When to Plant
Ideally, trees are planted during the dormant season – in the fall after leaf drop or in early spring before budding. You want cool weather conditions that will allow plants to establish roots in their new location before spring rain and summer heat hits. More detailed planting information is also available online at cityofboise.org/cityoftreeschallenge in the Treasure Valley Tree Selection Guide.
Quick Tips for Planting Your Tree
- Identify the root collar [see page 7 of Treasure Valley Tree Selection Guide] – This is where the trunk expands at the base of the tree. You want this area to be visible after the tree has been planted, so remove any excess soil on top of the root ball.
- Dig a shallow, broad planting hole. The hole should be two to three times wider than the root ball of the tree, but only as deep as the root ball.
- Remove containers or cut away the wire basket around the tree trunk. Inspect your tree’s root ball for circling roots and straighten, cut or remove them.
- Place the tree at the proper height – Take care to dig the tree hole to the proper depth (as deep as the root ball, with trunk flare exposed) – and no more. When placing the tree in the hole, lift it by the root ball and not the trunk.
- Straighten the tree in the hole. Before filling with soil, straighten the tree and secure with one or two stakes if needed to hold it upright. Gently backfill the hole with soil once the tree is placed and use water to settle soil around the root ball.
- Fill the hole gently but firmly with soil. Pack soil around the base of the root ball to stabilize it. Don’t be afraid to get your hands dirty! Remove any support staking and ties after the first year of tree growth.
- Mulch the base of the tree. This will help prevent damage to the root ball and trunk, reduce grass growth and weed competition around the tree. A two to four-inch layer on top of the covered root ball and trunk flare is ideal. Avoid fertilization at the time of planting.
- Provide follow-up care. Keep the soil moist but not water-logged. Water the tree at least once a week (rain can supplement).
- Call Community Forestry with questions. The City of Boise’s arborists are available to answer questions and provide insight into tree planting and care. Call (208) 608-7700 for assistance or visit cityofboise.org/forestry for online tree information, including instructional videos.