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Winter '22 programs seek to start the Iowa Windbreak Renaissance!

January 6, 2022 9:48 AM

Iowa needs a Windbreak Renaissance!

The Iowa wind never ceases to impress me! My recent travels across the state have made one thing clear – Iowa is in desperate need of a windbreak renaissance. Windbreaks and shelterbelts act as critical farm infrastructure – providing energy savings, livestock growth gains, timber and non-timber forest products, wildlife habitat, odor and dust control, aesthetics, and privacy. However, Iowa’s aging windbreaks are simply not functioning as they should be, due to general decline, storm damage, and insect and disease issues. Also, I “see” non-existent windbreaks in locations where they could have incredible value. To help guide recovery and resilience, consider the following tips for three common windbreak scenarios.

Scenario 1: Spotty/isolated decline or damage

Here, start by assessing the status of individual impacted trees. Snapped or split stems and/or loss of >50% of the canopy may warrant removal. Consider, however, that interplanting or replacement of individual trees will be tough, as most Iowa windbreak species (especially conifers) are shade-intolerant (i.e., they don’t grow well in shade). Assess the size and spacing of the residual trees and gaps, and ask yourself whether neighboring trees have capacity to fill the voids. If so, removal of damaged trees and proper pruning of residuals to prevent disease and decay may be the best strategy.

Scenario 2: Large gaps, row additions needed

If large gaps exist (or will be, following removals), functionality is severely compromised (Photo 1). In this scenario, neighboring trees will not be able to fill gaps, and it’s time to consider adding new rows. Number of row additions will depend on current windbreak design and your objectives. Often, folks decide to keep residual large trees for aesthetics and structural diversity, then remove once new rows have attained functional height and crown closure.  

Iowa windbreak with large storm-damage gap, resulting in reduced functionality.

Photo 1. Growth from residual trees will be unable to fill large gaps such as this. Situations such as these may warrant addition of new rows to restore functionality. Photo credit Mark Vitosh, IDNR.

Scenario 3: Complete replant/establishment of new windbreak

In many cases, damage or decline is so severe that starting over from scratch is required. Design (e.g., number of rows, spacing) and species selection will depend heavily on your site conditions and objectives, thus no cookbook recipe exists. However, it is essential to match species to soil and site conditions. Selecting the right species will encourage a long-lived, vigorous, and functional windbreak. Second, go for species diversity! Windbreaks comprised of one or two species are more vulnerable to insects, disease, storms, and other stressors. Monocultural planting of non-native blue, white, and Black Hills spruce, for example, has led to widespread loss of functionality within Iowa windbreaks (Photo 2). Selecting conifers for Iowa windbreaks is tough, as our state has only a handful of native evergreens. Conifers that perform best in Iowa windbreaks include: eastern redcedar and white pine (both native to Iowa), and northern white cedar, Norway spruce, and white fir (all non-native to Iowa, but hardy).    

Non-native spruce in severe decline due to needle cast fungus.

Photo 2. Non-native spruce in severe decline due to needle cast fungus. Non-native conifers like blue, white, and Black Hills spruce, frequently exhibit low vigor and are prone to disease issues. Photo credit ISU Plant and Insect Diagnostic Clinic (PIDC).

Lastly, consider wildlife and pollinators during your design and species selection. Incorporating rows of native shrubs and hardwood trees with varying mature sizes will add critical structural diversity, cover, and food to benefit a range of species. In working landscapes, windbreaks often represent invaluable oases of critical habitat.   

Timing and Resources

As spring is the recommended season to establish conifers, late summer through winter is the prime planning period for windbreak renovation and establishment. Natural Resources Conservation Service (NRCS) staff provide windbreak renovation and establishment technical service, and should be an initial point of contact. Cost share programs exist as well, notably the Environmental Quality Incentives Program (EQIP) and the Resource Enhancement and Protection (REAP) program. Professional foresters with the Iowa Department of Natural Resources, as well as private forestry consultants, are other valuable resources. Get with these pros and start the renaissance!

Additional resources may be found on the ISU Extension Forestry website, and by viewing a recent CropsTV! woodlands and windbreak recovery video.

Four “Windbreak School” programs will be held in-person across the state this winter - three Crop Advantage Series events: Ankeny (1/12), Cedar Falls (1/13), and Atlantic (1/20), and a more in-depth workshop in Tama County on 2/8 (free event, open to all). If unable to attend in person, watch for the forthcoming CropsTV!  “Windbreak School” webinar that will be available in late winter on our archived video page. Check the “Upcoming Forestry Events” page on the ISU Extension Forestry website for details on this series, and other Extension Forestry events.

Windbreak School: Establishment, Management, Renovation workshop

Tuesday, February 8, 2022 - 6:30pm to 8:30pm

Iowa is in desperate need of a windbreak renaissance. Windbreaks and shelterbelts act as critical farm infrastructure – providing energy savings, livestock growth gains, timber and non-timber forest products, wildlife habitat, odor and dust control, aesthetics, and privacy. However, Iowa’s aging windbreaks are simply not functioning as they should be, due to general decline, storm damage, and insect and disease issues. Read more about Windbreak School: Establishment, Management, Renovation workshop

Windbreak School - Calhoun County

Friday, September 9, 2022 - 9:00am to 12:00pm

This free outdoor event will provide opportunity to network one-on-one with forestry and natural resource professionals. Speaking topics will address windbreak establishment, maintenance, and renovation. This event is open to all Iowans, regardless of county of residence.

Pre-registration requested by 9/6 to guarantee your meal (see flyer for instructions).

See this link for flyer and registration instructions. Read more about Windbreak School - Calhoun County

Windbreak School - Cerro Gordo and Mitchell counties

Thursday, September 8, 2022 - 9:00am to 12:00pm

This free outdoor event will provide opportunity to network one-on-one with forestry and natural resource professionals. Speaking topics will address windbreak establishment, maintenance, and renovation. This event is open to all Iowans, regardless of county of residence.

Pre-registration requested by 9/6 to guarantee your meal (see flyer for instructions).

Click here for flyer, topics, and pre-registration instructions. Read more about Windbreak School - Cerro Gordo and Mitchell counties

Tree Farmer of the Year Fall Forestry Field Day

Thursday, September 29, 2022 - 9:00am to 2:30pm

Join us at an exceptional Butler County property, as we announce the 2022 Iowa Tree Farmer of the Year as part of this annual forestry field day. Learn practical and science-based forest stewardship techniques including reforestation and tree planting, wood turtle habitat management, black walnut crop tree release, CRP seeding (pollinator and prairie), and hear current timber market updates.

This event will feature a live logging demonstration! Read more about Tree Farmer of the Year Fall Forestry Field Day

Consider native deciduous trees and shrubs for windbreaks

November 28, 2022 9:23 AM

Iowa’s windbreaks have lost functionality

Windbreaks are critical farm infrastructure, providing Iowa producers with crop yield increases, livestock protection and gains, reduced soil erosion, diversified income sources, energy savings, wildlife habitat, recreation, and aesthetics (Photo 1). As I travel the state, however, I frequently observe windbreaks with a complete loss of functionality. This large-scale loss is the result of many factors, including windbreak age, lack of proper maintenance, and impacts from extreme storm events and drought. At the core, these issues are exasperated by our historic reliance on a limited number of conifer species. Many windbreaks I’ve observed with near-zero functionality are comprised of a single, non-native, conifer species (e.g., blue spruce). We all know that native tree species perform best in Iowa’s variable climate. However, Iowa only has a handful of native conifers, and portions of Iowa have only one – eastern redcedar. In contrast, Iowa does have an extensive assemblage of native deciduous trees and shrubs – a large enough list to cover all of Iowa’s sites and geographic regions. To maximize windbreak functionality and longevity, it’s time we do away with our overwhelming reliance on conifers, and start considering deciduous trees and shrubs for Iowa windbreaks!

Polk County windbreak with deciduous species incorporated for income diversification.

Photo 1: This multi-purpose windbreak acts as an asset to a rotational grazing operation in Polk County, Iowa. This windbreak was established using both coniferous and deciduous species, to acheive goals of livestock protection and income diversification from posts, fuelwood, sawtimber, and nut crops. 

Why Deciduous?

The year-round foliage and upright form of conifers make them nearly unbeatable for wind velocity reduction and privacy. Considering this, native (e.g., eastern redcedar) and non-native but hardy (e.g., Norway spruce) conifers should remain as significant components of our windbreaks. However, with diversity being the key to windbreak resiliency, functionality, and longevity, being open to deciduous trees and shrubs greatly increases our species selection options on a wide range of soils, sites, and geographic locations – areas where conifers have historically struggled. Wet, dry, clayey, sandy, and everything in between – there’s a list of native deciduous trees and shrubs that will work nicely on your site.

 

Deciduous trees can deliver on winter wind velocity reduction, it just takes more of them. In general, it would take approximately five rows of leaf-droppers to match the wind protection provided by a single row of conifers. For faster protection, you may plant stock at a tighter spacing. However, you must be diligent to thin at the appropriate time (when crowns begin to touch) to ensure long-term vigor. In addition, it may be valuable to consider trees that exhibit some degree of marcescence – also known as winter leaf retention (Photo 2). While not as dense as conifer foliage, the retained leaves do add winter wind reduction value, privacy, beautification, and wildlife benefits. Notably species that exhibit marcescence include oaks, ironwood, and witch hazel.

 

Incorporation of a diversity of native deciduous species also provides a multitude of compound benefits to Iowa’s farmers – notably, potential for income diversification and wildlife and pollinator habitat. In an example from Polk County (Photo 3), a rotational grazing operation used a solely-deciduous windbreak to protect a livestock winter feeding area. As added benefits, the producer plans to sustainably harvest sawtimber, fence posts, fuelwood, and nuts from this planting. Addition of shrubs on the windward and leeward side of windbreaks may aid in wind lift, as well as provide diverse structure (e.g., smaller, multi-stem) that may be utilized by a wide range of wildlife species. Selecting a range of shrubs (and trees for that matter) that bloom at different times will act to extend the availability of critical fuel for pollinators throughout the growing season. Not to mention delicious edible fruits for you!   

A swamp white oak exhibiting marcescence.

Photo 2: A number of species, such as this swamp white oak (Quercus bicolor), exhibit degrees of winter leaf retention, known as marcescence.

Resources and Next Steps

Selecting the right deciduous tree and shrub species to match your site conditions AND achieve your windbreak functionality goals is an important decision. Your first stop should be your county USDA Service Center. From there, Natural Resources Conservation Service (NRCS) staff will work with you to design your windbreak, and select the appropriate species to achieve your goals. Private forestry consultants may also be able to assist in this matter. Check out the ISU Natural Resources Stewardship Contacts webpage to find professionals that serve your county.  

 

For a chance to learn more on windbreaks, in an in-field setting, check out the Windbreak School (WBS) program – hosted by Iowa State University Extension, the Iowa Department of Natural Resources, and NRCS. Check the ISU Extension Forestry Upcoming Events webpage frequently for program dates and locations (note, WBS often occurs in late summer, to allow for ample time to plan and prepare for spring plantings). Lastly, check out our Windbreak School and Derecho Response for Woodlands and Windbreaks YouTube videos. So, let’s start moving away from our conifer reliance, and start appreciating deciduous species for the diverse benefits they may provide to Iowa’s farmers!

A multi-purpose windbreak in Polk County, created using solely deciduous species.

Photo 3:  This solely-deciduous windbreak in Polk County serves to protect a winter cattle feeding area by reducing wind velocities and directing snow deposition away from the site. In addition, incorporation of valuable hardwood species (e.g., oak, walnut) may offer sustainable income potential. Note 5+ rows in design.