People tend to think of plants and trees as the most low-maintenance types of living beings. While this is probably true, there’s still a big difference between “low maintenance” and “no maintenance.” On top of just ensuring that your trees have the basic necessities (water, nutrients, and sunlight), you also need to be on the lookout for diseases that can infect your trees. Some vegetation diseases can be deadly to your entire landscape if they’re not found and treated early enough. At Turf Shield, we go beyond lawn care to actually educate our clients about their plant life, and in this effort, we’ve pulled together the basics you need to know about the most common tree diseases in the Atlanta area.
Caused by a fungus, seiridium canker creates open cankers that leak resin. It’s often noticed when homeowners see individual branches and limbs begin to die on their tree. The fungus is spread to different branches within a tree or from one tree to another when the spores travel in water, either from the rain or from irrigation. Trees are more susceptible to being infected if they’re already weakened by draught and excessive heat. Unfortunately, there are not currently any fungicides that can treat seiridium canker after it has infected a tree, so the only treatment is to reduce the spread by pruning your trees to remove infected branches and by irrigating when the weather is dry.
There are different types of root rot that are each caused by their own unique fungus. As a group of diseases, though, root rot infects the tree roots, causing the wood to become spongy and sometimes leading to mushroom growth at the base of the tree. These mushrooms are often the only way homeowners discover root rot. The fungus is soil-borne and is most likely to spread and infect trees when the soil stays too wet for too long, and it can take hold of weaker, less healthy tress more quickly. The best way to lower your risk of root rot is to manage the excessive soil moisture by creating appropriate drainage, but if one or more of your plants do develop root rot, it can often be treated with specific fungicides.
We’ve all seen mildew on a shower curtain or a forgotten piece of damp fabric, and powdery mildew has a similar appearance. It causes your plant’s leaves to develop scattered gray spots, and it can be spread rather easily when the spores become airborne. Like root rot, powdery mildew is really a category of diseases, with different forms of powdery mildew being caused by different varieties of similar fungi. Unfortunately for Georgia, humidity makes this disease far more likely. You can take preventative steps in your lawn by increasing air flow through your plants to reduce humidity (such as by pruning selectively or by spacing plants out farther). If you do notice the telltale gray spots on your plants, the infection can often be treated with professional fungicide treatments for lawns.
The symptoms of botrytis blight can look similar to those of other tree diseases – spots on leaves and flowers, cankers on stems, crown rot, and wilting, as well as lumps of fuzzy, brown/gray spores with thin black stalks. Caused by a certain type of fungus, botrytis blight spreads through the air and the water, as well as on insects, so it can be rather difficult to control. You can limit your plants’ risk for botrytis blight by improving the air flow to reduce humidity, and by using preventative fungicides when moist, humid, cool, and cloudy weather conditions raise the risk for infection.
While many of the other tree diseases are caused by fungi, fireblight is caused by a specific strain of bacteria, and it affects members of the Rosaceae family, like pear trees, crabapple trees, and their relatives. The primary sign of fireblight (and the reason it gets its name) is an almost burned appearance at the end of branches and twigs. In some cases, the branches may bend in a hook-like shape. Fireblight spreads most during warm, wet weather, so it’s most common between April and June. If you think your plants are infected, prune out the infected branches about 6 inches below the damage, disinfecting your shears between each cut. Steer clear of fertilizer with too much nitrogen in the summer as well.
When you set up or revitalize your landscape, you put a lot of work, time, and money into building the perfect arrangement of trees, shrubs, flowers, and other plants. Any of the diseases above (and many more) can jeopardize everything you’ve invested into your landscape. When it comes to tree diseases, prevention is the #1 goal, and whether you still have a healthy lawn or you’re fighting an existing infestation, our lawn care professionals at Turf Shield are happy to help. To get started, schedule a consultation with Turf Shield lawn care professionals, and be sure to follow us on social media as well for more lawn care tips.