Resources
When are permits required to remove a tree within the City of Ottawa?
When are permits required to remove a tree within the City of Ottawa?
If you’re planning to cut down and remove a tree on your Ottawa property, you may need to obtain a tree removal permit from the City of Ottawa. The general guideline is based on the tree’s size: any tree with a diameter greater than 30 centimetres (approximately 12 inches), measured at the chest height, typically requires a permit for removal.
However, there are several exceptions where a permit is not needed:
- The tree is under 30cm in diameter and the property is smaller than one hectare
- It’s located within an interior courtyard, solarium, rooftop garden, or similar enclosed space
- The tree poses an immediate risk to health, safety, or infrastructure and must be removed urgently
- The tree is situated on agricultural land, a nursery, a cemetery, or a golf course
- You are only pruning the tree (e.g., cutting branches or trimming sections), not removing it entirely
Removing a tree in Ottawa without the required permit can result in serious penalties. Violations of the city’s tree protection bylaws can lead to fines ranging from $500 up to $100,000.
How to obtain a tree permit
Whether a tree is located on public or private property in Ottawa, a permit must be obtained before it can be removed, as required by city by-laws.
If the tree removal is not related to infill development, the permit application fee is $186 per tree, up to a maximum of five trees. For removals connected to infill development, the fee increases to $1055 per tree, up to a maximum of five trees.
Permit applications can be submitted online, but you must also complete and submit a Tree Information Report as part of the process. This report must be completed by a certified arborist.
Once your application is approved and the permit is issued, Ottawa by-law mandates that the permit be visibly posted on the property for at least 7 days before and 7 days after the tree is removed. In addition, the notice must also be clearly displayed on the tree itself for 7 days prior to removal.
Planning to remove a tree with a trunk diameter of 30 cm or more? In that case, you’ll need to apply for a Distinctive Tree Permit from the City of Ottawa. If the tree’s trunk crosses onto a neighbour’s property, their consent will also be required before any removal can take place.
To make sure you’re fully compliant with Ottawa’s tree removal bylaws, it’s wise to consult a certified arborist. At Green Thumb Tree Specialists, we are here to guide you through the permit process and ensure your tree removal is handled safely and legally. Reach out to us today to learn how we can assist.
Why are permits required?
Ottawa’s tree removal permit system was created to help preserve the city’s urban forest and maintain a healthy balance of green space. Trees not only produce oxygen and improve air quality, but they also enhance the beauty of neighbourhoods—something that becomes increasingly important as construction and development expand across the city. While a tree may be located on your private property, its presence contributes to the overall well-being and visual appeal of the entire community, benefiting your neighbours and the city as a whole.
Why hire a certified arborist?
Investing in proper tree care benefits both your property and your quality of life. While basic yard work like lawn mowing or trimming shrubs can be a DIY task, larger trees require the expertise of a professional.
Certified Arborists are trained specialists in the science and care of trees. They not only help nurture healthy growth across your property but also handle specific tasks like pruning and removal with precision and safety. When it comes to larger or potentially hazardous work, it’s always best to rely on a certified expert.
Hiring a Certified Arborist offers several advantages:
- Enhances tree health
- Encourages strong, healthy growth
- Improves overall appearance
- Increases sunlight exposure
- Eliminates safety hazards
Whether you’re managing a small backyard or a large commercial landscape, professional tree care helps maintain a safer, more attractive property. Well-maintained trees can boost curb appeal and increase property value. Choosing a certified arborist sends a clear message—to your family, neighbours, clients, and potential buyers—that you take pride in your property and care about those who visit it.
What is Ottawa’s tree protection bylaw?
As of January 1, 2021, Ottawa’s updated Tree Protection By-law is in effect. This new regulation replaces the former Urban Tree Conservation By-law and the Municipal Trees and Natural Areas Protection By-law, combining them into a single, streamlined policy. The revised by-law introduces changes to how tree protection is enforced, including updated permit requirements and removal guidelines. If you’re considering tree removal, it’s important to understand how these changes may affect your plans. Read on to learn what you need to know.
The Tree Protection By-law in Ottawa applies differently depending on where the tree is located within the city. The regulations are divided into three distinct zones: Urban, Suburban, and Rural. Urban areas include Ottawa, Nepean, and Vanier, while suburban areas cover communities such as Kanata, Orléans, Barrhaven, Stittsville, Greely, and Manotick. All other parts of the Greater Ottawa Area are classified as rural. Each zone has specific guidelines and requirements when it comes to tree protection and removal, so it’s important to know which area your property falls under before proceeding with any tree-related work.
When applying for a tree removal permit in Ottawa, you’ll need to submit an arborist report as part of the application. In most cases, this will be a Tree Information Report (TIR). However, if the tree is located on a property larger than one hectare or the site is part of a Planning Act application, a more comprehensive Tree Conservation Report (TCR) is required. The level of detail in the arborist report depends on the reason for removal, which falls into three main categories. No Development removals—such as those due to tree condition or minor construction projects like decks, pools, or walkways—typically require a TIR Short report. Infill Development, involving new low-rise residential builds that aren’t subject to the Planning Act, will require a TIR Full report submitted during early application stages, such as the Committee of Adjustment or permit phase. For properties over one hectare or those tied to a Planning Act process, a Tree Conservation Report is necessary, following the same standards outlined in the former Urban Tree Conservation By-law. Every report must include contact information for the property owner, the arborist preparing the report, and—if available—the contractor responsible for removing the tree.
A Short Tree Information Report typically includes key details such as the tree species and its diameter at breast height (DBH), tree ownership, an assessment of the tree’s condition, its exact location, the reason for removal, and the arborist’s recommendation. It may also include additional supporting documents if needed, along with a photo of the tree. A Full Tree Information Report contains all the elements of a short report, plus more comprehensive documentation. This includes proposed tree protection and mitigation measures, confirmation of boundary trees (including those on neighbouring properties with critical root zones extending into the work area), and detailed site or grading plans. These plans must clearly indicate which trees are being removed, which are being retained, the location of critical root zones, and the placement of any replacement trees.
Recent updates to Ottawa’s tree removal regulations have introduced several changes to both the permitting process and public notification requirements. What was previously called a “Distinctive Tree Permit” is now referred to as a “Tree Removal Permit.” The criteria for tree protection have also been revised: previously, only trees with a diameter of 50 cm or more in urban areas were protected. Now, protection extends to trees 30 cm or more in diameter in urban areas, 50 cm or more in suburban areas, and all city-owned trees, regardless of size. Additionally, while a single permit once covered multiple trees on the same property, a separate permit is now required for each individual tree slated for removal. As part of the new rules, a public notice must also be posted directly on each tree at least 7 days before removal to ensure transparency and community awareness.
COMMON TREE DISEASES AND PESTS IN THE OTTAWA AREA:
Anthracnose:
Countless property owners have to schedule tree removal and other tree services in Ottawa to combat pest infestations and tree diseases. Your vegetation may be susceptible to certain wood-boring insects that chew through trees and weaken their structural integrity.
Tree diseases remain a threat and require immediate intervention to save a decaying tree. Keep an eye out for changes in your tree’s appearance and reach out to our arborists for assistance. We can diagnose common pest infestations and tree diseases that may be impacting your vegetation.
Symptoms
Symptoms vary widely, from small, circular or irregular spots in shades of tan, dark brown, or black, to larger blotches on the leaves. Young, infected leaves may become distorted due to abnormal growth and often die and drop soon after heavy infection.
Causes
- Prolonged wet or damp weather conditions
- Poor air circulation within dense or thick foliage
Treatment & Prevention
- Regularly clean up and destroy fallen leaves to reduce the presence of anthracnose spores.
- Hire a professional arborist to prune your tree properly, improving air flow and light penetration within the canopy.
- Keep your tree healthy with appropriate watering (applied at the dripline rather than on leaves) and follow a consistent fertilization program.
Fertilizing Method
Fertilization is typically done through hydraulic injection around the tree’s dripline, approximately 12 to 16 inches below ground. A slow-release NPK fertilizer (with a ratio of 30-8-8 for nitrogen, phosphorus, and potassium) is used. This minimally invasive treatment should be repeated every other spring until the tree fully recovers, a process that may take several years. Stopping fertilization prematurely can harm the tree’s health and allow the problem to persist or worsen.
Note: In some cases, persistent environmental factors may prevent anthracnose from completely disappearing from a tree.
Apple Scab:
Symptoms
In spring, crab apple leaves often develop dull olive-green spots with a velvety texture on both sides. These spots are generally circular with fringed edges and can vary in size from tiny pinpoints up to half an inch or more in diameter. Secondary infections cause irregularly shaped spots along the leaf veins. Under warm (around 75°F) and humid conditions, a “sheet scab” can form, where the entire leaf surface appears covered in a gray-green, moldy layer. While symptoms may vary slightly among different crab apple varieties, scab is usually easy to spot once familiar. When conditions favor disease development, infected leaves turn yellow and fall early, leading to premature defoliation. Crab apple fruit can also become infected when spores from leaves land on the fruit, resulting in small, dark, raised scabby lesions. When these spots are numerous, the fruit can become cracked, misshapen, and drop prematurely.
Disease Cycle & Control
The scab fungus survives winter in fallen infected leaves and fruit. During wet spring weather, typically around the time buds break, spores are produced in reproductive structures on this debris. These spores are forcibly released and infect young, wet leaves. Leaf spots appear 8 to 18 days later, depending on temperature. Throughout the growing season, secondary infections continue whenever conditions are favorable, often causing severe defoliation. Repeated defoliation weakens crab apple trees and may reduce flowering the following year.
Management
A key preventative step is to rake up and destroy or compost fallen leaves and fruit, removing the fungus’s overwintering sites. Additionally, having your trees fertilized by professional arborists helps boost their health and vigor to better resist infection.
Fertilizing Method
Fertilization is done using hydraulic injection around the tree’s dripline, about 14 to 16 inches below the soil surface, with a slow-release granular fertilizer containing Nitrogen, Phosphorus, and Potassium (NPK ratio 14-6-12). This non-invasive treatment should be repeated each spring until the tree has fully recovered, which may take several years. Stopping fertilization prematurely can negatively impact the tree’s health and recovery.
We don’t just show up and chop down your tree. We assess every case on an individual basis and communicate and listen to our clients to ensure their needs and concerns are met.
Cytopsora canker:
If you notice the lower branches of your spruce tree starting to die back, Cytospora canker is likely the cause. While other diseases like needlecast can also affect spruce, Cytospora is the most common culprit. This fungal disease spreads through airborne and waterborne spores. Once the fungus enters the branch’s cambium layer, it creates a canker—an infected area—that produces a distinctive white resin or gummy sap. This sticky ooze is the tree’s natural response to injury and serves as a helpful diagnostic sign. As the canker grows, it eventually encircles the branch, cutting off nutrients and killing it. Typically, the infection begins on the older, lower branches, although this is not always the case. Needles on affected branches often first turn purple before browning and dying.
If the canker develops on the main trunk, it disrupts the flow of water and nutrients, causing the branches above the infected area to die off. Cytospora canker can affect trees of all ages but is most
common in those over 15 years old. The disease usually develops when the tree is stressed or wounded. Common urban stress factors include drought, excessive watering, winter damage, insect attacks, mechanical injuries (like from lawnmowers), and construction activities. Among these, drought stress is often the most significant trigger for Cytospora canker. Since there is no cure, prevention is critical. The best defense is maintaining your spruce’s overall health and vigor.
To keep your tree healthy and reduce the risk of Cytospora, follow these important care steps:
- Create a mulch bed around the tree’s base to retain soil moisture and protect the trunk from damage.
- Water the tree during dry spells as needed, but always check under the mulch first to avoid overwatering, which can harm roots and weaken the tree. Using a soaker hose at the tree’s base is preferable to sprinklers, as wetting foliage may promote disease spread.
- Prune out infected branches promptly, disinfecting pruning tools between cuts to prevent spreading the fungus.
- Fertilize the tree every two years using a slow-release, injected fertilizer formula to maintain its strength and vitality.
By following these simple steps, you can help your spruce stay healthy and better resist Cytospora canker.
Rhizosphaera (Needle Cast of Spruce):
This fungal disease typically begins by affecting the lower parts of the tree and gradually spreads upward. Infected needles first turn a purplish-brown shade and eventually fall off prematurely. Although the infection occurs in the spring, visible symptoms usually don’t appear until the following spring—about a year later. At that point, tiny black specks become noticeable on the upper surfaces of the needles. These specks, visible with a hand lens, are fungal spores emerging from the needles’ natural openings called stomata. These spores then go on to infect additional needles on the tree.
Usually, infected needles turn purplish-brown before dropping off during late summer of their second growing season. The disease often starts on the lowest branches and slowly moves upward. On branches with severe infection, only the current year’s needles remain, as second-year needles fall off early in the summer. While heavy infections can kill a tree, most often the disease simply causes thinning in the tree’s center and death of some lower branches, especially after several consecutive years of early needle loss.
For minor infections in established trees, applying Bordeaux mix fungicide twice—once in early June and again in early July—can control the disease. Usually, two consecutive years of treatment will help restore moderately affected trees to full, healthy foliage. Another important prevention tip is to avoid watering the tree’s branches directly, as moisture on the needles encourages disease spread.
*Note: Severely infected trees may not respond to fungicide treatments and could require complete removal.
Thyronectria Canker (Honey Locust):
In most cases, the key to a tree’s longevity lies in maintaining its overall health. Proper soil aeration, consistent watering, and regular feeding are essential to help your tree thrive and provide all the benefits you expect from it. When it comes to Thyronectria Canker in Honey Locust trees, drought stress is often the primary trigger for the disease. This fungal infection enters the tree through wounds, much like many other diseases.
Unfortunately, there is no quick cure or magical spray to eliminate this fungus. The best approach is to identify and manage the stress factors affecting the tree. Promoting strong tree health remains the most effective defense against this disease. Because drought stress worsens the condition, many tree owners don’t realize that trees need ongoing care, including adequate watering and attention, to stay healthy.
The disease manifests as sunken, discolored patches of bark that can affect both new and mature growth on branches and trunks. As the infection spreads, affected branches begin to die back from their tips, causing the tree to look weak and declining. On older wood, such as the trunk or larger branches, the fungus spreads through lenticels (small pores in the bark) or enters via wounds caused by lawn equipment or landscaping activities.
The cankers usually appear as elongated, sunken lesions with callus ridges along the edges. The bark in these areas turns from orange-brown to a yellow-orange color over time. Symptoms include annual and perennial cankers of varying sizes on trunks and branches. These cankers can girdle the tree or branches, leading to yellowing or wilting foliage, followed by dieback. After the bark dies, fungal tissue grows out of the canker and produces spores that spread the disease further.
To help trees resist this pathogen, it’s important to maximize their vigor through regular watering during hot, dry periods and a balanced fertilization program. While removing infected wood and branches can improve the tree’s appearance, it doesn’t cure the disease. Unfortunately, many Honey Locust trees eventually succumb to this condition despite these efforts.
Sun scald:
Sunscald in trees appears as damaged or discolored bark, typically on the south or southwest side of the trunk and lower branches. During winter or early spring, intense sunlight heats the bark during the day, causing the cells to become active, followed by rapid cooling at night that damages or kills the bark tissue. This damage often results in sunken, cracked, or peeling bark, and can expose the inner wood, making the tree vulnerable to pests and diseases. Sunscald is caused primarily by fluctuations in temperature and sunlight exposure, especially on young or thin-barked trees that lack natural protection. To treat and prevent sunscald, it’s important to protect susceptible trees by wrapping the trunk with tree guards or protective wraps during winter months, applying mulch to maintain consistent soil moisture, and ensuring the tree is healthy through proper watering and fertilization. Promptly removing damaged bark and monitoring for secondary infections can also help the tree recover and prevent further harm.
Black knot:
Black knot is a common fungal disease affecting primarily cherry and plum trees in Eastern Ontario. It is caused by the fungus Apiosporina morbosa, which infects trees through wounds or natural openings in the spring. The disease is characterized by rough, black, swollen galls or knots that develop on branches and twigs. These knots start small and olive-green in color but gradually enlarge, harden, and turn jet black over time. As the disease progresses, the knots can girdle branches, causing dieback and weakening the tree.
To treat black knot, the best approach is early and consistent pruning. In late winter or early spring, before buds break, prune out infected branches at least 10-15 cm below visible knots to ensure removal of the fungus. Properly dispose of the pruned material by burning or removing it from the property to prevent spores from spreading. Fungicide treatments can be helpful as a preventive measure in early spring but are less effective once knots have developed.
Prevention focuses on maintaining tree health and hygiene. Plant resistant varieties if possible, avoid wounding trees during pruning or landscaping, and prune regularly to improve air circulation and sunlight penetration, which helps reduce fungal growth. Monitoring trees each year and removing new infections promptly is critical to managing black knot and protecting your cherry and plum trees from serious damage.
Oak Wilt:
Oak Wilt is a serious fungal disease that affects oak trees, particularly in North America, and it has been increasingly recognized in parts of Ontario, including Eastern Ontario. It’s caused by the Bretziella fagacearum fungus, which invades the vascular system of oaks and disrupts water and nutrient flow. The disease is highly contagious and can spread quickly from tree to tree, especially in areas with dense oak populations.
How Oak Wilt Presents:
Symptoms in Trees:
- Early Signs: Oak wilt usually begins with wilting of the upper branches of infected trees, particularly in the canopy. The leaves start to turn yellow and then develop a reddish-brown discoloration at the edges (leaf marginal necrosis).
- Rapid Dieback: As the disease progresses, the affected leaves may curl, dry out, and fall prematurely, especially in the upper portion of the tree. In severe cases, entire branches or even whole trees may die within weeks or months.
- Red and White Oaks: The disease behaves differently in different oak species:
- Fungal Mats: In late summer, fungal mats (or spore pads) may form under the bark at the base of the tree. These mats release spores that are spread by beetles, primarily sap-feeding beetles.
Spread of Oak Wilt:
- Root Grafting: The disease can spread through interconnected roots when oak trees are growing in close proximity. If one tree is infected, it can pass the fungus through shared roots to nearby trees.
- Beetles: Sap-feeding beetles (e.g., picnic beetles) that feed on freshly cut or wounded trees can carry fungal spores to healthy trees, further spreading the disease.
How to Treat Oak Wilt:
- Remove Infected Trees: If oak wilt is detected, remove and destroy infected trees as soon as possible. This will help stop the disease from spreading. Ensure that the tree is completely destroyed (burning or chipping is advised).
- Pruning: Any pruning of oak trees should be done during the winter months (from November to February) when beetles are not active. If pruning occurs during the growing season, the tree should be sealed immediately to prevent beetle access to the tree.
- Fungicide Treatments: In some cases, fungicides may be used to protect healthy trees near infected ones. However, they are generally more effective as a preventive measure and not once the tree has already shown symptoms. Your arborist can inject fungicide into the tree to help protect it from the fungus.
- Root Grafting Disruption: If oak trees are close together, an arborist can trench between them to sever root connections and prevent the disease from spreading via the root system.
How to Prevent Oak Wilt:
- Avoid Wounding Trees: Oak wilt is spread by wounds, so avoid cutting, pruning, or injuring oak trees during the growing season (April to October). If you must prune, always do so during the dormant season (fall to early spring), and use a tree wound sealant to close any cuts.
- Fungicide Application: For trees at high risk (e.g., if they’re near infected trees or in an area with high oak wilt prevalence), fungicides can be applied as a preventive measure. Arborists can inject trees with fungicides to help protect them from infection.
- Quarantine Infected Areas: If oak wilt is present in your area, avoid transporting firewood, logs, or branches from infected trees to other areas. This helps to stop the spread of the disease to other regions or neighborhoods.
- Remove Infected Trees Promptly: As mentioned earlier, removing infected trees quickly is crucial to prevent the disease from spreading to healthy trees. This is particularly important if your trees are within close proximity to each other.
Conclusion:
Oak wilt is a dangerous and fast-moving disease that can devastate oak trees, especially in areas with a high concentration of oaks. Preventive measures, such as avoiding injury to trees, timely pruning, and managing root systems, are essential to keep trees healthy and reduce the risk of infection. If oak wilt is suspected, it’s essential to work with a certified arborist to ensure proper diagnosis and treatment of the disease.
Dutch Elm Disease:
Dutch Elm Disease (DED) is a serious and often fatal fungal disease that affects elm trees, especially the American Elm (Ulmus americana) and European Elm (Ulmus glabra). The disease is caused by the fungus Ophiostoma ulmi (and its variant Ophiostoma novo-ulmi) and is transmitted primarily by elm bark beetles. In Eastern Ontario and much of Canada, Dutch Elm Disease has devastated native elm populations, particularly in urban and suburban areas.
How Dutch Elm Disease Presents:
Initial Symptoms:
- Wilting and Yellowing of Leaves: The disease first manifests as wilting and yellowing of the leaves on one or several branches, typically starting at the top of the tree. The leaves may then turn brown and curl as they dry out.
- Uneven Symptoms: Unlike some other tree diseases, DED often affects branches unevenly, so not all parts of the tree will show symptoms at once. Initially, it’s common to see wilting on only one side or a portion of the tree.
- Browning of Vascular Tissue: If you cut into an infected branch, you may notice dark streaks in the wood, particularly under the bark. This discoloration is caused by the fungus blocking the vascular tissues (xylem), preventing the tree from getting water and nutrients.
- Defoliation: As the disease progresses, the affected branches lose their leaves early, leading to premature defoliation in late summer. The tree may become more and more sparse in appearance.
Advanced Symptoms:
- Rapid Decline: If the disease is not addressed, it can rapidly progress to the death of large sections or the entire tree. Over a few months to a year, the tree can die as the fungus completely blocks water and nutrient flow through the vascular system.
- Dieback: The fungus often moves quickly from the branches into the main trunk. In advanced cases, the entire tree can die as the vascular system is compromised, leading to rapid dieback.
- Bark and Beetle Activity: In some cases, you may also see small holes in the bark where elm bark beetles have been feeding. These beetles carry the fungus from one tree to another.
How Dutch Elm Disease Spreads:
- Elm Bark Beetles: The primary method of transmission is through beetles, particularly the Hylurgopinus rufipes and Scolytus species. These beetles become infected when they feed on the sap of an infected tree. As they move from tree to tree, they spread the fungal spores into healthy trees, where they enter through the bark.
- Root Grafting: While beetles are the main vector, the disease can also spread between nearby trees through grafted roots, particularly in areas with dense elm populations.
How to Treat Dutch Elm Disease:
Removal of Infected Trees:
- Immediate Removal: If Dutch Elm Disease is suspected, it is critical to remove the infected tree as soon as possible. The tree should be cut down, and all infected material (branches, logs, etc.) should be destroyed. Burning the wood or chipping it into small pieces can help prevent the spread of the disease.
- Disinfecting Tools: When pruning or removing infected wood, disinfect your tools between cuts to prevent spreading the fungus to healthy trees.
Fungicide Treatments:
- Fungicide Injection: If the infection is detected early, a systemic fungicide can be injected into the tree to help protect healthy parts of the tree and slow the spread of the disease. Fungicides can be effective when used preventively or in the early stages of the disease.
- Fungicide Spraying: In urban settings with known outbreaks, some municipalities use fungicides on a preventive basis, especially for high-value trees in public spaces.
Elm Bark Beetle Control:
- Insecticide Treatment: To reduce the spread of Dutch Elm Disease, controlling the beetles is essential. Insecticides can be applied to trees to kill beetles or reduce beetle populations.
- Trap Trees: You can use trap trees by pruning the infected branches in late spring and early summer. These “trap trees” can be cut down and destroyed once beetles are attracted to the infected wood.
Pruning
- Prune Properly: Prune infected branches early and always in the winter to avoid attracting beetles. Disinfect pruning tools between cuts to prevent cross-contamination.
How to Prevent Dutch Elm Disease:
Preventive Fungicide Treatments:
- Fungicide Injections: In high-risk areas, preventive fungicide injections can be applied every two to three years to protect healthy elms from the disease. These injections are typically done by professionals and may be most useful for mature or valuable trees.
Control of Elm Bark Beetles:
- Insecticide Application: If there is a known issue with elm bark beetles in your area, using insecticides during beetle season (spring and early summer) can help reduce the beetle population. Be sure to apply insecticides to affected trees and surrounding healthy trees to reduce the chances of spreading the disease.
- Sanitation: Prune and remove any dead or dying wood from your trees in late winter or early spring to avoid attracting beetles. Make sure that infected tree material is disposed of properly to prevent beetles from using it as a breeding ground.
Tree Health Maintenance:
- Proper Tree Care: Maintaining overall tree health by watering, mulching, and fertilizing trees can help them resist disease and recover from potential infections. Trees that are stressed (due to drought, mechanical injury, or other factors) are more vulnerable to Dutch Elm Disease.
- Limit Pruning During Peak Beetle Season: Prune elm trees during the winter when beetles are inactive, and never during spring and summer when beetles are active.
Pruning
- Prune Properly: Prune infected branches early and always in the winter to avoid attracting beetles. Disinfect pruning tools between cuts to prevent cross-contamination.
Monitoring and Early Detection:
- Regular Inspections: Regularly inspect your elm trees for early signs of Dutch Elm Disease, particularly wilting, yellowing leaves, or any bark discoloration. Early detection is crucial for preventing the spread of the disease.
- Professional Help: If you suspect an infection or if you’re unsure of what to look for, contact a certified arborist to inspect your trees. Professionals can help diagnose the disease, apply treatment, and recommend strategies for keeping your trees healthy.
Conclusion:
Dutch Elm Disease is a deadly fungal infection that can wipe out entire populations of elm trees if left untreated. Prevention, early detection, and proper treatment are essential to managing the disease. By controlling elm bark beetles, maintaining tree health, and using fungicide treatments, you can protect your elms from this devastating disease. If you spot symptoms of DED, it’s crucial to act quickly to remove infected trees, prevent the spread, and protect your remaining elms.
Pine Blight:
Pine Blight is a term used to describe a group of diseases that affect pine trees, with the most common being White Pine Blister Rust, Dothistroma Needle Blight, and Sirococcus Shoot Blight. These diseases can have serious consequences for pine trees, especially in regions like Eastern Ontario where pines are abundant. Here’s a breakdown of how pine blight diseases present, how to treat them, and how to prevent them.
1. White Pine Blister Rust (Cronartium ribicola)
How It Presents:
- Symptoms on Needles: Initially, white pine blister rust affects the needles of white pines, turning them yellow or orange. These discolored areas develop into brown, necrotic patches as the disease progresses.
- Cankers on Branches: The disease forms cankers, which are swollen, sunken areas on the bark, typically around the branch junctions or on the trunk. These cankers are caused by the fungus growing under the bark and blocking the tree’s vascular system.
- Orange Spore-producing Structures: In the later stages, small, bright orange, blister-like structures appear on the cankers during the summer, indicating the presence of the fungal spores.
- Needle Drop and Dieback: Infected trees often exhibit premature needle drop, and eventually, branches die back. As the disease spreads, it weakens the tree and can lead to overall tree decline or death.
Treatment:
- Remove Infected Branches: If caught early, pruning infected branches and properly disposing of them can slow the disease’s progression.
- Fungicide Application: Fungicides may help control the spread of white pine blister rust, particularly if applied to the tree before the disease becomes too severe. Fungicide treatments are often applied during spore release periods in late spring or early summer.
- Infected Tree Removal: In severe cases, especially in commercial or high-value landscapes, removing infected trees may be necessary to prevent the spread of the disease.
Prevention:
- Plant Resistant Varieties: Some varieties of pine are more resistant to white pine blister rust, so planting these varieties can reduce the risk of infection.
- Control Alternate Hosts (Ribes): The disease needs Ribes (currant and gooseberry bushes) to complete its life cycle. Removing these plants around pines can help break the cycle of infection.
- Regular Monitoring: Periodically inspect your pine trees for signs of white pine blister rust. Early detection is crucial for minimizing damage.
Dothistroma Needle Blight (Dothistroma septosporum)
How It Presents:
- Yellowing and Browning of Needles: One of the first signs of Dothistroma Needle Blight is the appearance of yellow or orange bands across the needles, usually near the tip. The tips of the infected needles turn brown, and the discoloration spreads down the length of the needles.
- Needle Drop: As the disease progresses, infected needles often fall prematurely, leaving the tree with sparse foliage. In severe cases, the entire crown of the tree may become bare.
- Tree Decline: Over time, repeated infections lead to thinning of the crown, stunted growth, and overall tree decline.
Treatment:
- Pruning Infected Needles: Remove infected needles during dry weather to reduce the spread of the disease. Pruning helps reduce the fungal load and improves tree health.
- Fungicide Applications: Fungicides can be used to control the spread of Dothistroma Needle Blight. It is most effective when applied in early spring before new growth begins or just before needle infection occurs.
- Tree Health Maintenance: Improve tree vigor by providing proper water, nutrients, and mulching to help the tree recover and resist future infections.
Prevention:
- Proper Spacing and Air Circulation: Ensure that pine trees are planted with sufficient spacing to improve air circulation around the trees. Crowded conditions contribute to increased humidity, which favors the spread of the disease.
- Avoid Overhead Watering: Avoid wetting the needles during irrigation, as prolonged wet conditions promote fungal growth. Water at the base of the tree rather than from above.
- Maintain Tree Vigor: Healthy trees are more resistant to infections. Fertilize pines in need and ensure they receive adequate water during dry periods.
General Tips for Protecting Pines from Blight Diseases:
- Regular Inspections: Inspect pine trees regularly for early signs of disease, especially during the spring and early summer months when blight diseases are most active.
- Proper Watering and Fertilizing: Keep pines well-watered (especially during dry periods) and fertilized with a balanced, slow-release fertilizer to ensure healthy growth and improved resistance to diseases.
- Improve Air Circulation: Proper spacing between trees and thinning out dense foliage improves airflow around the tree, reducing humidity levels and minimizing conditions favorable for fungal growth.
- Remove Dead or Infected Material: Clean up fallen needles and branches promptly. Infected material can act as a breeding ground for fungal spores.
- Consider Fungicide Treatments: In high-risk areas, or if a blight disease is known to be present, consider applying fungicide treatments as a preventive measure, especially during the early growth stages of new shoots.
Conclusion:
Pine blight diseases are significant threats to the health of pine trees, particularly in areas like Eastern Ontario. The key to managing these diseases is early detection, regular maintenance, and applying proper treatment methods such as pruning and fungicide applications. Prevention strategies, including proper tree care and sanitation, can help reduce the risk of infection. By taking these precautions, you can keep your pine trees healthy and thriving, minimizing the damage caused by blight diseases.
apanese Beetles:
Japanese beetles have become an increasingly common pest in Eastern Ontario, where they pose a serious threat to a wide variety of trees and plants. These beetles are about 10-12 mm long, with shiny metallic green bodies and coppery-brown wing covers. They typically emerge in mid to late summer and feed on the foliage, flowers, and fruit of many tree species. Infested trees often show signs of skeletonized leaves—where the beetles eat the soft tissue between leaf veins—resulting in a lace-like appearance. Heavy infestations can lead to significant defoliation, stressing the tree and making it more vulnerable to other pests and diseases.
To prevent damage from Japanese beetles, early intervention is key. Regularly inspecting your trees during the beetle’s active season can help catch infestations before they become severe. Physical removal by handpicking beetles and dropping them into soapy water is effective for small infestations. Installing beetle traps may help reduce local populations but can sometimes attract more beetles to your area, so placement away from valuable trees is important. Maintaining tree health through proper watering, mulching, and fertilization strengthens natural defenses.
If a tree is heavily infested, more aggressive treatment may be necessary. Applying insecticides labeled for Japanese beetle control can reduce beetle numbers, but timing is critical—treat when adult beetles first appear for best results. Consult a professional arborist or pest control expert to select appropriate products and methods, especially for large or valuable trees. In all cases, continued monitoring and care after treatment are essential to support tree recovery and minimize future damage.
Emerald Ash Borer:
The emerald ash borer (EAB) is an invasive beetle native to Asia that has caused widespread destruction of ash trees across North America, including Ontario. Adult EABs are metallic green, slender beetles about 8-14 mm long. They lay their eggs on the bark of ash trees, and once the larvae hatch, they burrow into the tree’s inner bark and feed on the phloem—the tissue responsible for transporting nutrients. This feeding disrupts the tree’s ability to move water and nutrients, eventually leading to the tree’s death, often within 2 to 4 years of infestation.
Signs that your ash tree may be infested with emerald ash borer include thinning or dying crowns, yellowing or browning leaves during the growing season, bark splitting, and the presence of D-shaped exit holes about 3-4 mm wide on the trunk and branches where adult beetles have emerged. You might also notice serpentine galleries—winding tunnels under the bark caused by larval feeding. Woodpecker damage, where birds strip bark looking for larvae, is another common indicator.
To prevent EAB infestation, it’s essential to avoid moving ash firewood or logs from infested areas to uninfested ones, as the beetles can hitchhike in wood. Maintaining overall tree health through proper watering, mulching, and fertilization can help trees resist stress but won’t prevent infestation by itself.
For trees already infested or at high risk, systemic insecticides can be effective if applied early. Treatments such as trunk injections or soil drenches with products containing emamectin benzoate or imidacloprid can protect ash trees by killing larvae and adults. It’s best to consult a certified arborist for diagnosis and treatment options, as timing and application method are critical for success. In severe cases where trees are heavily damaged, removal may be necessary to prevent hazards and stop the spread of the pest to nearby healthy ash trees.
Construction and trees: how to avoid damaging your trees when doing construction on your property?
Protecting trees during construction is crucial to preserve their health and structural integrity, as construction activities can pose significant risks. Common threats to trees on or near construction sites include soil compaction, root damage, changes in soil grade, damage to the trunk or branches, and exposure to harmful chemicals or equipment.
Common Risks:
- Soil Compaction: Heavy machinery and foot traffic compress the soil around tree roots, reducing oxygen availability and water infiltration, which can suffocate roots.
- Root Damage: Excavation, trenching, or grading can cut or crush roots, severely affecting the tree’s ability to absorb water and nutrients.
- Grade Changes: Adding or removing soil around the base of a tree can bury roots or expose them, causing stress or injury.
- Physical Injury: Construction equipment can scrape or bruise bark, damaging the protective outer layer of the tree and inviting disease or pests.
- Chemical Exposure: Spills of concrete, fuel, or other chemicals can harm root systems and soil health.
How to Protect Trees During Construction:
- Establish a Tree Protection Zone (TPZ): Fence off an area around the tree’s dripline (the outer edge of the branches) or larger if possible. This zone restricts access to heavy machinery and foot traffic, minimizing soil compaction and root damage.
- Avoid Root Disturbance: Minimize excavation and trenching within the TPZ. If roots must be cut, make clean cuts with proper tools and consult an arborist to assess the impact.
- Maintain Soil Grade: Avoid piling soil or materials on top of root zones, and try to keep the original soil level intact to prevent root suffocation or exposure.
- Protect Tree Trunks and Branches: Use barriers or padding to shield bark from equipment and vehicle damage.
- Plan for Watering and Mulching: Construction can disrupt water flow, so provide supplemental watering if needed and apply mulch to protect roots and retain moisture.
- Consult a Certified Arborist: Have an arborist evaluate the site before construction begins and provide guidance or supervision during the project to ensure trees are properly protected.
By taking these precautions, you can significantly reduce construction-related stress and damage to your trees, helping them remain healthy and vibrant for years to come.
