Statewide Forest Health

Severe spruce needle diseases expected in 2020

By Bill McNee, DNR forest health specialist, Oshkosh, bill.mcnee@wisconsin.gov, 920-360-0942

Wet weather in 2019 created ideal conditions for Rhizosphaera kalkhoffii and other needle cast fungi to infect spruce needles. Since it takes about a year for the needles to show symptoms, heavy and widespread needle diseases are expected to be seen on spruce trees in 2020. These diseases cause older needles to turn brown and fall off prematurely, making the tree look ratty and sparse. Lower branches and the interior of the tree are most affected by needle cast diseases. Current-year needles do not show symptoms but may become infected.

Lower branches of an infected spruce tree have lots of missing needles and some that are browning.

Loss of older needles on an infected spruce.

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Prepare for the return of gypsy moths in spring

By Bill McNee, DNR forest health specialist, Oshkosh, bill.mcnee@wisconsin.gov, 920-360-0942

Gypsy moth eggs are expected to start hatching as temperatures warm in the next few weeks. Now is a great time for homeowners to check their trees for egg masses and treat or remove any that are found. Removing the egg masses now will help protect trees from defoliation and reduce future caterpillar populations.

Gypsy moth larvae hatching from egg masses on an outdoor bowl.

Gypsy moth larvae hatching from egg masses on an outdoor bowl.

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Nominations Open For “Invader Crusader” Awards

By Tara Bergeson, DNR invasive species team leader, 608-264-6043, Tara.Bergeson@wisconsin.gov

Nominations are being accepted through March 23, 2020 for “Invader Crusaders.” These awards go to individuals, groups and organizations who made outstanding contributions in 2019 to prevent, control or eradicate invasive species that harm Wisconsin’s native wildlife and wetlands, forests, prairies, lakes and rivers.

The Wisconsin Invasive Species Council is seeking nominations for exemplary efforts at addressing issues surrounding terrestrial and aquatic invasive plants and animals. The awards will be presented in both volunteer and professional categories.

To submit a nomination, download and fill out a nomination form available on the Wisconsin Invasive Species Council’s Invader Crusader webpage. Email the completed form to invasive.species@wisconsin.gov by March 23.

A panel of Wisconsin Invasive Species Council members will review the nomination materials and select the award winners. All nominators and winners will be notified by mid-May 2020.

Recipients of the awards will be recognized at an awards ceremony on June 11 at Olbrich Botanical Gardens in Madison.

Invasive species are nonnative plants and animals that cause great ecological, environmental or economic harm, and some can even affect human health. Once an invasive species becomes established in an area, it can be difficult to control. The most important action Wisconsinites should take is to avoid moving invasive species or the materials that might harbor them to new places.

To learn more about what you can do to stop the spread of invasive species, visit the DNR invasive species webpage.

Fighting invasives together through responsible firewood practices

By Marguerite Rapp, forest health communications specialist, marguerite.rapp@wisconsin.gov, Andrea Diss Torrance, invasive insects program coordinator, andrea.disstorrance@wisconsin.gov, and Tim Allen, DATCP forest pest program coordinator and nursery inspector, timothy.allen@wisconsin.gov, 715-891-8158

This time of year, many Wisconsinites warm up with firewood, whether that’s in a wood stove for the home or a bonfire with family and friends. While firewood is one of the most sustainable heat sources available, the forests that produce it are threatened when firewood infested by invasive species is moved long distances. Fortunately, we can reduce this threat together through responsible use, movement and sale of firewood and wood products.

Man loads firewood into arms from back of truck. Continue reading “Fighting invasives together through responsible firewood practices”

Check your trees for EAB and plan for spring

By Bill McNee, forest health specialist, Oshkosh, bill.mcnee@wisconsin.gov, 920-360-0942

The cold winter months are a great time to think about emerald ash borer and whether ash trees in your yard are suitable for treatment. The pest is currently the most damaging threat to trees in Wisconsin, killing more than 99 percent of the ash trees it infests.

Two side-by-side images depicting different stages of flecking on ash trees - on left side is light flecking in the upper canopy of a tree, on the right side is more severe flecking that extends down the trunk of the tree

Woodpecker flecking is an early sign of EAB infestation when it appears in the tops of trees (left). As the infestation progresses, flecking continues down the trunk and into lower parts of the crown (right).

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Upcoming forest health events

Learn more about forestry and forest health issues with these upcoming events in February and March! We link to conference brochures and webpages where you can find detailed information, including registration prices and deadlines where applicable. Continue reading “Upcoming forest health events”

Protect your trees from disease by pruning when they have no leaves

By Paul Cigan, forest health specialist, Hayward, paul.cigan@wisconsin.gov, 715-416-4920

With the new year upon us, healthy lifestyle habits are sure to be on many people’s minds as they plan for changes in diet and exercise. The new year is also the perfect opportunity to make healthier choices for trees! Winter is the ideal time for tree pruning while avoiding harmful, disease-carrying pests such as the tiny beetles that carry oak wilt from one tree wound to another.

Woman pruning a tree with no leaves on it.

Pruning during winter is less likely to invite unwanted, disease-carrying pests like the beetles that carry oak wilt from one tree to another. Credit: sasapanchenko.

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2019 Forest Health Annual Report now available

Forest health annual report now available for 2019.

The Forest Health Annual Report summarizes notable impacts for that year of pests, diseases and weather on the health of Wisconsin’s forests. The report is a collaborative product created by DNR forest health specialists from around the state. It outlines the damage and spread of both native and invasive pests and diseases during that year and puts these into context of observations from previous years. Management programs and their results are also described. Highlights from the 2019 annual report include:

  • Dramatically increased decline and mortality from emerald ash borer in southern WI
  • New county and township detections of oak wilt
  • Precipitation record and major storm damage
  • Summary of state nursery studies on Diplodia sapinea, galls on jack pine seedlings, and testing new fumigants to replace methyl bromide

This year’s annual report is available on the DNR forest health homepage. Previous annual reports, including historical reports dating back to 1951, are archived and available upon request. Contact your local forest health specialist if you’d like digital copies of any archived annual reports.

New map illustrates damage from EAB

Forest health staff recently produced a map that highlights a gradient of damage from southeastern to northwestern Wisconsin, which roughly corresponds to the length of time EAB has been present in these parts of the state. Whatever the level of damage, homeowners and landowners should consider treating healthy ash, including trees that have responded well to previous treatments, or removing declining, untreated ash before they become hazardous and even more costly to remove.

County-level map of damage from EAB to ash tree populations in 2019

County-level assessment of damage to ash population by emerald ash borer, 2019.

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Invasive plants, ticks and you

Most people are familiar with the impacts of invasive plants to natural areas, but did you know that invasive plants can be hazardous to human health? Did you also know there is a new app available to learn about tick activity near you and help researchers by recording your own tick encounters?Forested setting with tree in foreground and sign attached to tree that says beware of ticks. Continue reading “Invasive plants, ticks and you”