Poplars, Cottonwoods and Aspens are all members of the Populus genus and have many characteristics that make them a desirable feature in homeowners’ yards. These attractive trees have triangular leaves with long stems and silvery backsides that shimmer or quake in the wind. Moreover, Cottonwoods and Poplars are softwood trees that grow fast. Their ability to produce shade quickly is why homeowners planted the trees extensively in the 1960s and 1970s around Denver and its suburbs. However, the lifespan of Poplars and Cottonwoods is about 50 years, so many older neighborhoods around Denver are starting to see many dead or dying Cottonwoods and Poplars.
Old age is not the only reason Cottonwoods and Poplar trees die. By the end of May, trees are leafing out and in full bloom, and like any tree, a late-spring hard frost can damage Cottonwoods and Poplars. By the end of May, trees are leafing out and in full bloom. The trees’ vascular system is vulnerable to hard freezes, which can shock trees back to hibernation. If a frost in May hits your trees, water them and keep your fingers crossed. The trees will survive if they re-bloom in July. If not, most likely the frost killed them and you will need to remove them.
Poplar Tree Diseases
A common Cottonwood and Poplar tree disease is Cytospora Canker. The fungus attacks weakened trees affected by drought, late-spring frosts, insect and fungi defoliation, or trunk and root injury. The fungus spreads across the living bark and wood of the tree. If not treated, the tree dies from girdling. The appearance of oozing cankers is a sign that a tree has Cytospora.
Since Cytospora Canker thrives on stressed and weakened trees, the best prevention approach is to reduce stress factors. Wounds caused by lawnmowers and weed trimmers are common stress factors. So, protecting trunks or better lawn equipment operating practices will reduce trunk injury. Insects, such as Oystershell Scale, stress the tree and make it susceptible to Cytospora Canker. Controlling Oystershell Scale and other tree pests will reduce harm by the Cytospora Canker.
Mature Cottonwood or Poplar trees tend to be large trees. As they die, large branches break off, which are hazardous to people, homes and yards. So, it takes a professional that has the right trucks, equipment and man-power to remove large trees. Ross Tree Company can remove the largest Cottonwoods found in the Denver area. We will handle any permits needed for road closures or large equipment that’s needed to remove large branches and trunks from the property. For a Cottonwood or Poplar tree assessment, click here to fill out a tree service request form or call (303) 871-9121.