By Don Kissinger, urban forester, 715-348-5746, Don.Kissinger@wisconsin.gov or Paul Cigan, plant pest and disease specialist, 715-416-4920, Paul.Cigan@wisconsin.gov
Anyone with oak trees in their yards or on forested lands should avoid pruning or cutting them from April through July to protect them from oak wilt.
Sap-feeding beetle on diseased oak tree in Sawyer County.
Continue reading “Protect oak trees by pruning after July, not before”
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.
Loss of older needles on an infected spruce.
Continue reading “Severe spruce needle diseases expected in 2020”
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.
Continue reading “Prepare for the return of gypsy moths in spring”
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.
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.
Continue reading “Fighting invasives together through responsible firewood practices”
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.
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).
Continue reading “Check your trees for EAB and plan for spring”
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”
By forest health specialists Paul Cigan, Hayward, paul.cigan@wisconsin.gov, 715-416-4920 and Linda Williams, Woodruff, linda.williams@wisconsin.gov, 920-360-0665
Oak wilt has been found for the first time in Forest County and several new northern townships in 2019. These previously undocumented infections were detected using a combination of ground surveys, forester and landowner reports and aerial survey flights. This deadly fungal disease of red oaks has now been confirmed in 65 of Wisconsin’s 72 counties.
Oak wilt detection map as of January 1, 2020.
Continue reading “Oak wilt found in Forest Co. and northern townships”
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.
“The best time to prune trees that lose their leaves is during winter when the trees are dormant,” said DNR forest health specialist Paul Cigan. “Not only is it easier to see where pruning is needed when leaves are gone, but disease-carrying pests are inactive due to the cold, making pruning both more effective and less likely to invite unwanted pests.”
While pruning in winter reduces the risk of spread through beetles, Cigan pointed out that the disease can spread year-round in firewood. “Several recent oak wilt finds in northern Wisconsin, including a first-ever find in Forest County, may have been the result of infected firewood brought from areas with oak wilt,” Cigan said. “Keep oak firewood where it is cut for one year, or until the bark is naturally loose, to prevent the spread of oak wilt,” he advised.
For more information, visit DNR webpages for oak wilt and firewood.
Pruning tips
Yard trees and trees in urban settings should be pruned throughout their entire life to maintain strong structure and remove dead wood. Young trees should be pruned to establish a central trunk, proper trunk taper and good branch structure and spacing. Older trees should be pruned to remove dead and/or hazardous limbs. “Pruning should not remove more than 25 percent of the live tree crown, and the lower third of deciduous tree trunks should be free of limbs,” advised DNR urban forestry coordinator Don Kissinger. You can find more detailed, step-by-step tips for tree pruning in this DNR tree pruning publication.
Certified arborists who offer pruning and other tree care services can be found at waa-isa.org/arborists/search.asp.
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:
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.
