Trees require love, care, and attention. This can mean being on the lookout for pests to protect the trees’ health. Which also means that you need to be aware of these pests and know the signs and symptoms of a sick tree. If you manage to catch these pests in time, you can save your tree from certain demise. Our team at Five Star Tree Services want to go over some fungal tree pests to watch out for and treatments for each.
Tar Spot
This is a fungal disease that is brought on by Rhytisma acerinum. You can recognize this disease from the ridged, dark spots found on the leaves of a tree. The silver maple is particularly susceptible to getting tar spots.
Signs & Symptoms
You will start to notice yellow spots forming on the leaves in the early summer. These spots will then turn darker, and look tar-like, usually about half an inch wide, as the summer progresses. If you look at them closely, the spots will be raised and the leaf under it will be curved. These spots are actually the fungus holding its spores. What happens is that the fungus lived through the winter on dead leaves on the ground. When spring comes around, spores are released into the air and land on new leaves, and thus the cycle goes on and on each year.
How to Treat It
Thankfully this disease won’t kill a tree, but some leaves can end up falling early. To help prevent the spread, you can gather all the leaves in the fall and either get rid of them or destroy them. You can also get commercial fungicide.
Black Knot
This is another fungal disease that is brought on by Apiosporina morbosa. Cherry and plum trees are particularly susceptible to getting this but also apricot, flowering almond, and peach trees can get it as well.
Signs & Symptoms
Any wounds or newly growing twigs are the entry points for this fungus, where it will infiltrate, grow, and infect the tree. Once infected, over the course of a year, you will notice hard, rough, black knots where it has been infected by the fungus. They can grow to 15cm (about 5.91 in) long over the side of a twig, but they have also been known to engulf the entire twig. Once a twig is infected, the fungus will eventually spread to the branches and trunk of the tree. This will cause large wounds on the bark that you can see with spiral fissures. During the spring, you can see soft, olive-green spores covering the knots. They become airborne and infect neighouring trees for many kilometers. It’s possible for trees to continue to live, even if covered by black knots. But the aesthetics of the tree diminish considerably.
How to Treat It
Wait until the tree is dormant (late fall to early winter), get sterile equipment, and prune all the infected twigs and branches. Make your cuts as far from the knot as possible and destroy all your trimmings. Don’t forget to sanitize your tools before using them again, otherwise you could spread the disease back to your plants. If you have a tree fully engulfed in black knots, the best thing to do is remove the tree completely and destroy it.
Anthracnose
This is yet another fungal disease that is brought on by Aureobasidium apocryptum and other species of Gloeosporium. This is a leaf blight that is particularly fond of all maple species. It seems the most susceptible to it is the sugar maple. But it also targets ash, oak, ironwood, basswood, and sycamore. Early spring is when it spreads, through spores from dead, infected, leaves on the ground. It’s ideal weather to thrive in is cool, cloudy, and wet days that go into June.
Signs & Symptoms
Mid-May is when you can notice the first symptom. Throughout the growing season, the fungus can continue to spread. You can notice infected leaves due to their light brown spots and blotches by the main veins and leaf margins. These leaves can curl up, wither, and fall prematurely. On the bottom face of the leaf, you can notice small, cream-coloured spores growing close to the main veins. This fungus produces similar symptoms to leaf scorch. To distinguish between the two, look for spores to identify the fungus from the scorch.
How to Treat It
When fall comes around, rake up all the leaves and destroy them. If a tree has been severely diseased for many years, you should root feed it. Root feeding is a fertilization method where holes are bored around the trunk of the tree and fertilizer is then inserted into the holes. This helps the tree absorb the fertilizer faster and better. If you are still worried about your tree, you can use a spray, but this is not usually necessary. Spray zineb or ferbam three times during the time before your tree buds are opening and developing foliage. Once they have opened, you can spray twice bi-weekly.
How Five Star Tree Services Can Help
Trying to battle all these pests can be tricky and time consuming. Our team at Five Star Tree Services can help! With our wide variety of tree care services in Toronto, help is just a phone call away! You can reach us at (416) 990-3355!
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