovery should be within 2 weeks from completion provided the weather is conducive to growth. 

Here at LedgeRock we used to aerate as soon as we could in the spring; We usually had all the greens completed by the end of March, which was ideal as it was out of the way and all resources could be directed to prepping the course for the season. The downside was that it took until late April to early May to heal. This is due to the fact the soil temperatures are not consistently warm enough for turf growth until that time. As discussed back in the spring, the slow warm up delayed recovery even further. The decision was made about 4-5 years ago to move our spring aeration to mid- April, when the soils usually start to warm up, so that the course would be playable longer if March and early April were nice. By doing this, recovery time is usually in the 3 week range as opposed to 6-8 as it was when we first started. 

For a similar reason, it was moved to an earlier date in the fall. It was scheduled right after Labor day, however, the temperatures started dropping and recovery slowed. In 2007 there were traces of aeration holes all winter, right up until the spring aeration; almost 7 months! Admittedly they are not all great months for golfing but had they been aerated earlier, they would have been fully healed by mid - September, leaving 6 months of quality surfaces.

The USGA also brought to my attention that moving these dates would greatly reduce Poa annua encroachment. Poa annua is a winter annual which likes cooler weather to bentgrass. By aerating earlier, the bentgrass is more competitive and can close up all the holes, not leaving any bare areas where Poa can get established. This is why you may see courses that are predominantly Poa, aerating when the temperatures are cooler. Since Poa is not as strong of a plant as bentgrass, the cooler temperatures also help it recover from the stress that the aeration procedures put the turf under; Poa would be more likely to die during the summer heat.

Of course you can run into issues if the weather changes a little, as happened to us this year; but the average pattern has to be used, otherwise there never would be a right time. 

This USGA article is a nice resource on the timing of aeration.

Have a great week and enjoy the beautiful weather!

Labor Day has come and gone and with it brought in the beginning of meteorological autumn. The end of summer brings cooler nights and perfect golfing weather, which incidentally is perfect turf growing weather. 

WARNING! The following post is rather long as I discuss the last two weeks.  To those of you that may not need to something to sleep to, I will sum it up in one paragraph:

Overall the course has recovered well from aeration and we are getting back on our regular maintenance schedule. Some of the greens had some issues with turf thinning, primarily in the areas with excess topdressing; which heated up burning the new leaves as they grew through the sand. The majority of the crowns were not damaged and are pushing through new growth so recovery should be pretty quick. I am confident that bar a few scars here and there they will be in great shape for the Rock - provided of course the weather cooperates.

For those of you that need some good material to put you to sleep and/or want to find out in detail what happened, read on!

5 green this morning; the burned turf is already recovering

I had been delaying the latest update until the course was fully healed from aeration to let everyone know how well it healed. The tees and fairways have healed up nicely. The verticutting on the fairways, and subsequent grooming, has them looking and playing beautifully. The topdressing on the tees has helped reduce the thatch on them but they will need more coring and topdressing to remove more. This will ensure the thatch does not build up to the point where it becomes an issue. Luckily this can be done during play without too much disruption and can be done anytime. We will schedule it at the end of season. 

 Looking back on 13 on 8-30; the greens were healing nicely and the tees and fairways were nearly 100%

The last thing left to do is to topdress approaches to keep them firm. A few are still a little wet and weak from the work so we are holding off until they are healthy enough to withstand the brooming. It will not affect play much and will be done in a few hours.

So to the big question: how are the greens? The simple answer is fine, but we have had some issues. As covered in the last few posts we had some issues completing aeration. On the Wednesday we were supposed to open back up, there was still some topdressing to be completed, which should have been easily completed in front of play. As with the earlier part of the week, we ran into problems with equipment which delayed us getting them done. The vertidrain started ripping up turf in areas, which needed to be repaired and the machine adjusted to stop it. This delayed the topdressing. As the morning progressed the temperatures rose and I had to stop topdressing to prevent damage to the turf. The damage occurs because the drag brush causes abrasion to the plants as it moves the sand; these abrasions weaken the plant and the heat exasperates it. So while the delay was not ideal, the turf appreciated it and there was no damage, but if you were one of the few that tried to play that day, please accept my apologies.

Some plugs on 1 green to repair the damage from the deep tine machine

A picture of the deep tine hole; showing the difference between it and the depth of the regular aeration channels which can be seen in the top few inches

A cross section of a regular aeration hole

After that hiccup the remainder of the topdressing went extremely well and the greens started to heal nicely. I waited until the following Tuesday afternoon to mow. With the course closed, it meant that there was plenty of time to make sure the first cut went well; the dry turf provided good conditions to mow and not pick up sand. I discussed in this earlier post the benefits of mowing when the turf is dry.

The greens looked good after the first few cuts, but the cut was a little scraggly. I then switched to the grooved rollers to get a better cut. However due to the length of the grass and the height the mower was set to, the grass was still not being cut as well as it should. It is difficult to explain the detailed reasons but a reel mower can only cut a certain amount of grass at a time based on it's speed, height of cut and number of blades. The height of cut was throwing that ratio out so I raised the mower a little closer to the height of the grass. It worked out perfectly, and the cut was beautiful. Everything looked on track for a speedy recovery. 

The cut on the right is after raising the height of cut by 0.025" - the mower was able to cut more efficently

The next day I noticed some browning on the greens. My initial reaction was the mower had scalped but it hadn't. In most of the spots, the sand was still visible and the color of the sand was causing the browning. Looking closer, the tips of the leaves were browning a little. It was nothing I hadn't seen before and I put it down to tip burn, probably from the fungicide/insecticide/fertilizer application earlier in the day. There were a number of new plants growing through the sand so the damage was just on the leaves. I was not concerned as the crowns were still pushing new growth, meaning the plants were still alive. Once they pushed through the sand, everything would look fine.

On Saturday everything was still fine; the plants were pushing through and the tips were a little browned. Turfgrass is like a finger nail. Basically the crown is like the cuticle and the point that the growth originates with the tip is the oldest part. This is the main difference between a grass plant and a tree as the new growth on a tree is at the tip.

8 tee shortly after it was aerated

When I came in on Labor Day, I was expecting to see these areas greened up, unfortunately the opposite was the case. The areas had completely browned out and the tips had burned back to the soil. There was no discernible pattern that would give an indication of a cause, nothing we had sprayed should have caused it; the weather - while not perfect - was not horrific. For one of the first times in my career I was stumped. The worst thing one can do at this point is do something in a panic as it could make things worst. It took me a while to clear my head of the shock and to start to dissect the problem to find the cause and the solution.

The biggest problem was that I was comfortable with my decision that it was fine on Friday and Saturday and now the turf was fading away while nothing had changed. Was the damage done or was there more to come? John, my assistant felt it was mechanical damage and I agreed that there was some as you could see lesions in the plant where it had been torn by the topdressing. I was not 100% convinced that that was the only factor. If it was all mechanical damage it would have been more widespread and be seen on more greens. 

Pouring over all our records for the prior two weeks didn't reveal a clearer picture. I went back out to pull some more plugs and see what was going on at the sites. The plugs revealed, that just like earlier in the weekend, the crowns were still green and alive and pushing new growth. But why were the leaves dying? The damage looked like scorched turf but we had been drying the turf out since the previous weeks rain, so it wasn't from too much moisture. The soils still had plenty of moisture and wilt and wet- wilt were both ruled out. 

Then I remembered back to a topdressing a few years ago where the kiln dried topdressing had not cooled down upon application and it burned the turf. The sand had been cooled when we applied it this time but could something else have caused it to heat up. As I started to work through the situation, I found the answer. 

Thinking back over the weather the previous few days, it had progressively been getting hotter with the humidity increasing. The turf on the greens had started to rot as it was too wet after the precipitation and due to the fact they were holding moisture, we had stopped watering them. While we were monitoring for wilt, we did not realize the areas where the topdressing was heavier and therefore exposed were heating up and did not have timely irrigation to cool them off. As a result, when the new leaves pushed though to the surface they were getting baked by the heated sand, killing them back. This is not something that one expects; while we were concentrating on reducing moisture levels to ensure the plants survived, they were actually cooking in the sand. Once I had my revelation, a clearer picture appeared. I now realized that the damage was on greens,or areas of greens, that for one reason or another had more sand on them and therefore slower to grow through. I also found the answer as to why the aeration holes were green in the browned out areas. In these areas, the turf was gone; the new turf had grown into them. The new growth was not buried and therefore not heating up.

Turf canopy temperature on an exposed topdressed area (after syringing)

Turf canopy temperature on a turf area (after syringing) beside the picture above

Once I realized what was happening, I immediately watered the greens and set up a program to water them overnight. The difference on Tuesday morning was startling. They looked quantifiably better.

On Tuesday I had a soil consultant out to rule out an issue in the soil, which we were able to do. He came up with the same answer that I did; i.e. the turf was being burned by the exposed topdressing. We also had a USGA Green Section agronomist out to offer his opinion and validate our course of action.

The upper picture is the top of the turf, when the sand is blown back (even just a little like here), the healthier crowns can be seen

The good news is now that we know fully what the issue is we can manage the recovery effectively. The better news is that there is a lot of healthy crowns beneath the sand that are pushing new growth. The healthy turf in the aeration holes is an advantage also. This means that they will look a lot better as soon as the new leaves pop through to the surface. There will be a few small areas that may need plugs or sod but overall they will recover pretty quickly. 

So what does this mean for aerations going forward? The deep tine aeration is essential to the future health of the greens. It might look like the extra topdressing that was needed to fill the deep tine holes added to the problems, but the timing of the topdressings is essential in the future. The equipment failures that caused the delays this year had a domino effect on the timing of when the greens were topdressed. The length it took to topdress was a lot longer than normal and the turf was growing all the way through. The turf was at different lengths when we topdressed affecting how the sand was worked in. Going forward, provided everything goes to plan, it will reduce these risks and we now learned to make sure we watch the heat of the sand on top of everything else.

Cross section showing the topdressing on the green and an aeration channel

Not to leave the remaining greens out, they have recovered beautifully, showing that we were on track to have everything recovered by the (now rescheduled) Club Championship. They would have been a little slow but fully healed over, which makes the thin greens even more frustrating.


 A member asked me why the fans were off and if had an effect on the greens that thinned out. The answer is a little contradictory but hopefully it makes sense. Due to the fact the greens had holes in them and were covered in sand our maintenance program had turned to a recovery program. As such the holes were providing big air channels for the roots so it was not as much of a concern. As the humidity rose and we looked to dry them out, normally we would start them up; however, the roots were severely compromised by aeration (this is temporary, caused by the stress, heat, additional fertilizer and in particular the excess water needed for a quick recovery. Once regular maintenance starts back, the aeration channels help increase root mass.) Due to the compromised roots we didn't want them drying out too quickly (as would occur with the fans) so it was easier manage them with the fans off. As you can see this job is a fine balance between contradicting items!

The last item that came up is one that always comes up at aeration time. I have discussed it in previous posts but will dedicate the next post exclusively to it. 

If you have any questions on the greens or the course, please do not hesitate to contact me as I am always glad to answer your questions. I can be reached via e-mail at alan@ledgerockgolf.com