Grand Fir

Grand fir (Abies grandis, Pinaceae) is a moderate-growing native conifer ranging from southern British Columbia along the coast to California and inland to central Idaho, the largest Abies species, reaching up to 200 feet tall with a spread of 26 feet. It develops a conical crown with slightly drooping branches. Flat needles are arranged almost at right angles in two rows, alternating short and long (1.5 to 6 centimeters), shiny dark green above and silvery-white beneath, emitting an orange fragrance when crushed. Upright cylindrical brown cones are 5 to 10 centimeters long.

Grand fir grows in part shade on adaptable soils (pH 5.0 to 7.0) with moderate water needs and medium drought tolerance, hardy in Zones 3b to 8b. It is fire resistant with a deep, wide-spreading root system and reaches about 25 feet at 20 years. Disease pressure is significant, with 17 documented associations including Heterobasidion root disease, needle cast, and Phytophthora root rot. Pest associations include balsam woolly adelgid, spruce budworm, and spruce spider mite. Cultivars include 'Johnsonii' (dwarf, 3 feet, narrow form), 'Aurea' (yellow new foliage), and 'Compacta' (small round ball).

Grand fir is the native fir that actually works in the Puget Sound lowlands. Unlike noble fir, which is a montane species that struggles below 2,000 feet, grand fir naturally occurs in low-elevation floodplains and valley bottoms. It tolerates the glacial till and alluvial soils typical of our lowlands, handles moderate shade, and establishes faster than most people expect. The tree gets large (200 feet in forest conditions) so it needs space. Broom rust and needle necrosis are the main disease concerns, cosmetic in most years. Balsam woolly adelgid is present in the region and can stress grand fir, but healthy, well-watered trees resist it. The crushed foliage smells strongly of citrus, which is a reliable identification feature. For a native evergreen that handles lowland conditions without the moisture demands of western hemlock, grand fir is the better choice.

— Chris Welch, ISA Certified Arborist