No matter the type of trees you have on your Austin property, you need to pay close attention to them and ensure that they are healthy and free from both disease and infestations. This is particularly important on fruit trees since you likely want to consume the fruit and that isn’t possible if the tree is unhealthy to the point where it simply doesn’t grow. Austin residents love growing Bradford pear trees since they do well in this climate and produce delicious fruit, but one of the most common issues affecting them is fireblight.
Simply put, fireblight is a type of bacterial disease that will kill the shoot of your pears. It also affects apples and other related ornamental trees. The result is a tree or plant that looks as if it has been scorched by fire, giving this disease its name. It is caused by a bacterium and typically occurs between late spring and autumn. Fireblight won’t affect stone fruits like peaches, nectarines, cherries, or plums, just those within the family of Rosaceae and sub-family Pomoideae.
Fireblight is native to the North American continent but has actually spread to some other areas. The bacterium causes fireblight when it gets into the inner bark of the tree, which it typically does through the blossoms of the tree. The bacteria that cause fireblight are typically spread by insects like bees or wind-blown rain. The infection can spread incredibly quickly in the right conditions, traveling as much as two inches each day. The infection’s severity is affected by things like insects, wounds, humidity, and temperature.
An arborist can easily diagnose your Bradford pear tree with fireblight, but the average person will be able to spot many of the signs that indicate this may be a problem. If it is flowering time and your blossoms wilt and die, this is a good indication. When the weather is wet, infections in the tree may produce a white liquid that is slimy. Eventually, the infection will spread along the inner bark, at which point the shoots can shrivel up and die. During this short time with active spread, the outer wood of your pear tree will be a foxy brown shade if you peel back the infected brown. It is also common to spot cankers, those areas of bark that is dead and sunken, on the branches of infected Bradford pear trees, particularly in the areas where large branches connect with infected shoots.
You may be able to catch fireblight in the early stages if you notice water-soaked spots that are dark green and found on the tissue that has been affected. It is most likely that the bacteria causing fireblight enter your Bradford pear trees through the natural openings like nectaries or stomatas, blossoms, or wounds. If not caught promptly, then the above symptoms will appear. The average person is unlikely to notice these early signs of fireblight but an arborist can catch them. You would, however, have to realize that something is wrong with your tree and hire an arborist in the first place.
The first thing you should do if you notice fireblight on your Bradford pear tree is to contact an arborist. They will be able to confirm that you do in fact have fireblight and ensure that there aren’t any other issues affecting your tree as well. Since arborists have training and experience in caring for trees, they will also be able to recommend the ideal course of action. That being said, they are likely to recommend certain methods, such as pruning.
To prevent fireblight from spreading throughout your Bradford pear tree or even to other adjoining trees, you want to prune the infected areas as soon as possible. Be sure to always wipe your pruning tools using a disinfectant of some sort between every cut; otherwise, you may accidentally spread the disease to healthy portions of the tree. While making the cuts, you want to peel back the tree’s bark so you can see the brown staining. From there, you can cut back about one foot in smaller branches to reach the healthy wood, but larger branches will require larger cuts of about two feet. After pruning the infected portions of the pear tree, burn the so the bacteria doesn’t spread. You should also remove any of the late blossoms before they get the chance to open.
If possible, avoid pruning back the infected portions of the tree during the spring since this is when the bacterial ooze is highly abundant, increasing the risk of infection. When you are pruning the tree, take the opportunity to remove the cankers as well. This part should ideally be done in winter, leaving at least an inch of healthy bark along the sides and three or four inches on the ends. Once again, always disinfect your tools between every cut.
To further control fireblight, try to prevent succulent vegetative growth, which can occur due to heavy fertilizing or poor drainage in the spring. If feel the need to fertilize your plants and trees, do so in the fall to avoid succulent vegetative growth. Remember that excessively pruning can also lead to lush growth.
People tend to turn to chemicals as the answer for various problems, but this is not an effective option against fireblight. In most cases, spraying will improve the problem slightly, but just waste money over all. It will typically be more affordable to just replace a severely infected tree than to use chemical sprays that don’t guarantee results.
If you have Hawthorn hedges on your property, you should be aware that they sometimes provide the source of the infection. That being said, it is still possible to keep them on your property and avoid fireblight with the help of an arborist.
Luckily, Bradford pear trees tend to be reasonably resistant to fireblight. That being said, it does still pose a risk. You can minimize the chance of your trees contracting it by ensuring that the trees are free from stress and healthy.