How to grow pecan
Overview
Pecan (Carya illinoinensis) is a large, deciduous nut tree from the Juglandaceae family, grown for its rich, oily nuts. It requires warm summers, deep fertile soil, and ample space to mature. A second tree of a different variety is needed for reliable pollination.
Varieties
- Wichita — A heavy-bearing, early-season variety suited to warmer climates; needs a pollinator like 'Western'.
- Western Schley — A reliable, high-quality nut with good kernel fill; popular in commercial orchards across temperate and subtropical zones.
- Mahan — Very large nuts but thin shells; best in subtropical areas with long, hot summers.
- Caddo — A compact, early-maturing tree with good disease resistance; ideal for smaller gardens.
Soil Preparation
Pecan prefers deep, well-drained loam with a pH of 6.0–7.0. If soil is heavy clay, plant on a mound and add gypsum. Dig in 5kg of well-rotted manure or compost per square metre before planting. Avoid waterlogged sites.
Growing Guide
Plant pecan in full sun with at least 8m of space from other trees and structures. Dig a deep hole (60cm) and backfill with well-rotted compost. Water deeply every 7–10 days in the first year. Mulch with wood chips, keeping it 10cm clear of the trunk. Stake young trees for the first two seasons.
Sowing
Pecan is usually grown from grafted trees for reliable nut quality and earlier cropping. Seed-grown trees take 10–15 years to bear and may not produce true to type. Sow fresh nuts 5cm deep in autumn, but expect variable results.
Care
Feed pecan with a balanced fertiliser (e.g., 10-10-10) in early spring and again in early summer, plus a zinc foliar spray to prevent rosette. Prune in late winter to establish a central leader and remove crossing branches. Deep mulch (10–15cm) over the root zone helps retain moisture and suppress weeds.
Companion Planting
Underplant with clover, comfrey, or native groundcovers to build soil and attract pollinators. Avoid planting near black walnut (juglone) or in lawns that compete for water. Keep grass away from the trunk to reduce borer risk.
Common Pests & Risks
Pecan aphids cause sticky honeydew and sooty mould; spray with horticultural oil in early spring. Borers (especially in stressed trees) can be prevented by keeping the trunk clean and avoiding wounding. Nut-feeding bugs like stink bugs and leaf-footed bugs may damage developing nuts; control with netting or pyrethrum if severe.
Harvesting
Harvest pecans when the outer husk splits and nuts fall naturally, usually from late autumn. Gather promptly to avoid mould. Dry in a single layer in a warm, airy spot for 2–3 weeks before storing in a cool, dry place.
In the Kitchen
Pecans are best eaten raw, roasted, or used in baking (pies, biscuits, and salads). Store shelled nuts in an airtight container in the fridge for up to 6 months, or freeze for longer. Toast lightly before adding to dishes to enhance flavour.
Troubleshooting
Yellow leaves with green veins: zinc deficiency (common in alkaline soils); apply zinc foliar spray. Brown leaf edges: salt burn from over-fertilising or dry conditions; flush soil and reduce fertiliser. Poor nut fill: lack of pollination or insufficient summer heat; plant a second variety. Small, shrivelled nuts: water stress during kernel fill; maintain even moisture from January to March. Black spots on leaves: pecan scab; prune for airflow and apply copper spray in wet seasons.