Wednesday, July 25, 2012


Nick Christians
July 25, 2012

Next week, I'll put up a blog about watering lawns, but this week I want to concentrate on trees.  I am not watering my own lawn and it is crunchy dry.  I did spend the weekend, however, watering my young trees and landscape plants.  I have a lot of money invested in landscaping and I don't want to lose it.

Here are some thoughts by Dr. Jeff Iles, chair of the Department of Horticulture here at Iowa State.  This is his specialty.  At the end of Jeff's thoughts, I will include a link to a webinar on watering.  It is 90 minutes long and covers everything from tree fruits to landscape plants.

From Dr. Jeff Iles:

Watering Landscape Plants

It’s dry.  Very dry.  And it just might stay that way for a while.  So what do we do?  Well, we could just close up shop and let our yards turn to dust, or we could bust out the hoses and prepare for battle.  Really folks, let’s be realistic.  This drought can’t last forever.  But until it begins to rain again, our plants are depending on us to keep them alive.  Here’s how you can help.
First, consider the water needs of newly-planted trees and shrubs.  Remember, these newcomers to the landscape are dependent on roots within the rootball (for balled & burlapped plants) or the root-mass (for container-grown plants) for water uptake and survival.  Therefore, the most important place to check water status (water need) is in the rootball or root-mass, not in the surrounding backfill soil.  Until roots grow into the backfill soil, moisture in the rootball or root-mass can be depleted very quickly.  This is why frequently irrigated trees and shrubs will establish more quickly than those receiving infrequent irrigation.  Proper frequency and amount of water needed will vary according to area rainfall, moisture-holding capacity of the soil, and the site’s drainage characteristics.  But with temperatures hovering around 100-degrees, daily irrigation may be in order especially for plants on open, exposed sites.
To properly water newly-installed landscape plants, apply water slowly near the base of the plant and over the developing root system.  Water applied too rapidly will be lost through run-off.  Two to four gallons/inch of trunk diameter is a good rule of thumb for trees.  Irrigation frequency can be reduced and the area to be watered enlarged as the root system begins to grow into the backfill and surrounding site soil.  A shallow layer (two to four inches) of organic mulch spread over the planting site will help conserve moisture in the soil.  Products like shredded bark and wood chips also will help water infiltrate the soil rather than run off.
During extended periods of drought, even large, established trees and shrubs appreciate a drink from the garden hose.  A single, large tree can transpire away more than 100 gallons of water on a typical summer day.  If your plants are showing symptoms of moisture stress (wilting, yellow leaves, and/or scorched leaves) apply water with an oscillating sprinkler set at low pressure (preferably when winds are calm) until the soil is wet to a depth of 18 inches. 

Apply water to an area at least as wide as the branch spread.  Well-established plants often have extensive root systems that extend far beyond the tips of the branches and will benefit from water applied to the soil outside the branch spread. 

Jeff Iles
Department of Horticulture
Iowa State University

 Here is the link to the webinar on the drought.  It includes information from several extension people at ISU about the drought.


Tuesday, July 24, 2012


Nick Christians
July 24, 2012

Horticulture 351, the basic turfgrass management course at Iowa State, will be offered off campus on the web this fall.  You can take it from any location around the world.  The lectures are placed on the web each night after the lecture on campus and you can watch them any time 24 hours/day.  Testing is handled through monitors at your location.  If you're interested, contact me at  515-294-0036.

The following video concerns the course content.  You can sign up at

Monday, July 23, 2012


Nick Christians
July 23, 2012

A common question the last two weeks has been "What happened to the lindens?".  The little leaf linden trees (Tilia cordata) seem to be dying from the top down.  Many of them look really bad this season.  The problem is the Japanese Beetle.  They seem to like to feed on this tree in preference to almost anything else in the landscape.

I did not realize how bad the problem was this year, until I drove down Airport Road in Ames this morning.  There are many 10 to 20 year old lindens along this road and they have been hit severely by Japanese Beetle feeding.  The damage does start at the top and then they move progressively down until they have nearly stripped the tree of foliage.  This does not seem to kill them, but it cannot be good for them, particularly with as much moisture and high temperature stress as we are getting this year.

The Japanese Beetle is a relatively new arrival here.  Up to about 5 or 6 years ago, we considered them to be an eastern pest.  But they have moved here in large numbers in the past few years.  This is by far the worst damage that I have seen here in Ames.

You can spray for them when they are actively feeding, although most people do not.  You can also use an imadocloprid (Merit) drench before they show up, although I have not had much luck with this treatment on my own linden.

The little leaf linden has been a highly desirable landscape plant in past years, but if this type of damage continues, they may lose some of their popularity.

Here are the pictures I took this morning.

Here are the culprits responsible for the damage.

Friday, July 20, 2012


Nick Christians
July 20, 2012

 The last time we had a drought like this in central Iowa was 1988.  That one was worse.  The lawns went dormant in mid-May and we did not get rain again until September.  At the field day in 1988, several lawn care specialists asked about whether they would hurt turf by treating dormant lawns.  To test this after the field day, All American Turf Beauty  applied treatments to dormant turf ranging from normal rates to rates as high a 10 times normal.  Our assumption was that we would damage turf with the high rates.

When the turf recovered in the fall, we were surprised to see no damage, even at high levels of application.  We found that there was no risk of damage from applying the treatments to dormant turf and that the treatments had a positive effect in the fall.

So, in answer to the question about putting on the August round of treatments on dormant turf, I would say go ahead.  I do not anticipate damage and will will have a positive effect when the turf does recover.

The articles below were from that time period.  They are jpg's and you will have to click on them like a picture in order to read the text.

Thursday, July 19, 2012


Nick Christians
July 14, 2012

The following is a post by John Newton, CGCS of Veenker Memorial Golf Course in Ames.  It concerns a scholarship in the name of one of his former employees who is deceased.  Derek was one of the turf students and worked at Veenker.

(From John Newton)

Thanks to the Harmon family in developing this special scholarship.   Tess Balsley (Clubhouse manager at Veenker Memorial  Golf Course) needs to be recognized for all the efforts she has put in to raise the funds for this scholarship.  Organizing promoting the Tournament with Derek’s Fraternity, Friends, tip jar for Derek and the Turf industry (especially John Ausen for supplying an annual golf club donation).  We have this year raised enough funds to endow the scholarship.  An endowed scholarship is a minimum of $25,000.00.   Thanks to all who have and continued to support this Scholarship.
The students that receive the first winners of the Derek Harmon scholarship represent the hardworking Iowa State University student.  Hard working students that are developing into young turf professionals.  The many ways they develop the skills required in the turf industry are to be good students, internships and working at Iowa State University.  (One of the things Derek was always talking about is the great experience’s he had with his internships at (Veenker, Pinehurst, Vail Colorado)
The Horticulture Turfgrass Program at Iowa State is one of the Nation’s leading Turf grass Programs.  One of the signs that tell how gifted the Iowa State Student and staff is the dominance Iowa State has had in the annual Turf Bowl competitions.  Although there is numerous good turf schools that compete in this annual event Iowa State  dominants the Turf Bowl Competition.   

Now for the winners
Kirk Hudson received a $1,000.00 scholarship, Kirk has worked at Veenker the past two school years and has done an internship at Copper Creek and is currently working at Wakonda in Des Moines.
Joel Reiker  receives a $250.00 scholarship, Joel is currently working at Iowa State Athletics in the Athletic Turf side of the industry.  Joel is doing what was part of a special project at Veenker.  A Iowa State logo painting.
Congratulations to both of these gentleman and thanks to all who have helped in donations and materials for this scholarship.

Monday, July 16, 2012


Nick Christians
July 16, 2012

The annual turfgrass field day is this Thursday, July 19.  Registration is at 8:30 and the program starts at 9.  For more details, see the Iowa Turfgrass Institute web site at

Iowa Turfgrass Field Day
July 19, 2012
Horticulture Research Station - Ames, IA
Sponsored by ITI, Iowa GCSA, ISTMA, IPLCA & Iowa State University

July 19 - ITI Turfgrass Field Day Turfgrass Research Station, Ames
Host: Dan Strey
$30 Per person
Pesticide Training available for additional $20 fee

8:00 AM : Registration with Coffee and Donuts
8:45 AM : Introduction - Registration Tent
9:00 AM : Blue and White Tours Begin
10:00 AM : Red Tour (PAT) Begins or Switch Blue and White Tours
11:00 AM : Turfgrass Insect, Weed & Disease ID Tour(must attend for PAT Credit)
12:15 PM : Lunch and visit the Vendor Trade Show


Saturday, July 14, 2012


Nick Christians
July 14, 2012

I have received some question lately on the yellow flower that is showing up in lawns in midsummer.  The plant is Bird’s-foot Trefoil (Lotus corniculatus).  In past years, it has been included in roadside mixtures in Iowa and has spread to lawn areas.  It is not unusual to see it along curb sides as in the picture below.  It is a perennial, but most people do not notice it until late June when it begins to flower.

It is a legume and has a flower similar in shape to the Pea.  Personally, I think it is very attractive.  According to an article in Wikipedia, the fresh tissue contains cyanogenic glycosides, which are toxic to humans. I have never tried to eat it, but I don’t think that it presents any danger to humans.  It is a forage,  and cattle often graze on it.

Being a clover-like broadleaf, it is controlled by most of the same broadleaf herbicides that control clover.  It is generally observed in lawns that have not been treated with broadleaf controls.  If you want to get rid of it, I would wait until fall and treat with broadleaf herbicides.  It will be gone next year.  The reason for waiting, is that these herbicides will easily damage other landscape plants at this time of year.

Bird's-foot trefoil in a curb area in central Iowa. 

Tuesday, July 3, 2012


Nick Christians
July 3, 2012

Windmill grass (Choris verticillata)   has been moving into Iowa in the last few years.  This summer I am seeing more of it than ever.  This is a spreading, warm-season weed with a light green color.  It gets its name from its distinctive seedhead that looks like a windmill.  The seedhead will detach from the plant when the seed is mature and it will roll like a tumbleweed and spread its seed to other turf areas.  It is also known as tumble windmill grass in some regions.

Roundup will kill it non-selectively, but it is a great seed producer and it will come back.  The new herbicide Tenacity (mesotrione) is labeled for it.  I have not tried this yet myself, but I hear that it works well if you are persistent.  If anyone has experience with this, let me know.

I took the pictures below this morning near Nevada, Iowa.  This is typical of where it occurs.  I generally see it along curb sides and in compacted area, although it can show up in more open turf areas.

Monday, July 2, 2012


 Nick Christians
July 2, 2012

I was in Norway and Switzerland last week for some professional meetings and was not able to post more information about the Japanese Beetles showing up in Central Iowa.  During that time, I received several e-mails about beetles.  They showed up in large numbers in the last week of June.

The first picture is from Nick May, Manager of TruGreen in Ankeny.  It shows severe feeding damage on oak.

The second one from Dan Strey at the research station.  We are seeing large numbers of adults this week.

The final picture is from a rose study next to the turf research area.  I took this today, July 2.