Tree Safety

Avoiding Tree & Utility Conflicts

  • Determining where to plant a tree is a decision that should not be taken lightly
  • Many factors should be considered prior to planting
  • When planning what type of tree to plant, remember to look up and look down to determine where the tree will be located in relation to overhead and underground utility lines

Trees & Power Lines

  • Distribution systems are required to bring utilities into our homes
  • These services arrive at our homes through overhead or underground lines
  • Overhead lines can be either electric, telephone, or cable television
  • Underground lines include these three plus water, sewer, and natural gas

The location of these lines should have a direct impact on your tree and planting site selection:

  • The ultimate mature height of a tree to be planted must be within the available overhead growing space
  • The soil area must be large enough to accommodate the particular rooting habits and ultimate trunk diameter of the tree
  • Proper tree and site selection will provide trouble-free beauty and pleasure for years to come

Overhead Lines

  • At SVEC, overhead electrical lines are the most plentiful
  • These overhead utility lines are the easiest to see and probably the ones we take most for granted
  • Although these lines look harmless enough, they can be extremely dangerous

Maintaining Trees Around Overhead Lines

  • Planting tall growing trees under and near these lines will require your utility to cut them to maintain safe clearance from the wires
  • Cutting may result in the tree having an unnatural appearance
  • Periodic pruning can also lead to a shortened life span for the tree
  • Trees that must be cut away from power lines are under greater stress and more susceptible to insects and disease
  • Small, immature trees planted today can become problem trees in the future
  • Tall growing trees near overhead lines can cause service interruptions when trees contact wires
  • Children or adults climbing in these trees can be severely injured or even killed if they come in contact with the wires
  • Proper selection and placement of trees in and around overhead utilities can eliminate potential public safety hazards, reduce expenses for utilities and their members and improve the appearance of landscapes

Underground Lines

  • Trees are much more than just what you see overhead
  • Many times the root area is larger than the branch spread above ground
  • Much of the electrical utility service provided today runs below ground
  • Tree roots and underground lines often co-exist without problems
  • However, trees planted near underground lines could have their roots damaged if the lines need to be dug up for repairs
  • Consult your tree care professional or garden center staff for assistance in choosing the tree which will have the right type of root system for the location you have chosen

Danger to Underground Lines

  • The biggest danger to underground lines occurs during planting
  • Before you plant, make sure that you are aware of the location of any underground utilities
  • Please call Miss Utility at 811 to be certain that you do not accidentally dig into any lines and risk serious injury or a costly service interruption
  • Never assume that these utility lines are buried deeper than you plan to dig
  • In some cases utility lines are very close to the surface

Proper Places for Trees Around Homes

The following illustration indicates approximately where trees should be planted in relation to utility lines. Your garden center staff or tree care professional will gladly help you select the right tree.

Tall Zone: 60 feet (20 meters); Medium Zone: 40 feet (12 meters); Low zone: 20 feet (6 meters) or less;

Tall Zone

Trees that grow 60 feet (20 meters) or more in height.

  • Larger types of trees can be used here
  • You should consider your neighbor’s view or their existing plantings of flower beds and/or trees
  • Plant large trees at least 35 feet (11 meters) away from the house for proper root development and to minimize damage to the house or building
  • Large growing trees are also recommended for streets without overhead restrictions
  • Street planting sites must also have very wide planting areas or medians [greater than 8 feet (3 meters)] which allow for a large root system, trunk diameter and root flare
  • Large trees are also recommended for parks, meadows or other open areas where their large size, both above and below ground, will not be restricted, cause damage or become a liability

Medium Zone

Trees that grow no taller than 40 feet (12 meters).

  • These trees are used to decorate or frame your house or provide a park-like setting
  • Select your trees first, then plant shrubs to complement the trees
  • Medium-sized trees are also recommended for planting anywhere the above and below ground growing space will allow for reaching a mature height of 30 to 40 feet (10 to 12 meters)
  • Appropriate soil spaces are: wide planting areas or medians [4 feet (1 meter) to 8 feet (3 meters) wide], large planting squares [8 feet (3 meters) square or greater] and other open areas of similar size or larger

Low Zone

No trees are recommended for this zone.

  • This zone extends 15 feet (4.5 meters) on either side of the wires
  • No trees are recommended in this zone
  • Only low growth shrubbery, 4 to 6 feet in height is recommended in these areas
  • Note that any trees or shrubs found in this zone are of no value according to ISA appraisal guidelines and therefore are not encouraged to be planted in this zone
  • Often when lines and equipment are utilized to maintain and work on power lines the vegetation in this zone are damaged or cut to do the work
  • Please do not plant in this zone!

Some Further Suggestions

Windbreaks

  • Plant evergreen trees on the west or north side of the house, approximately 50 feet (15 meters) or more from the house

Temperature

  • Plant deciduous (autumn leaf-dropping) trees on the south and/or west side of the house to cool in the summer and allow sun to enter the house in the winter
  • Planning before planting will help you to be sure that the right tree is planted in the right place
  • Proper tree selection and placement will enhance your property value and prevent costly maintenance trimming and damage to your home
  • Good landscaping uses shrubs and low-growing trees that are compatible with utility lines
  • Low-growing trees will not create public safety hazards or cause service interruptions to you or your neighbors, nor will they require severe pruning

If you have any questions, please contact your tree care professional, the county agriculture extension agent or our Vegetation Management Coordinators.

 6 Things You Should Know When Planting a Tree

  1.  Call Before You Dig – several days before planting, call the national 811 hotline to have underground utilities located
  2. Handle With Care – Always lift tree by the root ball – Keep roots moist until planting
  3. Digging a Proper Hole – Dig 2 to 5 times wider than the diameter of the root ball with sloping sides to allow for proper root growth
  4. Planting Depth – The trunk flare should it slightly above ground level and the top-most roots should be buried 1 to 2 inches
  5. Filling the Hole – Backfill with native soil unless it’s all clay – Tamp in soil gently to fill large air spaces
  6. Mulch – Allow 1 to 2 inch clearance between the trunk and the mulch – Mulch should be 2 to 3 inches deep

For more tree-planting tips and information, visit the Arbor Day website.

Source: Arbor Day Foundation 90075201