Ash Tree Removal
Over the past few years the Emerald Ash Bore has been spreading across Vernon Hills feeding on and consequently killing all the ash trees. As these trees die we are working hard to remove them in a timely manner. As of the writing of this report, Spring of 2016, we are about 60% through the ash removal and plan to be 100% by the end of the winter 2016/2017. For more information on EAB, the following link will connect you with the Illinois Department of Agriculture’s website concerning EAB. https://www.agr.state.il.us/eab/
Additional Tree Removals
In addition to the ash tree removals you may see other trees being taken down. Around our lakes there are numerous Willow Trees that we are starting to remove, this is due to the trees reaching the end of their life span and in a state of decline. As Willows decline they start to fall apart, the wood is weak and rots very quickly. We take down trees that are accessible from our bucket truck, others are contracted to be removed. Trees around our lakes and ponds will be replaced with the following guidelines in mind. 1) If there is a slope going towards the waters edge, a smaller ornamental tree will be planted that can be pruned and managed from the ground level. Maximum mature height of these trees will be around 15 feet. 2) If there is minimal to no slope going to the waters edge, a larger shade tree or specimen tree will be planted, with a level surface we will be able to trim up the tree using our bucket truck.
Austrian & Scotch Pine
You may have noticed recently that many of our pine trees in and around the parks have been starting to die, we noticed that too. Samples were taken and sent to the University of Illinois Extension Service for testing. Results of those tests revealed that two different types of fungi were present on the needles, one that attacks new growth and one that attacks older growth. There is no feasible treatment for these fungi. Most of the damage from these fungi show up in the winter to spring transition period. Another factor at play is the age of these pine trees, many of them are approaching +30 years which is when these trees tend to start to decline due to their inability to deal with our hot dry periods in the summer. These trees will be removed as they die or become unsightly.
Pioneer Trees are trees that are first to fill in land that has been let to go and no longer are mowed. These trees tend to be fast growing, have weak wood, poor canopy structure and produce high amounts of seeds that germinate quickly. Examples of these trees are Cottonwood, Boxelder, Black Locust and Mulberry trees. Some tree lines bordering our parks will continue to have pioneer trees in them as these areas are not our focus of improvement at this time. In the main sections of our parks these trees will be slowly but surely cleared from the parks and replaced with quality trees that are spaced appropriately.
Trees start to die for various reasons such as end of lifespan, disease, insects, weakened structure due to fungal activity, etc. Unfortunately even the good trees need to be removed from time to time.
Trees will not be replaced one for one. Many trees were planted too close together, an old practice that has been recognized as not healthy. Trees planted too close together eventually start to compete for water and nutrients leading them to start to struggle. Air flow in the canopy is reduced as well, inviting diseases to set in. Trees will be spaced on average 50 feet apart.
Trees have certain environmental factors that they prefer in order to grow well and stay healthy. Each tree that is chosen is researched to determine where they would be more productive / healthier and locations in the parks are chosen for those trees that best fits their preferences and requirements. Likewise, trees are hand picked at the nursery to ensure we are getting the best trees available with the best branching structure.
As unfortunate as it is that to have lost so many trees and need to remove so many others, it does provide us an opportunity to introduce many new and rarely planted trees that are hardy to our area.
In 2016 (65) new trees were planted, (23) of which were new species / varieties that didn’t exist in our parks before. (8) of the (65) were trees donated as memorial trees.