Everyone jokes about the bipolar Coloradan weather, especially with the sporadic rain, storms, and heat we’ve gotten this season. But have you ever wondered what effects it has on our plants and trees? Here, we’ll talk about the three most recent tree fungal diseases confirmed in the Denver area that you’ll definitely want to keep an eye out for.
While some fungi can come in the form of fun, friendly, and even helpful aspects of our ecosystem, many can have a detrimental effect on trees and plants.
This is where ArborScape comes in; to help you learn how to recognize tree fungal diseases, and help you prevent or treat them. So let us keep you up to date on the most recent issues we’ve come across.
Tree Fungal Diseases
Let’s start with Dutch Elm Disease. After 12 years, the Office of the City Forester has confirmed the presence of Dutch Elm Disease in the City and County of Denver in the South Park Hill Neighborhood.
This tree fungal disease is transmitted by the elm bark beetle or through root grafts in the soil from infected trees to uninfected trees.
The symptoms of this develop rapidly, especially in dry hot weather when the plant is growing rapidly. This can include discoloration, wilting, and browning, or dying leaves in the upper canopy, then dieback of branches, and/or a quick death of the tree; usually within a few months to a year.
Because the risk of spreading is so high, if an infected elm is found on a property, the Office of the City Forester will issue an order to remove the tree within 14 days in an effort to contain the spread.
Disposing of the infected wood debris properly is required to prevent the possible spread, so unfortunately wood cannot be kept or stored the way we usually do (check out our sustainability policy).
There are treatment options for healthy trees that could be used in combination with good cultural practices to prevent the possible spread of the disease.
Options like trimming back wilted branches or using fungicides as a preventative to protect the bark and roots of the elm are commonly used, which is exactly what we offer here at ArborScape.
Next up we’ve got Verticillium Wilt. This is a serious tree fungal disease that persists in soil. Like the Dutch Elm Disease, this fungus isn’t such a fun guy and can infect a wide variety of plants and trees through the roots. Once inside the tree, the fungus spreads rapidly and plugs the vascular system, causing wilting leaves and even branch or total tree mortality.
You can recognize this tree fungal disease by the wilting and dead leaves on a portion of the crown of your tree that will spread to another portion through springtime.
More specifically, you’ll start to notice older leaves starting to turn yellow just inwards of the margins of the leaf while the tips can curl inward before moving onto new growth and ends with premature leaf drop.
Unfortunately, the only option to keep your tree healthy is by trimming the infected branches to stop the spread; another service offered by our arborists here.
And, of course, we can’t forget about Anthracnose, a tree fungal disease that creates dark lesions in leaves and dry curling toward the tips.
While anthracnose is considered more of an aesthetic problem, it can become much more serious if it occurs over several growing seasons.
This wouldn’t be much of an issue if it hadn’t been for all the rain and heat fluctuations over this season. Because this fungus affects the lower, inner canopy of the tree, the rain causes the fungus to rise to the new nodes in branches, causing a circular, repetitive pattern that keeps the fungus coming back for more.
This fungus usually thrives in warm, humid climates, as the rain and hot weather combination allow this particular fungus to flourish, especially in shade trees as soil can’t dry properly in the shade. So while our usually arid climate makes it difficult for this fungus to grow here, our unusual weather this season has created an environment where it can thrive.
While traditional sprays don’t work well on fungus here, our Cambistat treatment fights hard to make leaves thicker to protect the trees against this fungus. And even raking on your own can work well for controlling this, as it keeps the fungus from continuing to spread back up into the spores of the branches.
One of the main reasons these diseases run rampant is due to the surplus of precipitation in the weather. As important as water is in our dry state, there can be too much of a good thing. Balance is always key when it comes to the overall health of our trees.
So if any of these tree fungal diseases have got your worried, don’t hesitate to check out our website or call us at (303) 807-8733 for a free estimate! We have the knowledge and equipment to find a preventative option or find the right treatment to ensure your trees stay safe and healthy no matter the weather.