The planting season in Portland extends from October 1 through April 30. Planting during this timeframe is recommended.
Planting during the summer months (May 1 through September 30) is not recommended. Trees planted during the summer months should receive extra watering as needed to ensure tree survival and establishment.
If a non-development permit is issued outside of the planting season, planting may be deferred until the next planting season in order to promote survivability. Talk to your Tree Inspector about deferring planting until the planting season.
Tree Size Requirements
Newly planted trees must be a minimum caliper size as defined below. This is to encourage planting large caliper trees, which have more desirable established structure and are less prone to vandalism.
Tree caliper is the trunk diameter measured 6 inches from the ground; if caliper is greater than 4 inches, the caliper measurement is taken at 12 inches from the ground.
Broadleaf Tree Size Requirements:
|Development type||Street tree minimum caliper size||Private tree minimum caliper size|
|One and two family residential||1.5”||1.5"|
Conifer Tree Size Requirements:
Conifer trees must be a minimum of 5 feet in height at time of planting.
Tree Species for Planting
Street tree species for planting must be selected from the Approved Street Tree Planting List that corresponds to planting site conditions.
Trees on the nuisance list may not be planted as street trees or on private property.
Minimum Requirements for a Replacement Tree
Replacement trees must:
- Grow on average to at least 16 feet or more
- 1.5” caliper, single stem
- Not be an invasive species (nuisance tree) on the Portland Plant List
- Not be prone to fatal pests or diseases, such as Dutch elm disease
- Technically be a "tree" not a shrub /other, thus cannot substitute for a tree*
*Common species that are not "Trees" but are asked about: arborvitae, vine maple, dwarf varieties of Japanese maples
While there are no specific species that must be selected for planting trees on private property, the link above represents the basic requirements for replacing private trees and links to additional resources.
Oregon Utility Notification Center
Call Before You Dig, its free!
The Oregon utility notification locate center will mark the locations of underground utilities so the tree planting location can be determined. You can request a utility locate one of the following ways:
- Call 811 or 503-246-6699 (local) or 1-800-332-2344 (toll free)
- Submit a request via the Dig Safely Oregon website
Street Tree Planting Standards
Proper planting and establishment are key factors in maximizing long-term tree survival as well as the benefits of trees.
It is crucial to carefully select trees for planting that have good form and are free from insects, disease, damage, and decay.
Visit this page to see a list of tree nurseries that self-identify as selling trees to the public that meet minimum size requirements.
Following these planting recommendations will increase your tree’s chances of survival and maximize its future health. Before you plant, check for underground utilities by calling the Oregon utility notification locate center hotline at 811 or 503-246-6699 (local) or 1-800-332-2344 (toll-free).
List of non-development planting programs, such as Friends of Trees.
Proper establishment care is essential to a tree’s long-term health and survival.