City of Boulder, CO

06/10/2019 | News release | Distributed by Public on 06/10/2019 11:32

Tree Planting Instructions

March through May and September through October are ideal times of the year to plant trees on your property. It is less stressful on the tree to plant when it's not too hot, dry or cold.

Whether you have just purchased a tree from a local nursery, from a City of Boulder Tree Sale, or are interested in how to plant a future tree, please review these steps to make sure your tree is planted correctly.

Select the Right Tree for the Right Place

  1. Evaluate your space. Decide how tall and wide you want your tree to be when it reaches maturity. 
  2. Consider landscape characteristics such as soil type, irrigation, sunlight exposure, existing trees, and overhead or underground utilities.
  3. Help make Boulder's canopy diverse and resilient. Select a different tree than what's already in your yard and surrounding properties.

Step-by Step Tree Planting for Container Grown and Balled and Burlapped (B&B) Trees

  1. Call Colorado 811 before you dig.
  2. If the site is clear of utility and infrastructure conflicts, dig planting hole 2 x the diameter of the root ball and no deeper than the location of the root flare (location where the roots begin to extend outward from the trunk.)
  3. Locate the root flare by gently removing any excess soil piled on top of the root ball until the location roots begin to extend from the trunk is fully visible. It is very common for soil to be piled up over the root flare, but it is easy to remedy!
  4. If planting a container grown tree, remove the tree from the container and use a hand saw to cut the outer 1-1 1/2'' of soil and roots. This step is done in order to remove any roots that may have been circling the container. If thee roots are not removed, they will continue to grow in a circle, rather than outward. This will eventually girdle the tree and lead to premature decline. Place tree in planting hole.
  5. If planting a balled and burlapped (B&B) tree, gently remove bottom 1/3 of wire basket and burlap and place tree in planting hole.
  6. Check planting depth. The root flare you located earlier should be 1- 1.5'' above the grade of the planting hole. Add more soil beneath root ball as needed. After this stage, remove all remaining wire, twine and burlap on your B&B tree.
  7. Gently backfill native soil into the planting hole, careful to not bury the root flare. Do not add amendments and do not compact the soil. Compact soil will not allow water to infiltrate.
  8. Using any excess soil, create a berm around the outer edge of the planting hole. This berm will help retain water during watering or rain events.
  9. Water the tree slowly, add additional soil if settling occurs. The soil should be moist but not overly saturated.
  10. Mulch the tree with wood mulch inside the berm to a height of 3'. Do not pile mulch on trunk, making sure to leave a 1' gap between mulch and trunk.
  11. Stake your tree. Place two 4'-5' tall wooden or metal stakes opposite each other against prevailing winds. Stakes should be 1.5 feet away from the tree or placed just outside of the berm. Use soft canvas or nylon straps, with the flat side resting on the trunk of the tree, to tie the tree to the stakes. Tie only as high as necessary to stabilize the tree and make sure that they are not so tight as to restrict movement.
  12. Remove stakes and ties after 1 year.