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Extension > Yard and Garden News > April 2013

Monday, April 1, 2013

April 1 2013 Issue

In this month's issue:

New Options to Get Your Yard and Garden News

Lawn care: spring floods and drought ....really?

New Sightings of Invasive Insect Pests

New Options to Get Your Yard and Garden News

Sam Bauer, Extension Turfgrass Educator

Greetings Yard and Garden News Readers!

As we write this, March is quickly coming to a close, yet we're still looking at snow on the ground across much of the state. What an unbelievable start to spring. Mother Nature has really shown us over the last couple of years that there really is no such thing as normal. But, weather patterns are not the point of this article, rather we would like to inform you about some positive changes that have happened with the Yard and Garden News over the last month.

No, this is not the time to panic if you enjoy the current format and the way that you receive and read our publication. None of that will change. We've simply added more ways for you to access the information in a timely manner, and we're utilizing more platforms for you to learn from our educators.

We will continue to email out all of the articles bi-monthly (growing season) or monthly (off season) if you are a subscriber. However, when more critical time sensitive issues arise, we will be posting those articles immediately. The first article to be posted in this fashion was Jeff Hahn's "New Sightings of Invasive Insect Pests." We feel that articles such as this one are important to get to you as soon as possible. For this reason we have added Facebook and Twitter to our arsenal.

Photo 1: Y&G Facebook

If you are a Facebook user, you can find us at "University of Minnesota Garden Info." By "liking" our Facebook page you will start to receive our status updates and posts in your personal news feed. We will have similar information here as on the Yard and Garden News, but you might expect to find more frequent short posts. Please feel free to leave comments and/or questions to any of the posts, as we will have an administrator managing the site to make sure that you received timely and valuable feedback.

For you Twitter users, we have a Twitter account as well. You can find us by searching for the handle @UMNgardeninfo. In January's issue of Yard and Garden News I wrote an article regarding the basics of Twitter and encouraged many of you to join Twitter. In fact, we even held a drawing for a free membership to the Minnesota Landscape Arboretum for one lucky person that followed some detailed and particular instructions. Congratulations to Tom Wawra for winning this drawing!

Photo 2: Y&G Twitter

We always welcome any comments regarding these changes. You can comment by reaching out to us on our Facebook page, Twitter account, or by emailing us at: You will hopefully find some value in these new applications, and we look forward to hearing from you.

Happy Horticulture,

University of Minnesota Extension Educators

Lawn care: spring floods and drought....... really?

Sam Bauer, Extension Turfgrass Educator

Hooray! It's finally time to start thinking about home lawn care again.  Last fall we were stressing the importance of maintaining moisture levels in your lawn amidst one of the worst droughts in Minnesota's history.  In case you've forgotten, the months of August through November alone saw an eight inch precipitation deficit in the Twin Cities area.  This translates to approximately 70% below average precipitation for the fall period.  Many other areas of the state, mainly northwestern and southern Minnesota, were in a much worse situation.

Photo 1: Winter precipitation

Currently, 67 percent of Minnesota is in Extreme Drought or Severe Drought according to the University of Minnesota Climatology Working Group (Spoden, 2013).  Fortunately, total precipitation for 2013 is so far above average.  The climatology map on the left shows precipitation departures from normal for the first of the year until now.  The northwest region of the state has received as much as 2.5 inches of precipitation above normal.  Question: will this help to replenish soil moisture levels?  The simple answer is, well, not exactly.

Currently soils are frozen.  Soil frost depths generally range from 0 up to 60 inches in Minnesota soils, and this takes time to thaw out in the spring.  This generally means that precipitation falling right now (on mostly frozen soil) does not get absorbed into the soil, but rather promotes the flooding that we experience every spring.  Even during slow spring thaws, the surface moisture melt will precede the defrosting of our soils, in which case most of the surface moisture will run off.  This means there is potential for spring flooding AND continuation of drought conditions.  Depending on your location in the state, you may need to consider preparing for flood or drought, possibly both.

Flooded Lawns

Last spring we saw flooded lawns in many areas of the state.  Additionally, the floods near Duluth in June left many homeowners with silt covered turfgrass in need of repair.  If your home is in close proximity to any body of water, especially some of our main rivers like the Mississippi or the Minnesota, this may be nothing new to you.  However, it's always good to be prepared for worst case scenario situations.

Randy Nelson

Photo 2: A spring flooded lawn - remedies - remove silt & debris, aerate, interseed

Consider these tips to help reduce the damage and recover from flooding:

  • Sandbag high risk turf areas to reduce the extent of flooding and buildup of silt
  • Remove all debris and silt from smothered turf areas as soon as possible
  • Smothered turf should be aerated to allow the exchange of oxygen and encourage new growth
  • Avoid planting perennial ryegrass, as it is generally less tolerant of flooding than other turfgrass species.
  • Consider completely renovating lawns that are not easily repaired

For more information on repairing spring flooded lawns, please see this Yard and Garden News Update from retired Extension Turfgrass Educator Bob Mugaas:

 Drought Stressed Lawns

It seems odd to be discussing both flooded and drought stressed lawns in the same article, but really this is the situation that we are potentially facing this spring.  Those of you that maintained sufficient soil moisture levels through supplemental irrigation last fall will be in a much better situation than those that chose to not water.  In many cases, even the slightest effort to provide your turfgrass with some moisture would have paid big dividends.  We also discussed dormant seeding last fall, which can be great practice to improve the quality of your lawn the following spring.  If you failed to irrigate and/or dormant seed, unfortunately you might have a lot of work to do this spring.

Sam Bauer

Photo 3: A lawn left to go dormant last fall

Proper irrigation practices will be critical to promote a healthy lawn this spring.  Consider these irrigation tips for drought stressed lawns:

  • Irrigate during the early morning hours to reduce the leaf wetness period which is prolonged by night watering. Avoid daytime irrigation, which has the potential to evaporate quickly and be blown off target
  • Water sufficiently to replenish soil moisture
  • Monitor daily soil moisture loss through evapotranspiration and replace only what is lost.  Follow this link for evapotranspiration values in your location
  • Make seasonal adjustments to your irrigation system or watering schedule based on rainfall and temperature.  In general, spring and fall watering should be heavy and infrequent, and summer watering should be light and frequent
  •  Measure the depth of water put out by your irrigation system or sprinkler over a certain time period. This will be important in determining how long to run your irrigation cycle

For more information on proper irrigation practices, please follow these links:

Home irrigation systems:

Lawn watering practices:

Watering lawns and turf:

As always, call or email with questions: or 763-767-3518

Spoden, Greg. 2013. Drought Conditions: Update March 7, 2013. Minnesota Climatology Working Group. Online resource:

New Sightings of Invasive Insect Pests

Jeffrey Hahn, Asst. Extension Entomologist

Two invasive insect pests, emerald Ash Borer (EAB) and brown marmorated stink bug (BMSB) were found in new locations during March.

Jeff Hahn

Photo 1: Emerald ash borer

EAB was discovered in Roseville (Ramsey County) on March 19 at the intersection of Snelling Ave. and Highway 36 by an arborist. The Minnesota Dept. of Agriculture (MDA) was contacted and after inspecting the tree was able to confirm one ash was infested by EAB. They also found three nearby trees that exhibited EAB symptoms and is suspected to be infested. MDA and the city of Roseville will conduct additional surveys in the area to verify the extent of the infestation. So far, the infestation only appears to be a few years old and likely represents a new pocket of infestation.

Despite this new infestation, EAB has still been confirmed in only four counties in Minnesota. In addition to Ramsey County, EAB has also been identified in Hennepin, Winona, and Houston Counties. You can use this MDA map to see where EAB has been confirmed in Minnesota.  For more information on EAB, see the Extension emerald ash borer page.

Jeff Hahn

Photo 2: Brown marmorated stink bug

In early March, BMSB was confirmed in Duluth (St. Louis County). A student working in the University of Minnesota Duluth insect collection found a stink bug that looked suspiciously like a BMSB. The specimen was brought to the attention of the collection's curator. She e-mailed pictures of the specimen to entomologists at the MDA and the University of Minnesota. The entomologists at both institutions confirmed the specimen was indeed BMSB. The insect had been originally collected in January, 2011, inside a home in Duluth.

So far, BMSB is not very common in Minnesota and all of the specimens of this insect have been discovered in homes during winter. The Duluth find is the furthest north this insect has been found in Minnesota. BMSB has been found primarily in the Twin Cities area (Anoka, Carver, Chisago, Dakota, Hennepin, Ramsey, Washington Counties) as well as in the southeast corner of the state (Winona County). For more information on BMSB, see the MDA fact sheet.
If you believe you have discovered an insect that is a brown marmorated stink bug or a spotted wing drosophila report it to the Minnesota Dept. of Agriculture at 888- 545-6684 or
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