Mice & Voles

Rapid Decline of Tree or Shrub

If a tree or shrub suddenly turns up dead or is rapidly declining, there may be many possible causes. The mystery will not be solved until the tree or shrub is under close observation. One possible culprit, a situation, which is becoming more noticeable, is a small mammal chewing on the tree and disrupting nutrient flow.

Mammal Chewing

Mice, voles and other small mammals can end up chewing on trees and shrubs when food is scarce. The small mammals feed on the vascular tissue of the tree, the vein system, which transports water and nutrients. If the vein system is disrupted, it can cause the canopy to die back. Often, chewing damage occurs where the trunk meets the ground, or the root flare. If the root flare is hidden by various ground covers, it can serve as protection for small mammals. Mice and voles can also hide out in low growing shrubs and eat away at stems and twigs. Our arborists were called out on several sites this year to check out trees and shrubs in decline. On several occasions, the trees were surrounded by myrtle, ivy, or pachysandra. The ground cover was pulled away exposing a ring of feeding damage around the trunk.

Let ITS Help

Avoid this by not allowing ground covers to encircle a tree. Keep it pulled back from the trunk at least a foot. Critters are less likely to feed on the live tissue if they do not have cover. Also, monitor your landscape throughout the winter, which is when food for small mammals is scarce. We offer winter monitoring visits where our technicians come out in December or February to check the landscape. If you’re interested in learning more about this or if you would like a free quote for winter monitoring visits, please call our office at (616) 301-1300 extension 118 to schedule an appointment with one of our certified arborists.

Oak Wilt

Oak Wilt Scenarios:

  1. This past July, Integrity Tree Services received a phone call from a customer requesting one of our arborists to have a look at their red oak tree.  She informed us the mature red oak had been pruned in late May, and suddenly it was rapidly dropping leaves.  This is a sign of oak wilt.
  2. A customer called last September wanting his black oak tree examined. A storm had come through his neighborhood and broke a massive limb off the tree.  He was very knowledgeable on oak wilt and knew the situation was precarious.  We were able to save the tree.

Oak wilt (Ceratocystis fagacearum) is an infectious fungal disease, which causes rapid death in oak trees and in certain oak families, in a matter of weeks. It can be transmitted by sap beetles (Nitidulidae) as well as oaks sharing roots underground, commonly called root grafts (Brown-Rytlewski, 2007). Also, it may occur when an oak is pruned in the spring or summer months.

During the warm months of the year, sap beetles are actively feeding on tree sap. The beetles find their meals by their strong sense of smell and are lured in, particularly to the smell of sap from a freshly cut oak (Johnson & Lyon, 1987). If an oak is pruned during the spring or summer months of the year, it is an open invitation for beetles potentially carrying fungal spores. Once a beetle finds a fresh wound, it can contaminate a healthy oak with the oak wilt fungus. The results are the vascular system clogging up causing leaves to turn tan, brown or bronze, and to fall rapidly from the tree.

The sap beetles lay their eggs in dead oaks and can often emerge contaminated with fungal spores (Johnson & Lyon 1987). The spore mat of the oak wilt fungus is commonly called a pressure pad. The pressure pad grows underneath the bark of an oak already infected with oak wilt from the previous year. This spore mat creates pressure on the bark and causes it to split. The beetles cannot resist the sweet smell of the fruiting body and will be drawn to it (Sinclair and others, 1987).

Not all methods of contracting the oak wilt disease are due to improper pruning. As described in scenario 2, branches break in strong winds or storms.

Not all oaks are extremely susceptible to oak wilt. Oaks in the red oak family (oaks with pointed lobes) are the most susceptible. Once infected with oak wilt, a mature, healthy red oak tree can die within the first month of contraction (Johnson & Lyon, 1987). Once a red oak contracts oak wilt, it is certain to die. Nothing can save a red oak tree after it is infected. Oaks in the white oak family (oaks with rounded lobes), however are much more resistant to the disease. The disease in white oaks is very slow to progress and white oaks can live with oak wilt for years (Johnson & Lyon, 1987).

It is very common to hear of heart breaking stories where a homeowner will try to save money by hiring a less-expensive, non-reputable tree company to prune their landscape trees. If an oak tree is to become infected due to improper pruning, all other oak trees on the property, as well as all oaks in the neighborhood, are at risk for contracting oak wilt.

We are approaching the autumn months, which is a good time to receive an estimate on getting your oaks pruned. After receiving an estimate, we will then schedule the tree work to occur in late fall or winter. If it is getting too late in the winter season and spring is near, we will wait until the following fall or winter before any tree work on oaks is done. We will not risk trimming your oaks too close to springtime.

Please email kimb@integritytree.com if you’re interested in receiving more information on oak wilt.

Gypsy Moths

An invasive species from Europe and Asia, the gypsy moth was introduced by a scientist living in Massachusetts in 1869, who was interested in breeding silkworms.  Not long after, some of the insects escaped and began to establish themselves (USDAFS 1989).  Millions of pure forests stands have been decimated by this little caterpillar.  Of course, as many homeowners may already know, they do not limit themselves to natural forest stands.  They are happy to enter our yards as well.

In the early spring, gypsy moth caterpillars hatch from their tan, oval-shaped egg sack.  Hundreds or up to a thousand tiny caterpillars crawl from each egg sack and make their way to greenery, often using silken threads so they may be dispersed by the wind.  As the caterpillars grow in size in the next several weeks, the amount of food they need to sustain themselves increases exponentially.  Seemingly overnight, whole areas of the canopy of a mature tree are defoliated.  That is when Integrity Tree Services receives phone calls.

Unfortunately many times with gypsy moth caterpillars, homeowners notice them only after the bulk of the damage is done. Colossal trees and forests can be put to waste in infested areas after thousands and thousands of caterpillars have their fill.  Beginning at just centimeters long, these caterpillars quickly grow to about 2 inches in a matter of weeks.  Once the caterpillars are identified, treating for them is not the tricky part, it is noticing the infestation before the majority of feeding damage occurs.
A female gypsy moth lays an egg sack in late summertime and dies soon after.  The egg sack remains over the winter and once the climate is right in the spring, the eggs hatch and the caterpillars emerge.  The caterpillars reach maturity after roughly 7 weeks in mid-summer, from there they pupate.  The pupation stage lasts for 1-2 weeks, and then a moth will emerge.  Once a moth, the brown male moths will fly around in search of flightless, white females (Johnson & Lyon, 1991).  It can be apparent where there has been an infestation of gypsy moth caterpillars during mid to late summer, for one will see dozens of brown gypsy moth males, fluttering all around.

Be sure to monitor your landscape in May of 2017, when the gypsy moth caterpillars grow large enough to be noticed.  Also keep an eye out for the egg sacks, which are usually laid in August.  If found and if within reach, destroying them with a stick is affective on a small scale. The gypsy moth caterpillars are easier to identify when they are larger, right before they pupate.  Look out for fuzzy caterpillars with blue and red spots. There are other caterpillars, which congregate in numbers, which could be mistaken for gypsy moth caterpillars, such as eastern tent caterpillars and fall webworms.

If you think you may have a gypsy moth caterpillar infestation starting, feel free to take a picture and email it to kimb@integritytree.com in order to receive confirmation of the infestation.  If you are unable to send a photo, feel free to call (616) 301-1300 extension 118 to schedule a free estimate with one of our certified arborists.

Most of the time, we can get our technicians to the scene same-day. Fortunately, there are some natural defenses present in the environment, which help control caterpillar populations. There is a soil-born fungus, which kills a large number of caterpillars, there is also a virus, and there are predators including, birds, parasitic wasps, flies and beetles (Johnson & Lyon 1991).

Be on the lookout for gypsy moth caterpillars next spring!  If you see them, call Integrity Tree Services right away!

What is Verticillium Wilt?

Verticillium wilt is a fungal disease that attacks many tree species. Common symptoms include wilting and browning leaves, falling leaves and quite commonly, a whole side of a tree or a single branch of a tree dying off. Checking the sapwood under the bark of the infected branches, brown streaks may be observed. These symptoms are caused by a soil-borne fungus Verticillium albo-atrum, which begins in the root system and travels through the vascular system of the tree. This causes blockage and prevents water and nutrients from reaching all of the branches. The tree responds to this infiltration by plugging the infected tissues and this increases the blockage of water and nutrients, thus causing leaf wilting and branch death. Symptoms commonly occur in the middle of summer when the climate is dry and hot.

There is no fungicide treatment for Verticillium wilt. Once a tree or shrub is infected with Verticillium wilt, it will eventually die. Resistant species should be planted in place of it after it is removed. Observe a tree if it begins to develops symptoms, as opposed to immediately removing it. Trimming out the dead branches as well as keeping the tree watered and fertilized may delay the infection. Once a tree is infected, however, there is no curing it. The fungus that causes Verticillium wilt can affect many tree species, however yews and conifers are not affected. What is more, the fungus can thrive in the soil for many years, therefore if a maple for instance dies of Verticillium wilt and if the maple is removed, another maple should not be planted in its place, for the fungus is still present in the soil. Common susceptible trees species are ash, boxwood, catalpa, cherry, elm, lilac, magnolia, 
maple, redbud, serviceberry and tulip trees. Common resistant trees are apple, beech, birch, ginkgo, hornbeam, linden, oak, pear, poplar, rhododendron, sweet gum and walnut. For a complete list of Verticillium wilt susceptible and resistant plants, please check online.

A tree can become more susceptible to Verticillium wilt if environmental conditions are poor, such as if the tree is experiencing drought, girdling roots, compaction, scorch or nutrient deficiency. Any stress on a tree can more readily allow infection to take root or can cause a tree to decline more quickly. Depending on the tree and conditions, a tree may die in a single growing season from Verticillium wilt or a tree may decline over the course of many years.

If you think Verticillium wilt is present in your landscape, please call (616) 301-1300 ext 118 to schedule an appointment with one of our certified arborists. To make sure a tree is suffering from Verticillium wilt, Integrity can take a plant sample and send it to the Michigan State University plant diagnostic lab in order to get it tested. The sample must come from the infected area of the tree, as the fungus is not usually throughout the whole tree. Several different branches about 1 inch diameter thick of live tissue should be taken to ensure accuracy. The test will cost $75 and will take 1-2 weeks for results to come back.

Helping Drought-Stressed Trees

The big concern arborists have is what the extent of reaction to the great heat and drought of 2012 will be. Efforts to mitigate, ease, and compensate this reaction will increase the survival rate and reduce the loss of roots and crown that would occur otherwise.

Pruning is helpful in this effort. In addition to increasing tree health through a carefully considered Crown Cleaning Pruning that a certified arborist can do. This same pruning can reduce the tree’s demand for energy, water, and nutrients. Branches that are diseased, infested, damaged, rubbing, etc, necessitates the tree to devote resources to them—detracting from the energy needed by the tree for basic life functions. This energy is even more limiting during drought conditions. Removing these kinds of branches has a lasting beneficial effect for years to come. Healthy branches make food (energy) for the tree and should not be removed during drought.

Heat and drought reduce fine root mass immediately. Branch death follows and will likely continue and could easily initiate a decline spiral. Decline spirals are notorious for continuing until the tree is dead, deformed, or rendered too compromised. Proper pruning along with watering can play a role to help interrupt this decline 
tendency and save a valuable shade tree from having to be removed or from losing health or stature.

All of the methods that help ease drought stress and damage should be employed and are listed here:
• Pruning to increase health and preserve energy (as described above).
• Applying mulch over the root system to conserve moisture and create an environment that promotes feeder 
 root replacement.
• Watering widely beneath the tree once per week, giving (at least) one inch per week will help the tree retain 
 roots and help the tree maintain its life functions.
• Spring Fertilization including root biostimulants will help restore lost vigor by supplying needed nutrients and 
 promoting feeder root replacement.
• Mycorrhizal root inoculations (beneficial symbiotic fungi) are especially useful for increasing drought 
 tolerance by increasing nutrient and water uptake.
• Compost Tea root zone injection will increase beneficial soil life to help restore the root rhizosphere and the soil 
 food web. This will also increase the performance of the root system and drought tolerance.

Certified Arborists are able to assess the conditions of each of your trees and help determine the best management plan. 
Take advantage of the knowledge, training, and experience our certified arborists have to help you and your landscape.

Simplifying the Emerald Ash Borer

Wouldn’t it be nice if all questions had simple answers? Life would be so much easier if all answers could be summed up in one word. Although there are no easy answers to 
the emerald ash borer. Hopefully we can help make your decision on what to do with your ash trees a bit easier.

Let us start with a couple of facts. We know that untreated ash trees are vulnerable to emerald ash borer (EAB). We also know that ash trees found to have EAB could still be saved if the borer population is low enough in those trees. Note: Trees with >40% crown thinning are heavily infested and no longer savable.

The confusion usually begins with the following questions: (1) When do I start treating my ash trees? (2) Do the treatments work? (3) How often will I have to treat my ash trees?

The answers to these questions may vary significantly depending on your circumstances. A search on Google, will reveal reports that are outdated along with some misinformation put out there by non-professionals. By the time you finish your research, you may end up having more questions than you started with.

Based on current university research, we will explain what our Tree & Shrub Care division is recommending to help protect your ash trees from EAB.

Where to start: Only treat the ash trees that you want to save. Determine which trees are the most important for your landscape and then have them assessed to determine if they are good candidates for treatment.

When to start: Once you have determined which ash trees you want to treat you should initiate a treatment plan as soon as possible.

What Treatments Work

Tree age insecticide: If any of your ash trees are within 15 miles of a known infestation and have not yet been treated or are already exhibiting signs of possible EAB activity, this is the product to start with. Tree age has thus far been proven to be the most effective product for helping save ash trees with light EAB activity. Note: There are no treatments to save heavily infested trees.

Imidacloprid: If your ash trees are farther than 15 miles from a known infestation, do not exhibit signs of EAB activity, or your ash trees have been getting soil injections of Imidacloprid already, then soil injections of Imidacloprid at the proper rate should be very effective at deterring EAB.

How Often to Apply

Tree age insecticide: The Tree age trunk injection is effective for two years at which time you can either continue with those treatments every other year or switch to the less invasive method of yearly soil injections containing Imidacloprid.

Imidacloprid: These soil injections, applied at the proper rate, need to be applied once annually.

So far, all of the research indicates that these options are currently the best for your ash trees in the given situations above. As you can see, there are many different factors that help determine what is best for your tree. The key to making any of these methods work for you is to have a professional come to your property to assess your ash trees.
Schedule an appointment today with one of our certified arborists. Call 616.301.1300!

Healthy Soils

Below the surface of the soil lies a complex soil food web we will likely never see. Without it, much of the plant life we enjoy would not be able to exist. The soil food web consists of many organisms that are beneficial to the health of the soil. This beneficial web is plentiful in an undisturbed forest setting, but can be diminished or lacking in some of the soils we have around our homes where our trees are trying to exist.

Many practices done to soils can disturb this fragile soil food web. Things like compacting the soil, over watering, lawn treatments, removal of leaves and small branches, etc… can have major impacts on this fragile web. A healthy soil will need organisms like nematodes, beneficial fungi, bacteria, protozoa, arthropods, and certain other animals in order to maintain a favorable growing environment. These organisms play a critical role in nutrient cycling. Nutrient cycling is the process whereby plant materials are broken down into usable nutrients for plants to carry on life.

The soil food web also creates beneficial soil structures for trees. Soils are much more 
complex than just a mixture of sand, silt, and clay. It is also made up of soil spaces and many other physical structures that allow root growth and expansion.

Girdling Root Syndrome

Fall 2012

 

 

 

 


Many times there can be problems below the soil where we can’t see.  Certainly this is usually the case with most root problems of the trees.  Girdling roots can be devastating to the tree if left untouched.  So what should you look for?

•    Reduced of slowed growth
•    Thinning or lack of leaves at the top of the tree
•    Deformation of the natural shape of the crown
•    Trunk splitting or cracking at ground level
•    Lack of or no visible root flare present where the trunk enters the ground (like a telephone pole)

Most of the time these issues start to appear just as the tree starts to become an important part of the landscape.  The reason for the delay is because it takes the roots some time to grow and cause these issues.  Any type of tree can be susceptible to girdling root syndrome.  The ones that we see most are Maples and Lindens.  Early detection is very important in helping the tree survive.  We have a tool that we use to do a root collar exam.  This tool is called an airspade.  An airspade is based on a compressed air system.  It is used to move the soil away from the tree without damaging the roots of the tree.  Once the soil is removed we are then able to selectively remove any roots that are girdling the tree.

Prevention is important.  Avoid the “volcano mulching.”  If the base of the tree has soil or mulch piled high around it, the roots will grow in that soil thus causing it to grow in a circling pattern.  Another good preventative measure is performing a root collar exam on any tree that has been in the landscape for 5-10 years.  This will check for soil buildup and will allow us to remove any circling roots before they become a problem.  So the next time you are looking over your landscaping, please ask yourself, “Do I see a good root flare?”  Or, does it look more like a telephone pole stuck in the ground?  If you think that you have a problem please call us right away.