Sourcing the Best of the I-5 Corridor

The Grading Protocol

A tiered verification system designed to differentiate between commodity nursery stock and the limited-edition specimens and grails of the Pacific Northwest.

Grade: 01

Standard

Sourced directly from the current availability lists of our primary nursery partners. Verification relies on the long-standing regional reputation and internal quality control of the grower. Ideal for high-volume screening and foundational plantings.

Sourced by Institutional Reputation and Nursery Quality Control
Grade: 02

Specimen Estate

Hand-selected by nursery principals for the Tree Supply Co. network. Each tree undergoes an in-person audit against the 10 Criteria of Tree Selection, verifying superior character, form, and visual impact before inclusion in the network.

Verified by In-Person Audit and Principal Selection
◆ Specimen Estate
2026 Varieties
Bloodgood Maple Sango-kaku Maple Inaba Shidare Viridis Laceleaf Red Dragon Autumn Gold Ginkgo Southern Magnolia Crape Myrtle Blue Atlas Cedar Italian Cypress Chinese Pistache
Grade: 03

Legacy Grails

Reserved for the finest of the Pacific Northwest — unique, long-lived, and monumental candidates for a living Catalog d'Raison. Buyers receive a dedicated Curatorial File including 360° high-fidelity video and drone photography prior to purchase.

Defined by Curatorial Audit and a Full Media Briefing
✦ Legacy Grails
2026 Varieties
Ancient Olive
≥36″ trunk girth
Coast Live Oak
≥4″ caliper · 48–96″ box
Tamukeyama
≥5ft canopy · multi-tier form

The 10 Criteria

Selection Criteria for Estate & Legacy Grades

01

Visible Flare: Root collar must be at or above soil line. Zero tolerance for buried trunks.

02

Self-Supporting: Specimens must remain vertical without nursery stakes or external support.

03

Clean Architecture: Rejection of co-dominant stems or structural "V" crotches susceptible to splitting.

04

Zero Trauma: No evidence of mower scars, trunk-girdling ties, or improper pruning stubs.

05

Balanced Canopy: Verified 360° structure. No flat sides from overcrowded nursery spacing.

06

Growth Habit: Natural, short internodes (dense growth) appropriate for the species.

07

Leader Integrity: For upright varieties, a single, dominant vertical leader is mandatory.

08

Pest Zero: Absence of boring holes, scale, or fungal cankers confirmed by in-person audit.

09

Root Cohesion: The root ball and trunk must move as a single unit without wiggle or looseness.

10

Species Purity: Verification that the specimen is true-to-type with no reverted foliage.

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