Sitka mountain ash

Photo: Walter Siegmund (talk) — CC BY-SA 3.0 · source

Survives zone 4 through 8

Harvest calendar

Best planted in early spring after your last frost, or in fall before the ground freezes, depending on your climate.

A Pacific Northwest and Alaska mountain native — adapted to cold, wet, subalpine-to-montane conditions and often found on rocky slopes near snowmelt. The fruit is mealy and astringent raw but sweetens after frost and can be cooked into pies and preserves, as with other rowans. ⚠ Not just astringent: raw fruit in this group contains parasorbic acid, which causes vomiting, stomach cramps and diarrhoea if you eat any quantity of it. Cooking, freezing, drying or a hard frost converts it to harmless sorbic acid — which is exactly why every traditional recipe cooks it and why the fruit is picked after the first frosts.

Hardiness

Zone 4–8

Habit

Shrub

Edible part

Fruit

Ripens

Summer–autumn

Mature size

Shrub 1–4 m, occasionally a small tree to 6 m; dwarfed to 0.3–0.6 m on exposed alpine sites

Light

Full sun to partial

Soil pH

6.0–7.0 (near-neutral)

Environment

Montane

Native range

Western North America along the Pacific coast and mountains — from Alaska and the Yukon south through British Columbia and the Cascade Range to northern California, and east to northern Idaho and northwestern Montana — occurring from mid-elevation coniferous forest openings up into subalpine slopes and meadows, roughly 900–2,000+ m.

Status

Wild

Years to fruit

2–4 yrs

Growth speed

Slow-growing, especially in youth — seedlings build a substantial root system before showing much top growth.

Spacing

250 cm (98 in) apart — about 6.3 m² (67 sq ft) per plant

Leaf shape

Pinnately compound, rowan-type leaves 10–20 cm long with 7–11 oblong-to-narrowly-elliptic leaflets, dull-to-shiny blue-green above and pale beneath, serrate above the middle.

Root system

A woody, multi-stemmed base with a fibrous root system — young plants establish substantial roots before much top growth appears.

Fruit description

Small pomes 6–12 mm across, ripening red-orange in September–October and persisting into late winter — raw fruit is described as poor quality (mealy and astringent) but sweetens after frost, and is used cooked in pies and preserves; the seeds, as in other Sorbus, may carry traces of hydrogen cyanide and are not eaten.

Propagation

By seed, which needs about 2 weeks warm followed by 14–16 weeks cold stratification before it will germinate; germination is slow and often erratic, and seedlings put most of their first-year energy into root establishment rather than top growth.

Pollination

Self-fertile

The edible parts listed above are a starting point, not a field guide. Identify a plant with certainty — ideally against a local authority — before eating any part of it, and read the full disclaimer. Spotted something wrong? Report it.