All About Trees

Trees are an important part of our community. Having trees within an urban setting supports a reduction in stormwater treatment, prolongs the life of pavement, improves mental and physical health, improves safe driving habits, and is even known to reduce crime. Allowing residents to have access to trees, green spaces, and parks promotes greater physical activity, and reduces stress, while improving the quality of life within our city.

The Iowa DNR in partnership with the USDA and Iowa Urban Tree Council has assembled information (Community Benefits from Public Trees in Iowa) highlighting how properly caring care for trees provides a wide variety of benefits to people, communities and the economy. Our urban trees make Iowa communities stronger and healthier.

Tree City USA


The City of Pleasant Hill has been a recognized “Tree City USA” community since 2003. The national Tree City USA program is the framework for community forestry management for cities and towns across America, recognizing efforts of continuous and systematic management of urban trees. The City received this recognition by demonstrating a commitment to caring for and managing our public trees.

The city has also been received a Tree City USA Growth Award for six years, showing substantial improvement to the community’s urban forest by establishing a city arborist, developing a tree inventory, improving tree protection & preservation policies and practices, and hosting community education and outreach programs.

Trees on Public Property


If you have concerns about conditions, maintenance, safety of trees at city parks, or on city right-of-way, contact Heath Ellis with Parks & Recreation at hellis@pleasanthilliowa.org or 515-309-0049.

Emerald Ash Borer


Emerald Ash Borer (EAB), an invasive beetle that kills all species of ash trees, has been confirmed in Polk County. It is native to Asia and was likely introduced into North America via cargo ships or planes. The beetle is bright metallic green in color and is visible to the naked eye, but is about the size of Abraham Lincoln’s head on a penny. The adult beetles eat ash foliage, but cause little damage to the tree. It is the larvae that cause destruction. Larvae feed on the inner bark of ash trees, preventing delivery of water and nutrients to the tree, causing it to die.

Emerging Threats to Trees


EAB is only one of several other emerging threats to Iowa’s forest communities. In a 2013, the DNR identified five key pests that have emerged and created a severe threat to Iowa’s native woodlands and community trees. The key pests identified in addition to EAB are:
  • Gypsy Moth - Feeds on over 300 species of tree leafs during the summer growing season.
  • Bur Oak Blight (BOB Tubakia spp.) – A newly named disease that can cause severe defoliation, leading to mortality of branches or entire trees, caused by a species of the fungus Tubakia.
  • Thousand Cankers Disease of Black Walnut (TCD) – A walnut twig beetle (Pityophthorus juglandis) that carries a fungus (Geosmithia morbida) spread as the beetle tunnels through tree tissues. Some experts believe TCD has the potential to decimate black walnut trees in the same way Dutch elm disease and emerald ash borer has destroyed their hosts.
  • Asian Longhorned Beetle (ALB) – Exotic pest native to China. The larva of this beetle kills trees by tunneling through the tree, which girdles stems and branches. The beetle prefers to attack maple species (Acer spp.). In some cases they will also attack birch, elm, horsechestnut, and Ohio buckeye.
Proper woodland and community tree management is the best defense against these threats. The best insurance is to maintain a diversity of tree species; while assuring an appropriate number of trees are growing on each acre. The best management tool is for communities to create diversity by not having more than 10 percent of any one species represented.

Private Ash Tree in Pleasant Hill


In 2008, Parks and Recreation conducted a community ash tree inventory sampling. An estimated 920 ash trees are located on private property in Pleasant Hill (excluding commercial sites). The diameter-at-breast-height (DBH) of these ash trees vary upon location in the city.
  • Approximately 773 ash trees with DBH between 12 and 18 inches are primarily located south of University Avenue and west of Highway 65.
  • Approximately 143 ash trees (with smaller DBH) are in the newer developments of the city.
  • An estimated cost for tree removal and replacement ranges from $500 to $2,000, depending on size and location.

Plant Some Shade


Each spring and fall the Iowa DNR and MidAmerican Energy sponsor the “Plant Some Shade” tree distribution program available to residents with a diverse selection of high quality nursery trees at a reduced price.

Public Ash Trees in Pleasant Hill


Inventory of ash tree's on public property was conducted by city staff in 2008. The city had 48 ash trees averaging 16 inch DBH. The majority of these 22 trees were located in Sunrise Park and Oakwood Cemetery. In preparation for an EAB infestation, the city has incrementally removed three ash trees per year since 2008. As of 2016, there are 24 ash trees remaining on public property.

Other Resources


A variety of resources are available to assist residents in managing trees. Follow the links below for additional information.

Tree Benefits

Trees and Natural Areas

Tree Care Resources


  • Young Tree Pruning Program: Learn the proper ways to develop a preventive pruning program for young trees.
  • Woodland Improvement and Crop Trees:Learn how healthy woodlands provide multiple benefits through stewardship.
  • Tree Pruning Cue Card: Learn how to appropriately prune crowns and roots so they are stable and healthy.
  • Pruning Established Trees Cue Card: Learn how to prune established trees to develop and maintain a dominant leader with branches.
  • Pruning at Planting Cue Card: Learn how to prune trees upon planting to correct poor structure by shortening upright stems.
  • How to Properly Prune Fruit Trees: Watch video to learn why fruit trees are pruned to cut out cellulose (wood) so the tree doesn't put its energy into it by maintaining and producing branches, but instead puts energy into producing carbohydrates in the form of fruit (fruit sugars).
  • Training Young Trees: Watch Video to learn why trees are assets, how they provide value to your property and why it's important for early structural training.

Tree Management


Pleasant Hill Parks & Recreation manages 88-acres of woodland, and over 1,300 public trees, with over 50 different species. Trees can provide a multitude of benefits to the community, and sound management allows communities to best take advantage of these benefits.

trees

Tree Pruning


Winter is the ideal time to prune trees because the leaves are gone and it’s easy to see branching structure. There is also less chances of transmitting diseases or attracting insects to fresh pruning wounds. Pruning off unwanted branches provides the tree with extra energy reserves to support new growth on the remaining branches when spring does arrive. Click here for information on pruning young trees.