Many different diseases can cause problems for your beautiful trees. If you know what to look for, you can understand which problems are serious and which can be ignored. Below is a brief summary of what to look for.
Emerald Ash Borer
Emerald ash borer larvae feed in the outer sapwood of ash trees and can rapidly girdle stems and branches. Trees often die within one-to-three years following the initial attacks. Emeralds (Diamond Bark) are affected by dying branches, wood Pecker holes, shoots at bottom of tree, D shaped holes, borers travel in firewood and bug looks metallic green and smooth. It affects trees in southern Ontario. Pull bark back and look for S pattern.
Common Tree Pests
• Ash flower fall
• Fall web worm
Pines
Pines are mostly affected by white pine blister rust or fungus Asia, white pine weevil, cancer blister resign, two fungal diseases, tip blight (small black spots on cones or needles)
Common Tree Pests
• White pine blister rust
• Winter browning
• Forms root rot
• White pine weevil
• Spruce spider mite
Maple
There are several damaging maple tree diseases and pests. Some of the most common are Verticillium Wilt fungus, which show wilt and scorched-looking leaves, another is Anthracnose, which shows extensive defoliation, shoot dieback, and twig death. Tar Spot damage causes large, tar-like spots on the leaves. Others include Asian Longhorned Beetle, root rot, gall mites, cankerworms, aphids, cottony scale, petiole borers, leafhoppers and boxelder bugs.
Common Tree Pests
• Maple gall mites
• Cottony maple scale
• Norway maple aphid
• Die back of hard woods
Birch
A few of the most common birch diseases are the Bronze Birch Borer showing winding galleries beneath the bark in the trunk and thinning at the top of the crown of the tree, Birch Leafminer larvae show green spots on the leaf surface in May or June, European Birch Aphid and the Common Birch Aphid suck the sap out of the birch tree leaves causing them to yellow and twist. Others include Birch canker, Scorch and Heart rots.
Common Tree Pests
• Birch leaf miner
• Birch skeletonizer
• Birch bronze borer
• Yellow necked caterpillar
Roots
Fungi can attack the roots of a tree, and make control virtually impossible. It is wise to identify those trees affected by root pathogens so that resistant replacements can be sought for future plantings. The most common problem is root rot.
Elm
Elm trees have battled against Dutch elm tree disease for decades, reducing the number of these beautiful trees. If you have or plant an elm tree, regular monitoring for symptoms of Dutch elm tree disease is critical to its life. Keep these disease-prone trees as healthy as possible through regular tree pruning, watering and using elm tree fertilizer.
Common Tree Pests
• Elm barek beetles
• Elm leaf beetles
• European fruit lecanium
• Dutch elm disease
• Spiny elm caterpillar
Cedar (eastern white)
Cedars are majestic, evergreen trees that include different genera and species. Their fragrant needles take the place of broad tree leaves, and offer protection as privacy screens and windbreaks. Sometimes cedar trees succumb to fungal diseases that cause them to die from the top down as nutrition is cut off to their extremities.
Common Tree Pests
• Cedar (abor-vitae) leaf miners
• Cedar apple rust
Please be aware, the following plants are dangerous to humans:
Poison Sumac
Poison sumac is a native shrub or vine found in southern Ontario. The sap of this plant contains the allergen urushiol. The chemical is released when plant tissue is damaged. Humans are highly sensitive to allergic reaction, although at least one exposure is needed for sensitization. Mild to severe inflammation of the skin can result from exposure to poison sumac.
Poison Hogweed
The clear watery sap of Giant hogweed contains toxins that can cause severe inflammation of the skin. You can get severe burns if you get the sap on your skin and the skin is then exposed to sunlight. Symptoms occur within 48 hours and consist of painful blisters. Purplish scars may form that last for many years. Eye contact with the sap has been reported to cause temporary or permanent blindness. Coming in contact with Cow parsnip and Wild parsnip can cause similar reactions.
Poison Parsnip
There is an ongoing problem in many areas of Canada with persons being injured through contact with the Wild Parsnip weed. Wild parsnip is of concern because humans develop a severe skin irritation from contact with sap from the plant. Wild Parsnip burns usually occur in streaks and elongated spots, reflecting where a damaged leaf or stem moved across the skin before exposure to sunlight. If the sap gets into the eyes, it may cause temporary or permanent blindness.
Poison Oak and Ivy
Over 50% of people in Canada are sensitive to poison ivy and poison oak. Within 12 to 72 hours of touching either of these plants, you could develop a very uncomfortable, itchy, and unsightly red rash accompanied by swelling and blisters.
The itch-inducing ingredient is urushiol. It’s an oil that’s contained in the plants’ leaves, stems, and roots. Urushiol sticks to anything it touches. So if you pet your dog or hop on your bike after they’ve brushed up against a poison oak shrub, you could end up with a rash. In addition, if someone is burning the plants and you’re close by, airborne urushiol can land on your skin and cause an itchy breakout.
Dangerous Trees and Hazards to Watch For
• Mushrooms on tree bark
• Black or rotting bark peeling
• Dead wood
• Trees with unusual leaning
• Frass or matter at bottom around trunk
• Exposed roots (new construction)
• Digging around or damaging roots
• Location and soil ground conditions