Why Ash Trees are valuable (and why EAB is a problem):

• Minnesota has nearly one billion ash trees, according to the MN DNR.

• Ash trees were often planted to replace American elms lost to Dutch elm disease. 

• Ash, especially black ash, is an important species to our state's lumber industry.

• Emerald ash borer, a small insect, attacks all ash species: green, white, and black.

• Basically, it's a near-extinction event for ash trees in North America because they have no natural defenses against the insect.

• EAB population is currently peaking in the Twin Cities area with the vast majority of untreated ash trees declining rapidly or already dead.

• The only defense against this invasive and deadly insect is preventative treatment by a certified arborist.

Emerald Ash Borer (EAB) History:

• Globally: EAB is from Northeastern Asia where it only attacks weak ash trees; healthy ash trees can fight off EAB.

• Nationally: It first appeared near Detroit in June 2002, though experts think it was actually here since the 1990s.

• Locally: Found in St. Paul near the U of MN campus in May 2009.

Spotting EAB Symptoms:

• Starts with the top of the tree looking thin.

• Within 2-3 years, the upper canopy is mostly dead, but you might see a flush of healthy-looking growth lower on the trunk.

• The bark in the upper parts can look splotchy, called "blonding."

• Emerging adults make the distinctive “D” shaped holes, often more visible on medium sized branches.

• Tree death usually follows quickly, about 3-4 years after the EAB attacks.

What is an Emerald Ash Borer?

• Adult insects are slender, ⅜ inch long, emerald green in color and rarely seen.

• Cream-colored larvae are found under the bark feeding on the inner bark and cambium. They are slender as well and ½ to 1½ inches long.

• Larval feeding causes “S” shaped galleries, preventing water and nutrient movement in the tree, which is what eventually kills the tree.

What Can You Do About Emerald Ash Borer: Treat or Remove Ash Trees

• Slow the spread: do not move firewood. In other words, do not take firewood to your cabin. The majority of northern Minnesota counties are under EAB quarantine because of this.

• Treat your ash trees. If you are not treating your ash trees, they will die from EAB. 

• Missing even one every-other-year scheduled treatment can lead to serious decline and possibly death of your ash tree.

• If you haven't started treating by now, it likely is too late to save your ash trees.

How Shadywood Can Help:

• We have been protecting ash trees since 2009. We are the experts!

• We offer all the latest EAB treatment options.

• Our arborists are full-time, year-round professionals who will check out your ash trees before recommending a treatment plan. 

• Removing EAB-affected ash trees is risky because their branches far more quickly than other recently-dead trees become weaker and more brittle. Our team has the training, experience, and equipment to remove these trees safely and efficiently.

• We offer full tree pruning, removal and stump grinding services. In addition, our plant health care division can care for your valuable trees, evaluating their health, creating customized health programs to keep these trees healthy and flourishing for as long as possible.

The Future of Ash Trees:

• EAB is seriously changing the look of our streets, parks, and wooded areas.

• In just a few years, ash trees will be a rare sight in Minnesota's towns and forests.

• In Northern and central Minnesota, a valuable lumber resource will be lost.

• Research and testing is being done to find ash trees that are naturally resistant

Early symptoms of Diplodia show new needle growth has died before fully expanding

Diplodia Blight

Diplodia Blight is a twig and branch canker disease caused by the fungus Diplodia Pinea. The disease primarily affects mature pine trees that have become stressed after periods of drought or poor site conditions. Austrian pine are the most severely affected while Red pine have slightly better resistance. Initial symptoms appear when new shoot growth at the tips of branches becomes stunted and turns brown. Severely affected limbs with very little green growth can become girdled by the canker, causing the entire limb to die.  

Dothistroma needle blight

Early symptoms of dothistroma shows reddish spots forming into a band that girdles the needle.

Dothistroma needle blight is a needle disease caused by the fungus Dothistroma Pini. It can affect many types of pine but Austrian Pine are the most severely affected. Symptoms first appear on fully grown needles as yellow-tan spots. The spots then form a reddish brown band that girdles the needle and the tip turns tan. By the end of the year the entire needle will turn tan. Fungal spores spread the disease from infected needles onto nearby healthy ones, repeating the disease cycle. New infection can occur multiple times per year but most commonly occurs in spring during long periods of rain.

Additional notes:

In most cases, diseased pine trees show symptoms of both diseases and the products we use provide effective control for both at the same time.  Some trees may be too tall to spray the very top (if they are above 50’ tall), but the diseases predominantly occur on lower portions of the tree, while the very top remains green and healthy. Annual spray treatments may significantly reduce these diseases but cannot cure the tree entirely.
Avoid using nitrogen based fertilizers near diseased pine trees (this includes lawn fertilizer) as nitrogen has been shown to accelerate disease development.

Here’s what we can do

Shadywood Tree Experts can help maintain your trees with the use of systemic and/or contact fungicide spray applications. When you sign up for plant health care from Shadywood, we administer the recommended protocols for disease prevention control to keep your trees healthy. With each visit, our arborists assess trees for overall health.

Additional things homeowners can do to maintain their pine trees:

Water your pine by running a hose near the trunk of the tree for a deep soaking of 1-2 hours if we do not receive adequate rain (small trees can be watered for a shorter time). Rake up and dispose of fallen diseased needles. Mulch the area beneath the tree with a wood mulch or chips. If you see anything that doesn’t look right, have your trees inspected by one of Shadywood Tree Experts International Society of Arboriculture Certified Arborists.

When severe Diplodia causes entire limbs to die

Sap bleeding from branch cankers caused by Diplodia

Apple scab (Venturia inaequalis), is one of the most common and serious fungal diseases of flowering crabapples in Minnesota. Symptoms appear as olive-colored spots on leaves and are  first seen in late May and early June. As the disease progresses into June and July, leaves yellow and begin to fall, causing crabapples to become thin. Consecutive days of cool, wet weather in April and May when leaves are immature lead to new infections.

Crabapples infected with apple scab are weakened and stressed due to the leaf loss and can be prone to more serious problems. Spraying crabapples preventatively as new leaves emerge and fertilizing on an annual basis are the best method of controlling and minimizing the impact of apple scab.

Here’s what we can do

Shadywood Tree Experts can help maintain your trees with the use of systemic and/or contact fungicide spray applications and annual fertilization. When you sign up for plant health care from Shadywood, we administer the recommended protocols for disease prevention control to keep your trees healthy. With each visit, our arborists assess trees for overall health.

Additional things you can do to maintain the health of your crabapple tree

Water trees regularly using a hose or small sprinkler for at least an hour once every one to two weeks if we do not receive adequate rain. Avoid spraying leaves directly when watering as wet leaves can promote fungal diseases. Mulch root systems when possible, using natural wood chips to protect the trunk, condition and improve the soil, and to conserve soil moisture. Rake up and dispose of fallen diseased leaves. If you see anything that doesn’t look right, have your trees inspected by one of Shadywood Tree Experts International Society of Arboriculture Certified Arborists.

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Apple scab has caused this crabapple tree to appear thin and unhealthy.

Apple scab infected leaf

Constantly spraying leaves with irrigation can cause apple scab to become worse. We have been treating the crabapple trees at this property and asked the home owner if they can have their sprinklers adjusted to avoid spraying leaves.