Klamath plum

Photo: Stan Shebs — CC BY-SA 3.0 · source

Survives zone 6 through 9

Harvest calendar

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

Considered one of the best-flavoured wild fruits of the Pacific Northwest — pleasantly acid, with the best individual trees carrying a distinctive slight astringency prized for culinary use. Also called Pacific plum or Sierra plum. ⚠ Kernels/pits cyanogenic.

Hardiness

Zone 6–9

Habit

Tree

Edible part

Fruit

Ripens

Aug–Sept

Mature size

To 7.5 m (25 ft)

Light

Full sun

Soil pH

5.5–7.5 (mildly acid to mildly alkaline) — sandy or loamy, not clay

Environment

Temperate

Native range

California and southern Oregon — coastal forest, Sierra Nevada and Cascades, 100–1,900 m elevation.

Status

Wild

Years to fruit

3–5 yrs

Growth speed

Medium

Spacing

400 cm (157 in) apart — about 16 m² (172 sq ft) per plant

Leaf shape

Alternate, lance-shaped to obovate, finely and sharply toothed, with a pair of small glands (extrafloral nectaries) on the leaf stalk near the blade — a Prunus signature worth learning, since it separates the genus from most look-alikes.

Root system

Shallow and strongly suckering, throwing root shoots that build a thicket over time — the natural habit of the American plums. Useful for stabilising a bank, a nuisance in a border, and the reason a single planted tree becomes a clump. Suckers are also the easiest way to propagate it.

Fruit description

Up to 3 cm, one large seed, pleasantly acid

Propagation

Seed (2–3 months cold stratification, sow fresh), cuttings in mid-to-late summer, or spring layering.

Pollination

Hermaphrodite, insect-pollinated.

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.