Happy 2018 from P & A!

Happy New Year to all our past and present P & A Clients, and our business associates. We at P & A are excited at the prospect of working with you in 2018.

As we enter our 5th year (where did the time go?!) of business, we have several upcoming events to look ahead to.

In February, Peter will be attending the ISA Annual Conference in Huntsville. The ISA Annual Conference is always a fantastic opportunity to meet up with other Urban Forestry colleagues. In June, P & A hopes to participate again in the Aurora Street Festival. Connecting with the local community is always fun and it’s even better when the weather is nice!

Looking into 2018 with its frigid temperatures so far, it will be interesting to see how Gypsy Moth and Emerald Ash Borer populations may be affected.

2018 will be another educational year in urban forestry.

All the best in 2018 to you and yours!

Peter Wynnyczuk

Native Tree Selection Suggestions

Native Tree SelectionWhy select a native tree?

Native trees (not clones) help by providing birds, animals and insects habitat for their livelihood.

What species are considered native?

There are several that are listed on the Government of Ontario Website:

What research to do before buying native or any other trees?

When selecting native trees or other trees find out the ultimate height and width of the tree.

Other considerations are the Hardiness zone the plant can tolerate in terms of low or high temperatures for the area. Hardiness Zone Website:

Research if there are any known pests that could affect the health of the tree that requires more maintenance.

Determine what soils the tree prefers to see if it can tolerate your local conditions. Clay soils are tough for most trees.

How much space do you have?

Look up to see if there are any potential obstructions, i.e. communications/hydro wire.

How close do you intend to plant from structures?

Keeping in mind the ultimate size  of the tree will help you determine how far to plant from houses, garages, patios, houses and driveways.

Generally for a larger tree, such as Sugar Maple, as an example a minimum of 10m will ensure minimal maintenance for a large part of the trees life. For a smaller canopied tree such as Serviceberry, 4m is a good starting point.

For conifers or needled trees, generally having 6m from structures is suggested to minimize maintenance of interference.

If you are unsure of what to plant please call P & A Urban Forestry Consulting Ltd. to help you determine what is appropriate for the area you have for planting native trees!

Healthy Roots, Heritage Tree Program with the OUFC

On a beautiful Saturday morning in June, it was a pleasure to present information on the importance of our heritage trees that can affect our lives, on behalf of the Ontario Urban Forestry Council (OUFC). Heritage trees act as a reminder of how over decades and centuries they continue to provide many benefits to us and the natural environment.
The Ontario Heritage Act does provide some tools to help elevate the conversation on the importance of our cultural history through trees.
Ontario Urban forest Council and Forest Ontario do have a program to recognize historic trees in our neighbourhoods. Information at:

The morning was full of information presented by Sven Gleiser and Emma Thurston on a technique of growing nursery stock based on the Royal Botanic Garden Edinburgh system to minimize damage to roots and help prevent circling of roots as found in pots. The current practice of extracting a potted plant out of the container and slashing circling roots around the perimeter areas, causing untold damage and plant stress can be eliminated.

Edith George shared her wonderful story on the historic Red Oak in her neighbourhood and how it rated in terms of historic and cultural significance. A truly captivating presentation of how in all seasons this tree can have a majestic impact.

The afternoon was capped off with a tour of the area leading to the Necropolis cemetery, the Oldest one in the city dating from 1850, with its spectacular collection of trees and plants that have been cared for the the Mount Pleasant Group of Cemeteries over the last number of decades.
The colours of some of the plants flowers and scents presented was amazing. To see trees that surpass 125 years old that provide so many benefits to the casual walker or the local wild life was a pleasure to experience.

We look forward to future events of this kind to share in the local opportunities to talk about trees and the myriad of benefits they provide.

For more information and photos from the day, check out ocReLeaf!

On behalf of the Ontario Urban Forest Council,
Peter Wynnyczuk.

Gypsy Moth in Ontario

Gypsy moth is known as a forest defoliating insect. It is an invasive species that was brought over from Europe to North America in the 1800s, although it widespread defoliation did not occur until the 1980s in Ontario.

The gypsy moth is a threat to Ontario’s forests because of the damage it does to tree canopies. The moths lay eggs on tree bark in the winter and when they hatch, the caterpillars chew holes in leaves during the spring and early summer. Depending on the population, they can chew through an entire canopy. If caterpillars feed on a tree’s leaves for two seasons, the tree will likely die.

Identifying Gypsy Moth

The Gypsy Moth is found on a variety of tree species, such as oak, birch, beech, sugar maple, aspen, spruce, and pine.

The first sign of a Gypsy Moth infestation is the egg mass. Each spongy, beige coloured egg mass about the size of a loonie, can hold up about 600 to 700 eggs. These egg masses can be seen on the trunks and branches in late July until the following May when they start to hatch. The eggs hatch into hairy caterpillars about 50 mm long. They are darkly coloured, with a double row of five pairs of blue spots and six pairs of red spots down the back. After pupation, the moths are either light brown or white, depending on if they are male or female.

The caterpillars will chew holes through the leaves on a tree and are capable of defoliating an entire tree, even with regrowth during the summer.

In the early stages, Gypsy Moth infestations are particularly hard to diagnose, because feeding occurs primarily at night. It’s important for you to inspect your trees each spring and summer for egg masses, as well as monitor the health of the leaves on your tree for empty patches and holes.

What do I do if my tree is infested?

If you believe your tree is infested by the Gypsy Moth, you have a few options for maintaining your tree’s health.

First, if you notice egg masses on the bark, you can remove these by removing them gently with soap and water, vacuum with portable or hand held unit with extensions, or scrap them off with a putty knife depending on the bark condition. After collecting the egg masses in a container, you must either destroy them by burning or crushing them. Do not compost them as they will hatch and defoliate plants nearby.

To help monitor for Gypsy Moth caterpillars, you can place a band of burlap or cloth around the trunk of the tree. If present, caterpillars will hide under it in the heat of the day and you can easily find them and remove them. The caterpillars, while not poisonous, can cause irritation for some people. Always handle insects with gloves.

There are insecticides available to stop infestations. The small wasp and the fungus Entomophaga maimaiga are both biological controls of the Gypsy Moth.

If you suspect your tree is infested with Gypsy Moth, contact P & A. We can diagnose an infestation and make professional recommendations for treatment.

You should always report sightings of an Invasive Species. Report sightings to the toll-free Invading Species Hotline at 1-800-563-7711 or email info@invadingspecies.com.

Recently, the Government of Canada updated the regulated zones for Gypsy Moth. It’s important that you know these zones and follow the bylaws associated with them. Don’t move wood in or out of the regulated area to help prevent the spread of this invasive species.

Aurora Chamber Street Festival 2017

Last weekend we participated in the Aurora Chamber Street Festival for the second year in a row. We love coming here and hope it becomes a tradition for our business. It’s fantastic to meet other small business owners as well as people in the community.

It’s also always interesting to speak with festival goers about the issues they have with trees on their property. We hear about a variety of concerns, whether it’s people considering renovations, or people with sick or dying trees.

Since we began local festivals three years ago, the number of people who are concerned about Emerald Ash Borer is increasing. At this festival, we spoke to dozens of people who recently had their ash trees removed from their property. It’s a clear way to understand the impact that this species is having on local trees.

We’re so glad to have been a part of the Aurora Chamber Street Festival this year and hope to be part of it again next year!

Aurora Chamber Street Festival 2017 Aurora Chamber Street Festival 2017 Aurora Chamber Street Festival 2017 Aurora Chamber Street Festival 2017 Aurora Chamber Street Festival 2017 Aurora Chamber Street Festival 2017

What is a Certified Arborist?

An arborist is someone who is trained in the science of planting, planning, caring for, and maintaining trees. They are knowledgeable and equipped in regards to how to provide proper tree care in various environments.

What is a Certified Arborist?A Certified Arborist is a designation received by individuals who pass a comprehensive examination regarding various aspects of trees and arboriculture, including identification, diagnosing, and proper care methods and techniques. To maintain their certification, an individual must also adhere to the Code of Ethics, maintain membership and continue their education. This means they are up to date in their arboriculture knowledge and current events.

There are three streams of Arborists in Ontario in either a provincially recognized stream or industry recognized.

Provincial Recognition

  • Previously under the Ministry of Colleges, Training and Universities, MTCU, there was an apprenticeship program for both the trade of Arborist and Utility Arborist which was enacted in 1982. This program was moved, with the creation of the College of Trades. Members under the MTCU, if they did not join the College of Trades continue to hold their certificates.
  • Under the Ontario Ministry of Labour, through the College of Trades apprenticeship program the voluntary trades of Arborist and Utility Arborists require both workplace training and 24 weeks of “in school courses” related to working with and in trees. This hands on approach helps to provide for competent and safe tree workers.

College of Trades


The graduate of the apprenticeship program who;

  • Completed up to approximately 6, 000 hours of on the job training,
  • Completes the Training Standards Book,
  • Successfully completed the 24 week course and passes the written exam achieves a Certificate of Apprenticeship as appropriate in the Trade of Arborist or Utility Arborist.  Those who do not write the final exam receive a Certificate of Qualification in their respected trades

The College of Trades can discipline any members who are not meeting the requirements of the Trade. Apprentices in good standing are listed on the College of trades site: http://www.collegeoftrades.ca/public-register-search

Industry Recognition


  • Certified Arborists are designated and regulated by the International Society of Arboriculture (ISA). The examination is developed by industry experts on tree care. If a person is certified, they will be listed in the ISA database.
  • They have been exposed to the knowledge and time spent working in the field to reach certification.
  • They have up to date credentials and knowledge about tree care, health, and forestry

Because it is required to maintain certification, continuing education credits (CEUs) allow the Arborists to maintain their certification and stay current through taking courses, attending industry relevant presentations and other opportunities as they arise.

Trust your tree health and care to the professionals when you work with either group of Arborists!

Contact P & A to Work with a Certified ArboristCertified Arborist

P & A Urban Forestry’s president, Peter Wynnyczuk, is a Utility Arborist under the MTCU, #400113535 and a ISA Certified Arborist (ON-2067A). In addition to over 38 years of experience, he has the knowledge to work with and protect the health of trees on your property to keep them healthy.

We can take care of all your tree assessment, consulting, and reporting needs. Contact us today!


ISAO Annual Conference 2017

Last week, we attended the ISAO Annual Conference 2017 in Niagara Falls. It was a pleasure to attend an annual event with so many others in the urban forestry industry. This conference was a great opportunity to share knowledge and expertise about a variety of issues affecting our forests and trees in Ontario.

ISAO Annual Conference 2017There were several streams for each participant to engage in for their particular interest.  There was an emphasis on Tree Evaluation, Bylaws, and new tools (such as ground based radar) that are being developed to help determine root location. When developed further, these tools can help guide the decision makers about where structures can be placed to minimize root damage. It was also fantastic to hear about the efforts of the Women in Trees Committee and how it is progressing.

Of other keen interest is the 10th edition of the Plant Appraisal Guide that is currently out for comment for the practitioners to help finalize this tool used for tree valuation. There were also some suggestions for lesser known species of trees that could be used for the landscape or when replacing trees.

Lastly, it was great to see Fleming and Humber College Students on Thursday who participated in the conference and had a chance to learn with the other participants.

Looking back over thirty five years of participating in this event and many other events associated with trees, it was so nice to see so many familiar faces, so many new faces, and the next generation of help in tree care and urban forestry.

Common Types of Tree Fungus Affecting Ontario

One of the most obvious afflictions that affects trees is fungus. We see various types of tree fungus likely every day. Some types of tree fungus don’t harm the tree and actual provide benefits, while other types of fungus can damage the tree and lead to diseases and death.

Knowing the different types of fungus can help you understand when your trees are at risk.

Types of Tree Fungus

There are three main types of fungus that affect trees:

  • Symbiotic / Mycorrhizal fungi
  • Saprophytic fungi
  • Parasitic fungi

Symbiotic / Mycorrhizal fungi

Types of tree fungus

This type of fungus lives in association with many plants’ and trees’ root systems. Both the fungi and the tree benefit from the exchange. The fungi has access to the trees’ carbohydrate stores, and the tree grows its ability to absorb water and minerals because of the highly absorbent mycelium. Symbiotic fungi basically expands the root system of the tree on which it lives, allowing both the tree and fungus to grow stronger.

Common types of this fungus are Fly Agaric (Amanita muscaria) and Porcelain fungus (Oudemansiella mucida).

Saprophytic fungi

Saprophytic fungi are commonly seen on dead or dying plants and trees, although they are not often the cause of the death or decline themselves. It lives on dead organic matter and takes advantage of dieback caused by a separate factor, like drought or disease. Their role in the forest ecosystem is important, like symbiotic fungi, but they are not positive to see on trees. Seeing saprophytic fungi on trees often means the tree is already sick, dying, or dead and can contribute further to their mechanical failure.

Common types of saprophytic fungi are King Alfred’s Cakes (Daldinia concentrica) and Many-zoned Polypore (Coriolus versicolor).

Parasitic fungi

Parasitic fungi, as their name suggests, are the most damaging to trees and plants. They live off of their host tree and directly result in the death of the tree or plant. Usually, these fungi target trees that are already stressed or unhealthy, and can worsen conditions to kill the trees. In times of spreading infestations and infections, parasitic fungi can be particularly damaging to trees.

Dutch elm disease in the 1970s was caused by a parasitic fungus, microscopic Ophiostoma novo-ulmi. Honey fungus is another common parasitic fungus.

Common Diseases Caused by Fungus

When a fungus begins to live on a tree, it can make it susceptible to more diseases as it begins to weaken the mechanical structure of the tree. A spore can germinate under certain environmental conditions that produce hyphae (fungal tissue) that enter and feed on the host.

Some common examples of this are:

  • Root and butt rot disease – These diseases infect and kill the roots of the tree, causing decay and resulting in total tree failure with very little notice or visible symptoms
  • Canker diseases – These diseases enter through wounds on the tree and infect the bark tissue
  • Foliar / shoot diseases – These are the most common diseases caused by fungus. You can see blotches on leaves and needles that can lead to the death of the leaf and in some cases, the death of the tree
  • Vascular wilts – When wilts invade the tree’s vascular system, it interrupts the transport of water and nutrients

Management Options for Fungus on Trees

Unfortunately, fungus cannot usually be cured once it is living on a tree. There are not many tree fungus treatments available. Prevention is the best method for keeping your trees healthy without any negative effects from certain types of fungus.

Planting your trees in the right place, keeping them watered and fertilized in times of drought, and keeping them healthy can help prevent fungus from finding an opportunity to live on your tree. Correct pruning methods can help eliminate certain canker diseases and reduce the risk of open wounds on your trees. Fungicides do exist to control certain diseases caused by fungus and inhibit the growth of fungi, but these must be applied preventatively – before an infection occurs.

There are dozens of types of tree fungi that affect trees in Southern Ontario. An arborist can diagnose the types of fungus on a tree and let you know how it will affect the tree in the long term. Because there are so many types of fungi, there are many management options for the trees on your property.

If you suspect your tree is infected with a fungus, contact P & A. We can give a diagnosis and help create a management plan for preventing the spread of the fungus and keeping your trees healthy.

Asian Longhorned Beetle in Ontario

The Asian longhorned beetle is an invasive species that was introduced to North America in the 1990s and made its way to Ontario by 2002. It is originally from China and Korea where it is also considered a pest which kills a variety of native trees.

The Asian longhorned beetle typically targets broadleaf hardwood trees, including Birch, Maple, Elm, Hackberry, Horse Chestnut, Mountain Ash, Poplar, Sycamore and Willow. There is currently no treatment or insecticide prevention for the beetle, and a widespread infestation could lead to a problematic decline in our native hardwood trees and biodiversity. If a tree becomes infested, it will die.

The last sighting of the Asian longhorned beetle in Ontario was in Mississauga, near Pearson Airport in 2013. Asian longhorned beetle control has been strictly regulated, and with the proper guidelines and rules in place, this invasive species will hopefully be contained and not cause irreparable damage to our trees.

Asian Longhorned Beetle IdentificationAsian longhorned beetle in Ontario

The Asian longhorned beetle is can be easy to identify because of its unique appearance. Adults are 2-4 centimetres in length and can be identified by their shiny body with white, irregular spots and bluish-white legs. It has long antennae, typically twice its body length.

These characteristics make it a very noticeable insect when it is visible.

Damaged Caused

Asian longhorned beetle damage is easy to spot. Eggs will hatch in the summer and fall, allowing the larvae to tunnel into the tree trunk and limbs. The small tunnels made by the larvae weaken the tree and are what cause the damage that ultimately leads to the tree’s death.

Asian longhorned beetle identification can also be done by looking at the damage on the tree. In mid-summer and early fall, you will see weeping sap on the trunk of the tree and holes all around the bark of the tree. These holes will be about the size of a dime – typically, very noticeable.

Asian Longhorned Beetle Control

Currently, there are no treatments or insecticide prevention methods for this invasive species. Asian longhorned beetle control relies completely on identifying infested trees and preventing the spread of the infestation.

As the Asian longhorned beetle in Ontario was most recently found in the Mississauga area, there is a regulatory area of approximately 20 square kilometres (Finch, Martin Grove, Highway 401, and Dixie) where the movement of wood chips, bark chips, lumber, wood, trees, nursery stock, logs, and any other raw wood products is restricted. This regulation is necessary to prevent any potentially infested wood from spreading outside this area.

Because there are no treatments for an infestation, the tree will die if infested. It must be cut down and burned to prevent the spread of the insect further.

If you believe you see the insect or that your tree could be infested, call the Ontario Ministry of Natural Resources at 1-800-667-1940 or the Canadian Food Inspection Agency at 1-800-442-2342 to report it.
If you suspect your trees could be infested by the Asian Longhorned Beetle, contact P & A. We can help diagnose the infestation and inform you of the proper reporting methods to prevent the spread of the Asian longhorned beetle in Ontario.

Preventing Winter and Ice Storm Damage to Trees

Winter storms, particularly ice storms, have caused a lot of problems recently in Canada. A few years ago, we were hit with the polar vortex, causing massive power outages and damage. The ice storm in 1998 caused 6.2 billion dollars in damages, millions without power, injuries, and even deaths.

While the effect on humans is clear, ice storm damage to trees can also be severe and is often the cause of power outages and damage. Broken limbs and uprooted trees are common sights after a bad winter storm. Branch failure occurs when the loading from the weight of the ice exceeds the wood resistance, or when constant loading stresses a weakened area in the branch. Pair this with strong winds and branch failure is almost guaranteed.

Knowing the potential ice storm damage to trees, it is possible to prevent it. We can use the knowledge about the weaknesses and strengths of specific tree species to strategically plant and maintain trees with more resistance in our cities.

Ice storm damage to treesWhat Makes Trees Susceptible to Ice Storm Damage?

Apart from the power of the winter storm itself, there are a variety of factors that make a tree more susceptible to ice storm damage.

Weaknesses in the tree, present before a storm hits, make it less resistant to ice storm damage. Decay, dead branches, an increased surface area of lateral branches, restricted or unbalanced root systems, shallow root systems, weak branch junctures, and ingrown bark in branch junctures are just a few of the factors that weaken a tree before the storm even hits. Some of these factors occur naturally, such as species of oak trees having a naturally shallow root system, while some can be caused by human interaction, like a construction project damaging and weakening a tree’s root system.

Broad-leafed tree species with broad crowns are more susceptible to ice and snow damage. Species like Silver Maple, Weeping Willow, American Elm, Siberian Elm, Hackberry, Green Ash, White Birch and Honey Locust have broad crowns that are challenged when faced with excessive ice loads. On the other hand, trees with excurrent, or conical, branching patterns, strong branch attachments, and flexible branches are more resistant to ice storm damage to trees, as they are able to withstand higher weights and long storm durations.

Also important to consider is the positioning of trees. Edge trees, or trees that are located on the edge of a forest, are more at-risk than interior trees. They are less sheltered during a storm and bear the brunt of wind more so than interior trees.

Surprisingly, the source of the seeds used in tree planting is significant as well. A recent study found that seeds from trees from northern areas grew into trees that were more resistant to ice storm damage than seeds grown from trees from southern areas. Even when these seeds were grown in the exact same conditions, they had very different levels of resistance to winter weather.

Urban Forestry Management for Ice Storm Damage to Trees

There are many things that urban forestry management can do to prevent ice storm damage to trees and the consequential damage to buildings, roads, and infrastructure.

  • Have your trees assessed for any defects or structural issues and make appropriate decision(s)
  • Plant trees where they can do the least damage, away from power lines or large buildings, for example
  • Remove diseased or injured trees or ensure regular pruning to remove damaged areas
  • Remove damaged trees immediately after storms
  • Plant tree species that are more resistant to storms
  • Plant trees using seeds from northern seed-sourced trees

Species and Practical Examples

Knowing tree species that can resist ice and snow damage from severe winter storms is the first step in incorporating them into an urban forestry management plan and ensuring our trees and infrastructure is safe in future winter storms.

Different characteristics of tree species can make them either good or poor choices for planting in areas that receive heavy snow and ice. Jack pines and sugar maples have a higher chance of dying if they have severe canopy damage, but pitch pine and American beech species have a much better sprouting ability and can recover from severe branch loss. Bradford pear tree branches have ingrown bark in branch junctures, weakening them against heavy snow, while the Aristocrat cultivar of the pear species has stronger branch junctures and can withstand more weight.

Some other examples of trees resistant to ice storm damage to trees are Balsam fir, bur oak, Eastern hemlock, mountain ash, Ohio buckeye, and the Norway maple (some consider this an invasive species). More susceptible trees include the Silver maple, Siberian elm, American elm, black ash, butternut, common hackberry, red elm, and willow.

Knowing the tree species and various characteristics that affect how a tree can withstand ice, snow, and storm damage prepares us to create an urban forestry plan that will foster the growth of more resistant trees. This will help eliminate damage to infrastructure and property by trees after future storms.

To read the entire report and view a list of resistance vs susceptible tree species, visit the recent publication by the University of Nevada Lincoln, Trees and Ice Storms: The Development of Ice Storm–Resistant Urban Tree Populations (Second Edition).

If you’re concerned about ice storm damage to trees on your property this winter, contact P & A. We can assess storm damage and help you prepare your trees for upcoming storms.