pecan

Photo: Bruce Marlin — CC BY 3.0 · source

Survives zone 5 through 9

Harvest calendar

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

The most cultivated and commercially important hickory by far — thin-shelled, sweet, oily kernels that need little processing compared with the thicker-shelled wild hickories, and the basis of a major US commercial nut crop across the South. Needs a long, hot growing season to ripen its nuts well and struggles in cool-summer climates outside its native and adapted range.

Hardiness

Zone 5–9

Habit

Tree

Edible part

Nut

Ripens

Oct

Mature size

Very large tree 20–40 m, occasionally to 44 m, spreading 12–23 m — not containerable

Light

Full sun

Soil pH

6.0–7.5 (near-neutral; lime-tolerant)

Environment

Riparian

Native range

The Mississippi valley and the rivers of the south-central United States and northern Mexico — Iowa and Illinois south to Texas, Louisiana and Oaxaca — on deep alluvial bottomland that floods and drains. That riverine origin is why pecans want deep soil and a long, hot summer.

Status

Cultivated

Years to fruit

6–10 yrs

Growth speed

Medium growth rate for the genus — faster than the other wild hickories, though still slower than many other large nut trees; orchard trees can begin bearing 3–4 years after grafting.

Spacing

1200 cm (472 in) apart — about 144 m² (1550 sq ft) per plant

Leaf shape

Pinnately compound, with 9–17 (occasionally up to 23) lance-shaped, often slightly sickle-curved (falcate) leaflets with finely serrate margins — the highest leaflet count of any North American native tree.

Root system

A deep taproot forms early, similar to other hickories, which is why pecan nursery stock is planted young and root-pruned/managed carefully in production.

Fruit description

An elongated, thin-shelled nut up to about 4 cm long borne in clusters of 3–11 inside a husk that splits into four sections at maturity; the kernel is famously sweet, oily and rich, the best-eating and thinnest-shelled nut of the genus and the only one grown as a major commercial food crop.

Propagation

Propagated from seed for rootstock — seed needs cold stratification and, because of the deep taproot, is best sown directly where it will grow or raised in deep pots and moved to a permanent site in its first summer. Named cultivars are always grafted, most commonly by whip grafting, four-flap (banana) grafting, or bark grafting onto seedling rootstock in spring, or by patch budding onto slightly older rootstock in mid-to-late summer when the bark is slipping; pecan grafting is considered one of the more demanding nut-tree grafts to perform successfully and success rates vary considerably by cultivar and technique.

Pollination

⚠ DICHOGAMOUS — needs Type I and Type II cultivars together

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.