Search results

Winter Weather Update and Topdressing Trial

January 10, 2012
Golfers are taking advantage of the uncharacteristically warm weather with a rare January round.

Temperatures dropped into the low 40’s over the weekend as a cold front moved across the state. Considering the weather we have experienced lately however, the “cooler” temperatures haven’t felt so bad. Many parts of the state broke records last week as daytime temperatures surged into the 50’s and 60’s. Temperatures during the month of January have been just over 10 degrees higher than normal. Golfers took advantage of the mild weather last week and dusted off their clubs for a rare January outing.

Overall, temperatures have been above average since last October and this has prevented the ground from completely freezing in many parts of the state. Precipitation totals were above average for the month of December thanks in part to 3 rain events. It appears that nearly all of the precipitation that occurred in December was able to soak into the ground. This was a very welcome development over northwestern Iowa where severe drought conditions are still present.

The threat of turf damage from dessication is certainly elevated with the open winter we have experienced thus far. Dr. Christians provided a nice historical perspective of turf dessication in his posts last week along with the benefits of late fall sand topdressing. We also took the opportunity to put out a couple sand topdressing trials last week to address this issue.

We applied sand topdressing to creeping bentgrass putting green turf exposed to northwest winds that had not received any topdressing for winter protection. Sand was applied at 1/16, 1/8, 1/4, and 1/2 inches. An untreated control was also included in the trial which received no sand topdressing.

Results from this trial should tell us if there are any benefits from mid-winter sand topdressing during “open” winters and how thick of a topdressing layer needs to be applied. Special thanks to Brian Abels, Golf Course Superintendent, Jewell Country Club, and James Legg, Golf Course Superintendent, Briarwood Club of Ankeny for letting us use their facilities for this work.

Pictures of the sand topdressing trial can be seen below. We will be evaluating the effects of this trial in the spring and will post results as they become available.

A wood frame with three layers of chicken wire was positioned over each plot.  The wire helps evenly distribute the topdressing sand across the plot.


Four thicknesses of sand topdressing are being evaluated in this trial for their effect on protection from winter dessication.  An untreated control was also included.





Overall view of winter topdressing trial.  Special thanks to Brian Abels, Golf Course Superintendent, Jewell Country Club, and James Legg, Golf Course Superintendent, Briarwood Club of Ankeny for letting us use their facilities for this work.

Marcus Jones
Assistant Scientist
Iowa State University





Time for Primo/Proxy Applications

March 21, 2012
Forsythia bush in full bloom.  Picture taken March 19, 2012.

The winter season officially ended on Monday. With the mild weather we experienced this offseason, at times it seemed like winter never arrived. Central Iowa saw temperatures climb into the 80’s for five consecutive days last week. According to the National Weather Service, it’s the first time that’s ever happened during the month of March. Four inch soil temperatures are creeping into the low 60’s across most of the state. Forsythia bushes are in full bloom.

So what does this bizarre weather mean to you and your turf? The weather is well ahead of normal and agronomic practices will need to occur sooner than normal as a result. Avoid the temptation to schedule activities solely base on the calendar because this spring has been anything but normal.

Growing degree days (GDD) can help give you an idea of how unusual this spring is shaping up to be. GDD’s are a measure of heat accumulation and are used to predict plant and pest development rates. Daily maximum and minimum temperatures are used along with a base temperature to calculate a GDD value for each day. Below are two maps showing accumulated GDD’s from March 1 through March 20 for 2011 and 2012. As far as GDD’s go, most parts of the state have accumulated 2 to 3 times the number of GDD’s as this same time last year. In fact, it took until April 10 last season to accumulate the number of GDD’s we have experienced so far.

Growing degree day comparison from March 1 to March 20 for 2011 and 2012. 

Michigan State University has conducted research looking at GDD’s for a number of turf applications including Primo/Proxy applications. Their research indicates that the ideal GDD ranges for Primo/Proxy application is 200-500. Our accumulated GDD's indicate that the entire state is within the target range for Primo/Proxy. Now is the time to make your Primo/Proxy application for seedhead suppression of annual bluegrass.

Marcus Jones
Assistant Scientist
Iowa State University



April 17, 2014

It looks like the big winner (or loser depending on your perspective) this winter was perennial ryegrass (Lolium perenne).  We use this species in the Midwest on some golf course fairways and a large number of sports fields. It is also often included in lawn seed mixes.

Perennial ryegrass has good wear tolerance and germinates very quickly in spring and fall.  I find that I will get germination from perennial rye weeks early than I do from Kentucky bluegrass (Poa pratensis) in spring seedings.  It also matures quickly, and recovery from winter damage takes place much faster than from spring seedings of Kentucky bluegrass.  On golf course fairways and tees, we can get the playing surface back in a few weeks from rye seedings, whereas it can take months for Kentucky bluegrass to provide a complete cover from a spring seeding.  We generally seed the rye at 3 to 5 lbs/1000 ft2 in mid-April.  If you had damage on rye this spring, I would recommend seeding as soon as possible.  If you are planning to overseed Kentucky bluegrass, you will likely see little germination before mid-May and then recovery will be painfully slow unless you cover the area with tarps to speed the process.

We had one of the coldest winters in years in 2014, as Ryan and myself have mentioned in blogs over the past 3 weeks.  We have had a few contacts about loss of Poa annua on golf courses, although it does not appear to be very bad in most of Iowa.  Creeping bentgrass (Agrostis stolonifera) damage appears to be minor as of mid-April.   There is also a little damage on Kentucky bluegrass, although that will generally recover from rhizomes in years like this.  Perennial ryegrass is another matter.  We are just beginning to get contacts about rye damage.  The pictures below are form sports fields and golf courses in central Iowa.  This is further south than we normally see winter damage on this species, which makes me wonder how much damage we are seeing in northern Iowa and southern Minnesota.

Perennial rye does not have a rhizome system like Kentucky bluegrass and generally requires overseeding in the spring when damage occurs.  The good news is, you can get it back much more quickly than other species (see the pictures from Vennker Golf Course on Iowa State University campus from 2008).

Let me know if you are seeing winter damage on your area and send me some pictures as well.  It will be interesting to watch recovery as the spring progresses.  

The first 4 pictures are from Jester Park golf course in Central Iowa.  These are mostly ryegrass fairways with a little Kentucky bluegrass mixed in.

The undamaged area in the left of this picture is Kentucky bluegrass.  The damaged area is perennial rye.

 These pictures were taken on a mostly perennial ryegras soccer field on ISU campus.  Notice the mole run in the first picture.  Thanks to Brent Cunningham for the pictures.

This set of pictures is from John Newton, certified golf course superintendent at the university golf course.  It shows winter damage on his ryegrass fairways in 2008.  The area was seeded with 3 lbs rye per 1000 sq ft on April 10.  The second row of pictures show flood damage in May with recovery by the end of the summer.  John had a tough year in 2008.



April 3, 2014

 Winter damage at turf research (prior year)

 Desiccation on bentgrass (prior year)

Winter damage to turf can occur from a variety of causes.  These include diseases such as snow mold, ice cover, traffic, frost heaving, desiccation, and direct low temperature damage.  In recent years, desiccation due to mild conditions, lack of snow cover and drying winds late in the winter have been the biggest reason for winter damage in Iowa (see my blog on this site from January 2, 2012).  Snow mold is sometimes a problem (see blogs from March 11, 2010, Sept. 10, 2010, Nov. 27, 2012 and Dec 8, 2012).  The biggest concern this spring, however,  is likely to be direct low temperature damage.

This past winter has been one of the coldest in recent memory for most of us in the Midwest.  As Ryan mentioned in his last blog, the average temperature over the past 3 months was 14.7 degrees F as compared to a normal average of 22.1 F.  We also hit some very low temperatures during the last 3 months, with low temperatures on some days dropping below -20 F.  Records in Ames show that this winter was the ninth coldest in the last 141 years. The question as to how much winter damage we will see as the turf emerges from dormancy depends on the species grown on the site and on a series of complicated, interacting conditions that occurred during the winter.

Kentucky bluegrass (Poa pratensis) and creepging bentgrass (Agrostis stolonifera) tend to be quite tolerant of cold temperatures.  The fine fescues as well have proven to be quite tolerant in my experience.  Perennial ryegrass (Lolium perenne), tall fescue (Festuca arundinacea), and Annual bluegrass (Poa annua) are more likely to be damaged by low temperature.  The warm-season grasses are generally more susceptible to cold temperature damage.  Bermudagrass (Cynodon spp) is easily damaged, whereas Zoysiagrass (Zoysia japonica) and buffalograss (Buchloe dactyloides) are more tolerant.  It will be on the perennial rye, tall fescue, and annual bluegrass that I expect the most damage as the grass emerges from dormancy in this area.  Creeping bentgrass is very susceptible to winter desiccation, but the continual snow cover that we have had in most regions of the Midwest should prevent this from being a major problem this year.

An even more important determining factor in direct low temperature kill is the condition of the grass going into the winter and the conditions that occur in the localized area during the winter.  Seedling ryegrass and seedling tall fescue that were established late in the fall are particularly susceptible to cold temperature damage.  It is not unusual to loose late seedings of these species in years with less severe winters that occurred this year. Mature stands of these species survive cold temperatures much better if they harden off properly before extremely cold temperatures occur.  Snow cover during the winter tends to be a good thing, and I rarely see damage in cold winters when snow lasts most of the winter as it did this year. 

If there has been intermittent melting, allowing water to settle in low areas, followed by a hard freeze, damage is more likely to occur.  This is particularly true of perennial ryegrass and annual bluegrass damage.  I have observed this type of damage a number of times over the years and I expect to see some of it this spring.

Damage to annual bluegrass is hard to predict.  This species is more sensitive to direct low temperature kill than is either Kentucky bluegrass or creeping bentgrass.  However I have seen years where I expected to see a lot of annual bluegrass damage and didn’t.  There have also been years when I didn’t expect damage and a lot of it occurred.  Again, it is a series of other factors that determine annual bluegrass damage.  These include the condition of the grass going into the dormancy and the combination of weather conditions that develop during the winter.  As cold as it was this winter, I am anticipating quite a bit of damage.  I am getting early indications from the Chicago that quite a bit of damage has occurred on greens and fairways where annual bluegrass is the primary species.  I’ll keep you informed on that as the spring progresses.  Winter damage to annual bluegrass is often quite localized due to variations in winter conditions.  Here in central Iowa, the annual bluegrass seems to be emerging from dormancy in good shape.

In the last two years, I have done a number of blogs on bermudagrass showing up in Iowa turf areas (Aug. 2, 2012, Sept 18, 2013, July 29, 2013, and June 17, 2013).  Another warm-season grass that has become a problem because of the series of mild winters in recent years is Windmill grass  (Chloris verticullata) (Sept. 19, 2013, July 3, 2012, Aug. 6, 2012).  Neither of these species was a problem up to about 5 years ago.  Both species are quite sensitive to cold temperatures.  It will be interesting to see if they survive this severe winter.  Windmill grass is a perennial, but it is also a very good seed producer.  I suspect that this grass is here to stay, even if a lot of the existing plants died during the winter because of the amount of seed in the soil.

Windmill grass in lawn.


Windmill grass seedhead.

Bermudagrass on Iowa State campus in the summer of 2013.

Let me know what you are seeing as the season progresses.  I would appreciate any pictures that might be of interest to others in the industry.



January 5, 2012

It is January 5 and it is 61 F in Ames, Iowa. For those of you not from here, that is very warm. In fact, we are likely to hit an all-time high for the day. This follows one of the driest falls that we have had for a while. We have also experienced some strong northwest winds in the last few days that are ideal for drying out greens.

While superintendents are worried about desiccation, golfers want to take advantage of the warm conditions and play some winter golf. This has been the primary question from golf course superintendents in the last few days. Should I open the course for play, or should we keep it closed?

While I have not done any specific research on the effects of winter play on greens, I have had some experience in this area. In the 1970’s, I was a superintendent in southern Colorado. In the area just east of the mountains, this weather is very common. Drying winds are also a problem. In that area, it is too cold to keep the water on. The soil also freezes, but day-time temperatures are often warm enough to play golf. We never closed. If someone wanted to play golf, we let them on. We had a special cup cutter with a large solid-steel ball on top of it. We would hit the ball with a sledge hammer to drive the cup cutter into the frozen soil on the greens. We had 5 positions on each green where we would rotate the cups during the dormant period of winter. Sometimes play was heavy and I remember a lot of wear around each cup setting by spring. I always worried that this would result in damage after spring greenup, but it never did. I was surprised at how well the greens recovered once the grass started to grow.

You do have to be careful during the few days of spring thaw. If the upper inch is wet and the soil just below is frozen, keep players off. But on frozen soil, you will see the effect of wear on the dormant turf, but it should recover well in the spring. You’re also keeping those few players who want to play happy and if you rely on greens fees, you can make a few dollars for the club.

If you covered greens, leave the covers down. The threat from desiccation this winter is high. Covers are good. If you let the golfers on, let them play to temporary flags ahead of the greens.

I also had a question yesterday from someone who had sand topdressed at the end of the season. The question that brings up is the concern that grinding the sand into the dormant grass with foot traffic may cause additional damage. I have not had experience with that, but I doubt that it will be a major problem unless play is high. If you can, have them play to temporary flags ahead of the greens, but if members insist on playing on the greens, I still think the greens will be fine.

I will want some feedback on this in the spring. The blog provides a permanent record and we can refer back to this in future years when we hit another weather pattern like this. I would also appreciate some feedback from you older superintendents who have lived through this before. Send me an e-mail with your opinion, and I will post it on the blog.

Some trials on winter topdressing are also going out today. Marcus Jones and Nick Dunlap got up early this morning to establish sand topdressing trials on Jewel Golf, north of Ames and in Ankeny south of Ames. We’ll keep you posted on that work during the spring.



January 3, 2012

Nick Christians
January 3, 2012

The article below was published in GCM in July of 1996. It is about the severe desiccation that occurred during the winter and spring of 1996. We have similar weather conditions to those that occurred in 1996.

Articles from Golf Course Management can be found at




January 2, 2012

While this mild winter has been great for holiday travel, it will probably not be good for golf course superintendents. Surprisingly, it is the hard winters that are generally good for the golf course. Snow cover and cold temperatures through mid to late winter protect the turf from desiccation and the golf course emerges in the spring in good condition. It is the open, mild winter with windy conditions like we are getting today that results in drying of the turf (especially bentgrass) and causes damage that can persist well into the spring and even to early summer.

The last few winters have been anything but mild. The white Christmas has been the standard for the last few years and heavy snow cover has been common in many areas of the Midwest. Winter desiccation has been rare and we tend to forget about it. Unless the weather changes soon, this will be one of those springs where severe desiccation is common. In my experience here in Iowa, it is the northwestern part of the state that gets the worst damage because that area lacks tree cover and is exposed to the northwest winds of winter.

So what can you do about it? Greens covers are part of the answer and those of you who covered your greens a few weeks ago should be fine. But, there are many uncovered golf courses in the state. Fairways and tees generally go uncovered and these areas can be badly damaged even on courses that cover greens. Winter watering can be useful if you can do it. When I worked in Colorado years ago, winter winds would kill bentgrass greens and tees if we did not get some water to them during mild winters. It was too cold to charge the irrigation system. The courses had water trucks and it was typical to spray water over the greens every couple of weeks to keep them hydrated.

Topdressing is another way of protecting greens. In the 80’s and 90’s we did some work on this. I will post some information from that work in the next few days. The last couple of weeks I have had some questions on whether it is too late to topdress in January and if it is not, how much topdressing should we apply. I don’t know the answer to those questions. If the mild weather continues, we will try to get a quick trial together at the research station to look at these issues. I’ll keep you informed about the work during the spring.

Winter desiccation on bentgrass.


Watering in the winter in Colorado.


The effect of simple topdressing on bentgrass.

Area that was protected by a cover during a mild winter.


More Winter Damage in Chicago

April 14, 2010

As you can see from Brian Thomson's post yesterday, it was a rough year for greens in Chicago. Here is a post from Ben McGargill, Supt. of Wynstone Golf Club which is just down the street from Biltmore. Ben's greens were covered during the winter. He sent me this picture of the 17th green where the left side had remained uncovered. Ben made no attempt to remove the ice. His greens are mostly Poa. As you can see, the Poa did well under the cover, in spite of the long ice cover this winter and the uncovered area was damaged.

I'll post some of my own thoughts on winter damage tomorrow.

Nick Christians


17th green at Wynstone Golf Club north of Chicago. April 2, 2010.


Winter Damage in Chicago by Brian Thomson

April 13, 2010

Here is a post from Brian Thomson, Superintendent of Biltmore CC, north of Chicago concerning damage from this past winter.

Biltmore CC

Barrington, Ill. (North of Chicago)

Winter of 2009-10

Winter Kill / Ice Damage

Notes by Brian Thomson, Superintendent.

During the winter of 2009-10 we had the longest period of ice cover I have seen in 15 years. In the month of December we received 2.12” of rain, most of which fell Dec 25-26 (1.45”). Soils temps at a 2” depth were frozen starting Dec 19th and did not thaw until March 12th – 85 days later. During that time, ice covered all of our low greens at a depth of 2-4”.

On Feb 18th (~60 days after soils were frozen) we began removing the snow from 9 greens and breaking the ice up on 5 of those greens using a Toro aerifier with solid star tines. The tines did go into the surface of the green and completely broke the ice. The ice was not removed, but left in place to help protect the turf, should the weather turn cold.

A noticeable rotten egg smell came from the greens as they were being aerified. After aerification we did have some sunny, warm days which melted some of the ice. Ice did reform and more snow fell, which lasted until the first week of March.

The greens that had the most ice are push up style greens, in the lowest portion of the course, on peat.

Greens that we removed snow and broke Ice:

Green #1 – Most damage, in low lying areas, all Poa effected (see picture of bent plug). This is a problem green which we have experienced winter kill before in low lying areas, never to this extent. Poor internal drainage and little, to no surface drainage. Green has several “pockets” with no surface drainage. Built on peat (20-30’ thick). Drains were installed to the low areas of the green a few years ago. The grass above these lines survived, however grass just a few feet from the drain lines died.

Green #4- Some damage – surface water flow areas affected. Ice was not as thick as #1, #8, #10, and #13. This green is built on clay (not peat). Have had some areas of damage in the past.

Green #8- very small areas of damage. A newer green (rebuilt ~20 years ago). Does have pretty good internal drainage, however surface drainage is poor. Did have considerable amount of ice. Green is on peat.

Green #10 and #13- Older greens on peat. Both have poor internal drainage and poor surface drainage. Damage was limited to “pockets” on green and areas are recovering quickly. Typically see damage each year on these greens. Did install drainage to the low areas a few years ago.

Removed snow only from the following – all are built on clay, push up greens. Very little ice after snow was removed (less than 1”).

Green #4 and #5- small areas of damage (low areas). Poor internal drainage and fair surface drainage.

Green #9 and #17 – no damage. Good internal drainage and good surface drainage. Greens look very good at this time.



I think good surface and internal drainage is key. I do think some damage is caused by aerification, however in our case I think we could have had more damage if we had not broken the ice and opened the greens up to release the gas accumulation occurring under the ice – no proof of this. All of the damage was in low areas and surface drainage ways, with only Poa affected. Removing snow showed no positive or negative results compared to greens where no snow was removed.

There is a post on youtube of the ice breaking process. It is posted at: