KNOTWEED OR CRABGRASS FOLLOW UP

Nick Christians
May 29, 2012

On March 23, 2012, I put up a blog post about knotweed.  This annual broadleaf germinates very early each season and is often mistaken for crabgrass.

At that time, I posted a picture of an unknown weed that had just emerged at Veenker Memorial golf course in Ames, Iowa that had some of the characteristics of knotweed, but did not look like the other knowtweed germinating on the course at that time.  This patch did look a lot like crabgrass, but it was clearly too early for crabgrass to emerge.  The first picture below is the way that weed appeared on March 23.

I mentioned that I would return later and see what the weed was.  The second picture was taken in late May in the same location on the course.  It is clearly knotweed.  I'm not sure why the newly emerged seedlings looked so much different than the other knowtweed on the course.  You can see why people mistake some knotweed for crabgrass each year.


Photo 1.  Unknown weed on Veenker golf course as it appeared on March 23, 2012.  It had many of the characteristics of crabgrass, but was clearly a broadleaf.

Photo 2.  Picture taken in late May on the same location where the first photo was taken in March.  It is clearly knotweed.

ISU TURF STUDENTS TREAT LAWNS AT REIMAN GARDENS

Nick Christians

May 15, 2012

The turf club has been treating the lawns at Reiman Gardens on Iowa State Campus  for the past several years.  The first two pictures below are from our spring treatments in April.  I stopped out yesterday to see how the turf is doing on the site. We have had a great spring and everything is looking good.

I also got to see the LEGO display at the gardens.  It will be there all summer.  It is quite interesting and worth the time of a visit.

 

UPDATE ON TEES SEEDED OCT. 25, 2011 AND MARCH 12, 2012 IN CHICAGO

Nick Christians
May 10, 2012

Here is a follow up on a post from March 12 about a late seeding of bentgrass on tees in the Chicago area.  My son Tim is a superintendent there at Makray golf club there.  He seeded the tee in the first picture below on Oct. 25, 2011 and covered it.  He had great results and nearly complete cover on March 12 when he pulled off the covers. 

Pictures 2, 3, and 4  below are of new tees seeded on March 12.  All 4 pictures were taken on May 10.  He is planning on opening them May 11 for play.  In a normal year, I tell people that if they get bentgrass seed in my mid-September, they will probably have to wait until early June to open.  If we keep getting these mild winters and warm springs, I may have to change that recommendation.

Picture 1.  Tee seeded on Oct. 25, 2011.

Pictures 2, 3, and 4 were seeded this spring on March 12.  All tees will go into play on May 11.

Artemisia dracunculoides-THE STUMP THE EXPERT WEED.

Nick Christians

May 5, 2012

Here is the latest 'stump the expert' weed.  It was found on the North side of Ames and submitted to our answer-line person, Richard Jauron.  Richard is pretty good at weed identification, but when he has something he doesn't know, he brings it to me.  I can generally get about 90% of them, but when I get something that I cannot identify, I recommend that Richard take it to our local weed scientist, Bob Hartzler.  Bob almost always figures them out.  

Once or twice a year we get one that is so rare that it stumps us all.  That was the case this week with the weed below.  When that happens, we go to the curator of the herbarium in Bessey Hall, Deb Lewis.  Deb hasn't failed us yet on the really rare plants.

This one appears to be False Tarragon (Artemisia dracunculoides) also known as Dragon Wormwood, Dragon Sagwort. and Green Sagewort.  It is similar to the herb Tarragon, but does not have the taste or aroma that makes it desirable for cooking purposes.  The herb commonly used in French cooking is French Tarragon (Artemisia dracunculus), which has a similar appearance.

While it is found in Iowa, it is very rare.  This is the first one that I remember seeing.  We are on the eastern border of where it is commonly found.

Now, how do you kill it?  I would suspect that 2,4-D, MCPP, and Dicamba would not be good for it, but the picture below is from a lawn that had been sprayed with Trimec earlier and was weed free except for this patch and a Canadian Thistle.  I recommended that home owner ask his lawn care specialist to try a pyridine like triclopyr or fluroxypyr, but I'm not sure that these materials will work.  

If anyone has experience in controlling this one, add a comment below.

HOW OFTEN SHOULD I MOW MY LAWN?

Nick Christians
May 3, 2012

Here is a good post from Rod St.John who graduated with his Ph.D. from Iowa State a few years ago.  He is presently working in extension with Kansas State in Kansas City.

 http://www.ksuturf.org/blog/2012/05/how-to-mow-your-yard-rebuttal-of-a-consumer-reports-article/