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How Do Trees With Purple Leaves Photosynthesize?

Posted on by janness

By Emma Kimball, DNR Urban Forestry Assessment Technician Intern

Crimson King Norway maple leaf. / Photo Credit: Van Wilgen’s Garden Center

Trees come in all shapes and sizes, but did you know they also come in all sorts of colors as well?

You may think about autumnal colors, but there are varieties of common trees with leaves that retain a purple hue from spring to fall. Trees with purple leaves such as copper beech (Fagus sylvatica ‘Purpurea’), purple catalpa (Catalpa x erubescens ‘Purpurea’) and the Crimson King cultivar of the ever-popular Norway maple (Acer platanoides ‘Crimson King’) are a gorgeous contrast to the foliage of green trees, offering aesthetic diversity to the landscape.

But how is it even possible for a tree to exist that doesn’t have green leaves? Continue reading “How Do Trees With Purple Leaves Photosynthesize?” →

Veteranization: Why Would You Age Trees On Purpose?

Posted on by janness

By Casey Czerwonka, DNR Urban Forestry Assessment Technician Intern

It’s not every day that you learn about something that goes against your instincts that’s actually a good thing. When I read about British foresters purposefully “aging” young trees with chainsaws, I thought that was odd because usually, we’re trying to improve the longevity of our trees, not speed up the clock. Why might someone want older trees faster? For the habitat, of course! Continue reading “Veteranization: Why Would You Age Trees On Purpose?” →

Hydrate Your Trees As Well As Your Body!

Posted on by janness

By: Kevin Sayers, sayersk@michigan.gov or 517-582-3209 or Lawrence Law, LawL1@michigan.gov or  313-316-4137

boy watering a spruce tree

Photo Credit: Wisconsin DNR

You don’t go anywhere in summer without your water bottle, right? In hot weather, your trees may need a drink, too, especially if they’re recently planted.

“When it’s hot and dry outside, your trees may suffer if they are not getting at least an inch of rain each week,” said Kevin Sayers, Urban and Community Forestry Program manager with the Michigan Department of Natural Resources. “Watering your trees during hot, dry spells can go a long way toward keeping them healthy.”

Deciduous trees – those that lose their leaves in fall – show drought stress through curling or drooping leaves. Leaves may “scorch,” or turn brown at the edges, fall off early or exhibit early fall color. Evergreen needles may turn yellow, then red or brown. Continue reading “Hydrate Your Trees As Well As Your Body!” →

DNR Participates In Beech Leaf Disease Detection Survey

Posted on by akabelowsky
Map of Wisconsin

A Wisconsin map showing results of a beech leaf disease survey that ran from 2023 to 2026. / Graphic Credit: Wisconsin DNR

By Art Kabelowsky, DNR Forest Health Communications, Fitchburg;
Arthur.Kabelowsky@wisconsin.gov; 608-335-0167

To date, there have been no confirmed discoveries of beech leaf disease (BLD) in Wisconsin landscape, and we are on the lookout for this disease.

The disease is primarily found on American beech (Fagus grandifolia) but can also be found on ornamental species like European, Oriental, and Chinese beech (F. sylvatica, F. orientalis, and F. engleriana). Although it has not yet been found in Wisconsin, recent discoveries of the disease in Michigan and other states highlight the continued importance of monitoring BLD’s expansion.

Continue reading “DNR Participates In Beech Leaf Disease Detection Survey” →

Avoid Ash Trees When Scouting For Deer Stand Locations

Posted on by akabelowsky
A hunter climbs into a tree stand.

A hunter prepares to safely climb into a tree stand. Hunters are advised to stay away from ash trees when choosing a tree to use for their stand, due to the possibility of hidden damage to the tree due to emerald ash borer. / Photo Credit: Wisconsin DNR

By Wisconsin DNR

As deer hunters begin to scout for suitable tree stand locations, the Wisconsin Department of Natural Resources (DNR) warns hunters to avoid placing their deer stands in or near ash trees.

That’s because of the scourge of emerald ash borer (EAB), which has been confirmed present in all 72 Wisconsin counties. It has already left most ash trees in the southern half of Wisconsin dead or dying, along with many in Door County and the Mississippi River counties.

Continue reading “Avoid Ash Trees When Scouting For Deer Stand Locations” →

Tips For Identifying Asian Longhorned Beetle And Lookalikes

Posted on by akabelowsky
Closeup of female Asian longhorned beetle.

A female Asian longhorned beetle has a shiny appearance, bright spots and black-and-white striped antennae. / Photo Credit: Bugwood.org

By Michael Hillstrom, DNR Invasive Forest Pest Coordinator
Michael.Hillstrom@wisconsin.gov

More than 300 species of longhorn beetles inhabit the Midwest. The invasive Asian longhorned beetle (ALB) is not yet one of them, with no Wisconsin populations reported.

But ALB’s potential for damage is great enough that state agencies are asking members of the public to be on the lookout for the insect — and to avoid being confused by a relative lookalike.

Continue reading “Tips For Identifying Asian Longhorned Beetle And Lookalikes” →

Species Spotlight: Japanese Stilt Grass

Posted on by akabelowsky
Wide view of a patch of Japanese stilt grass.

A dense patch of Japanese stilt grass growing within a forest. / Photo Credit: Wisconsin DNR

By Carter Hellenbrand, Invasive Plant Field Specialist, Fitchburg;
Carter.Hellenbrand@Wisconsin.gov

Note: This is the fourth installment in the Forest Health News “Invasives Spotlight” series, a monthly series of Forest Health News articles.

What has stilts, is green in the summer and reddish-purple in the fall? Japanese stilt grass!

Continue reading “Species Spotlight: Japanese Stilt Grass” →

Pine False Webworm Uncommon In Wisconsin

Posted on by akabelowsky

Messy webbing filled with frass (droppings) and pieces of needles are signs of pine false webworm feeding on this young white pine. The arrow points to a pine false webworm larvae. / Photo Credit: Wisconsin DNR

By Linda Williams, Forest Health Specialist, Woodruff;
Linda.Williams@wisconsin.gov, 920-360-0665

Pine false webworm (Acantholyda erythrocephala) is not a very common insect in Wisconsin, though it is present. They prefer to feed on white pine in Wisconsin, though reference materials say they will also feed on red pine, jack pine and Scotch pine.

Damage was reported as “minor” in the central part of the state from 1953 to 1961. Later, in 1995, 1997, 2002, 2004 and 2006, it was once again observed as a minor pest feeding on red or white pine in the central part of the state, particularly Portage, Waupaca and Waushara counties. In 2024 and again this year, a few scattered young white pine were observed being significantly defoliated in Oneida and Vilas counties.

Continue reading “Pine False Webworm Uncommon In Wisconsin” →

Japanese Beetle Populations Still Building In The North

Posted on by akabelowsky
Beetles feeding on a basswood leaf.

Japanese beetles defoliating a basswood leaf. / Photo Credit: Wisconsin DNR

By Linda Williams, Forest Health Specialist, Woodruff;
Linda.Williams@wisconsin.gov,  920-360-0665

The Japanese beetle (Popillia japonica) is an invasive insect that feeds on many plant species. The adult beetles “skeletonize” leaves by eating the material between the veins.

Adult Japanese beetles feed on the flowers and leaves of more than 300 plant species, including trees, shrubs and herbaceous plants. Forest trees can be defoliated, with open-grown or edge trees suffering the highest defoliation rates.

Continue reading “Japanese Beetle Populations Still Building In The North” →

Forest Health Staffers Plan Public Appearances

Posted on by akabelowsky
Two DNR workers discuss tree issues in the forest.

Alex Hornung, Wisconsin DNR Forest Health specialist for Central Wisconsin, discusses the tree disease phomopsis with Chief Forester Heather Berklund during a site visit near Minocqua in July 2026. / Photo Credit: Wisconsin DNR

By Art Kabelowsky, DNR Forest Health Communications, Fitchburg;
Arthur.Kabelowsky@wisconsin.gov or 608-335-0167

Alex Hornung, the Wisconsin Department of Natural Resources Forest Health Specialist for Central Wisconsin, will discuss oak wilt biology at a workshop this month.

Hornung will take part in a Wisconsin Forestry Center/Wisconsin Natural Resources Foundation workshop on oak wilt biology and management, focused on information for landowners and the public. The discussion will take place from 1 to 3:30 p.m. Tuesday, Aug. 18, at Schmeeckle Reserve, 2419 N. Point Drive, Stevens Point. She will be joined by Dr. Holly Petrillo, Professor of Forestry at the University of Wisconsin-Stevens Point.

Continue reading “Forest Health Staffers Plan Public Appearances” →