FOLLOW UP ON MOSS CONTROL

Nick Christians
April 27, 2012

Here is a follow up post from Mark Newton, Supt. of Ames golf and CC.  The last one was on August 3, 2011.  See that blog for more details.

Here is Mark's cultural and chemical protocol from last year.

In the fall of 2010, 1 week after our core aerification (1/2” tines on 2” spacing, 4 inch deep) we started the heavy moss treatments with Quicksilver. These started on September 14^th, and were sprayed every 14 days at the 6.7 oz / acre rate for three consecutive treatments, also included was a spreader sticker and tank buffer to get the PH to 6.5. Also we bumped the fertility way up on the greens, putting 3 sequential applications of 7-7-7 fertilizer at .4 lbs of N per 1000 every 2 weeks, also increased our mowing height to .140 with two rolls per week to help keep green speed. This gave us the most control and reduction in the moss, reducing the population by 40-50% and in some spots completely eliminating them.

In 2011, we are continuing the applications but on a more regular basis with lower rates. The label gives us .4lbs of AI per acre per season. That is 26.8 oz of product per acre in total. To date and future applications are shown below:

- April 6^th 2 oz/acre Complete

- May 10^th 2 oz/acre Complete

- May 24^th 2 oz/acre Complete

- June 17^th 4 oz/acre Complete

- June 27^th 2 oz/acre Complete

- July 11^th 1 oz/acre Complete

- July 25^th 1 oz/acre Complete

- August 7^th 2 oz/acre

- August 21^st 4 oz/acre

- September 6^th Greens Aerification

- September 13^th 6.7 oz / acre + Spreader Sticker

*Note – Greens height in spring start up was .140, lowered to .120 by May 15^th and remained at that height until 2 weeks ago with all this heat back to .130 so I don’t have moss free but dead greens. On a normal year would still be at .120 with 1 heavy roll every Thursday, light topdressing every 3 weeks and 1 verticut / month when weather permits

In this program we also have bumped up our fertility of the greens from prior years, and included more applications of Daconil Ultrex to further aid in the moss treatments. These treatments other than the last one on September 13^th will be put in with our regular spray program of Garys Green Ultra at 9oz/M, Tuff Turf at 4.5 oz/M, PK Plus at 4.5 oz/M, primo at .125 oz/M, and then a rotation of Fungicides. These include, Daconil Ultrex on every treatment (ranging from 5lbs/a to 10), Headway, Banner, Heritage TL, Instrata, and Emerald. Pending on weather a Banol or FORE application might be made.

Additionally for cultural practices we tend to keep greens a little dryer than in previous years with more hand-watering and deep watering. We also make sure that when we do a verticut we are always spraying the next day to not only aid in the recovery and have the best chemical controls, but to decrease the chance of spore transport and giving open areas where it can establish. 

 Here is a picture from June 10, 2010 showing how much moss was on the 18th green

 Here is a picture from yesterday April 26, 2012 on the same area.

One warning from me, it is not unusual for moss control programs to appear to be successful at some times of year, but moss tends to come back.  We'll keep monitoring this site over the next couple of years.  Hopefully Mark has come up with something that really works.

CRABGRASS APRIL 12

Nick Christians
April 12, 2012

We have had three mornings with frost on April 10, 11, and 12. I took a walk on campus on the afternoon of the 12th to see what the impact of the frost had been on the crabgrass that I observed on April 2 (see earlier post). Crabgrass is very susceptible to cold damage, particularly in the seedling stage. I expected the crabgrass to be dead, but to my surprise, it appears to be doing fine. The crabgrass is in a somewhat protected area around the horticulture building, but it is an area that did have some frost.

I am still not seeing much germination of crabgrass in more exposed areas on campus and we have not seen any emergence at the horticulture research station as of April 12. It did get down to 20 F at the research station on the morning of the 11th. If any crabgrass was beginning to peak through, I would expect it to be dead. I'll continue to monitor the early germinating crabgrass over the next few weeks and let you know what is happening.

The trial in which we are applying Baricade and Dimension on April 1, 15 and May 1 to separate plots is continuing. As soon as I have some results from that work, I will put up a post.


Figures 1 and 2. Crabgrass by the horticulture building on the afternoon of April 12 after three mornings with frost.

WHEN SHOULD I SPRING SEED?

Nick Christians
April 10, 2012

With the warm weather that we have had, people have been asking about whether they should seed now or wait a few weeks.

Spring seeding is hard, no matter when you do it. Spring seedings often turn to crabgrass and other annuals and may take a year to mature into a real lawn. You can use a selective preemergence herbicide called Siduron which will selectively kill the annuals and let the perennials like Kentucky bluegrass and perennial ryegrass emerge, but that is expensive and difficult.

The best time to seed remains late summer to early fall. I would set August 15 as the best time to plan your seeding in central Iowa.

If you must spring seed, give it a little time yet. I am currently telling those who contact me to wait until after May 1. As we saw this morning, we are not past the frost-free days yet. Seedlings, particularly perennial ryegrass, can be susceptible to cold temperatures in the spring.

If you have to spring seed, I would recommend the application of Siduron with the starter fertilizer to control the annuals. If you end up with a lawn of crabgrass, don't give up. The perennial grasses will be in there. The annual will die in the fall and next spring you can put on a standard preemergence herbicide to control them.

Other standard preemergence herbicides will not work at the time of seeding. They will kill the crabgrass, but they will also kill the grasses that you are trying to seed.

The new herbicide Tenacity (mesotrione) can be used for spring seeding of Kentucky bluegrass, but leave that to the experts. Your local lawn care professional can tell you more about the product.

March Weather Summary and Frost Watch

Although we have been spoiled by unseasonably warm temperatures frost could be an issue for a little while longer.

Keep the winter jacket handy at least for a little while longer. After experiencing summer-like weather conditions during the month of March, most of the state is under a freeze watch for Monday and Tuesday night. These more “normal” temperatures will feel anything but considering the very abnormal spring temperatures to date.

Temperatures in central Iowa averaged 55.7 F during March which is 16.4 degrees above normal. Overall, there were 12 days during March when the daytime temperature was in the 70’s or 80’s. The warmest day of the month occurred on the 16th with a high of 84 F. Now, we must prepare for frost. Historical weather records show that the average last date for frost occurs sometime between mid-April to the first week of May depending on your location in the state.

So what exactly is frost? Frost is the formation of white ice crystals on an exposed outside surface such as leaf blades. Annual plants are often more sensitive to frost and will need to be brought in or covered to be protected from the freezing temperatures. Luckily, our perennial turfgrasses are more tolerant and frost in and of itself will not cause damage to plant tissue. However, damage from frost can occur if there is traffic on the turf while frost is present.

Cart or even foot traffic is enough to cause damage. Because the cells within the plant are primarily water when the temperatures gets below freezing this water can also freeze. Traffic on frozen turf causes the ice crystals to puncture cell walls within the plan. Even though the turf will appear alright the damage has occurred internally. Frost damage symptoms include white to light tan leaves where traffic has passed. In time, the turf will acquire a brown to blackened color. Damage is usually limited to leaf tissue and will remain until new growth replaces the damaged turf. Mowing will help remove some of the damaged tissue and improve the overall appearance of the turf. In severe cases, damage can affect the crown of plant.

Frost damage on a creeping bentgrass fairway.  Here, damage was the result of cart traffic on turf when frost was present.

It’s difficult to prevent frost from occurring and perhaps the best strategy is communicating with the golf course staff. Have them to pay special attention to low-lying areas and shady areas. Cold air tends to settle into these areas and will likely be the last place frost melts. Just because there isn’t frost on the putting green which is exposed to full sun in the morning doesn’t mean the entire facility is clear.

Irrigation can be used to help speed up the melting process through the release of latent heat. When water changes from a liquid to a solid by freezing it gives up heat. In actual practice, surface temperatures will be held around freezing as long as liquid water is available. A light syringing of the turf can aid in this process.

Covers can also be used to protect turf from freezing temperatures although placing and removing covers is a labor intensive process. Newly seeded turf or renovated areas where recovery needs to occur will benefit from the heat trapped under the cover.

Until you reach your frost free date, keeping people off the course when frost is present is the best way to prevent damage.

Marcus Jones
Assistant Scientist

Creeping Charlie or Henbit?

Nick Christians
April 6, 2012


Here is a common question from this spring. It comes from the ISU answer line specialist, Richard Jauron and it originated from a county extension office in central Iowa.

The question is, "is this creeping Charlie/Ground Ivy (Glechoma hederacea)"? The answer is no, even though the leaves look like creeping Charlie. The pictures are of henbit (Lamium amplexicaule). Both are in the mint family (Lamiaceae) and both have square stems, but the henbit grows upright and does not spread like creeping Charlie.

The reason that we see so much henbit in the spring is that it is a winter annual. It germinates in the fall, often after herbicides have been applied. It then appears early in the spring. It is one of the reasons that I prefer late fall treatments with broadleaf herbicides, in October and even November over earlier treatments.

You can treat for it in the spring, but remember that your other landscape species are very susceptible to broadleaf weed controls at this time of year.

Pictures courtesy of Richard Jauron.

HOW LATE IN THE FALL CAN I SEED? - UPDATE

Nick Christians
April 5, 2012

On March 12, I posted some information on a late-fall (Oct. 25, 2011) seeding of bentgrass at Makray Memorial Golf Club near Chicago by Supt. Timothy Christians. Some of the newly seeded tees were covered during the winter and some were not. The subject of the post was the surprising success from such a late seeding.

The spring has continued to be unusually warm in the Chicago area. The following two pictures are from April 3. The first one is of the tee that had been covered and the second one is of the uncovered tee. They have both been mowed by April 3 and both will be open much earlier than usually would be expected.


Tee that had been covered during the winter.




The tee that was seeded on Oct. 25 and was not covered during the winter.

Early Zoysia Green-Up in the Transition Zone

Nick Christians
April 3, 2012

Here is a post from some friends in St. Louis. Ryan was an Iowa Stater who graduated 3 years ago. They are also having a very early spring.

By: Ryan Madden and Nick Zerr

Nick Zerr is the Class A Superintendent at Sunset Country Club in St. Louis, Missouri.

Ryan Madden is an Assistant Golf Course Superintendent at Sunset Country Club in St. Louis, Missouri.

With the unseasonably warm temperatures during the entire month of March, Zoysiagrass has not only begun to green up and emerge from dormancy, but it is growing in full force. At Sunset Country Club in St. Louis, Missouri we have Meyer Zoysia tees and fairways. As of March 21, 2012 we have had 755 growing degree days compared to 560 on the same date in 2011 using 32 degrees as a base. Usually we see green up sometime in mid to late April and do not begin to mow our Zoysia until late April to early May. However, this spring has already thrown us for a loop. We began to see our Zoysia emerging from dormancy the first full week of March. It was completely greened up and out of dormancy by March 21^st and we began to mow it the last week of March. We have noticed that our fairways are a week or more ahead of our tees. We can contribute this difference to mowing height. The higher the mowing height in late summer and early fall, the faster the Zoysia emerges from dormancy the following spring. Obviously, the turf is healthier at a slightly higher mowing height and endures winter stress and dormant herbicide applications much better. Our biggest concern with early Zoysia green up is the threat of a freeze or a heavy frost. In St. Louis, we are not frost free until May 5^th and in 2011 we had a frost as late as May 11^th. Our preventable measures for frost include raising our mowing heights this time of year and running our irrigation system to burn off any frost after it occurs.

You can see our tees in the foreground are still mostly dormant while our fairway in the distance has emerged from dormancy. Picture taken March 21, 2012

Same picture as above but taken March 23, 2012.

This is a different location on the course as the previous pictures but a closer view. Picture taken March 21, 2012.

This picture is of the same fairway as above, but a very close view. Picture taken March 21, 2012.

Same picture as the ones above. However, this one is taken after our first mowing on March 26, 2012.