Pecan

Sun

Full sun; allow the crown open exposure for good flowering and nut development.

Water

Moderate to high; water deeply during dry weather, particularly while young and during nut development.

Soil

Deep, fertile, well-drained soil that retains moisture, ideally slightly acidic to neutral. Avoid shallow soil, permanent waterlogging and strongly alkaline ground.

Height

60-100 ft (18-30 m)

Spread

40-75 ft (12-23 m)

Flowers

Spring; yellow-green male catkins and small, inconspicuous green female flowers on the same tree.

Foliage

Large, alternate leaves divided into usually 9-17 narrow, toothed leaflets, often curved at the tips; green in summer and yellow to yellow-brown in autumn.

Growth

Moderate to fast in warm climates with adequate moisture.

Care needed

High

• Heat tolerant
• Wildlife
• Edible

Northern hemisphere months. In Australia, shift them by six.

Difficulty

Hard

Toughness

Fairly tough

Pick your zone, country, light and whether you have pets.

1. Planting day

   9 ft (2.9 m)

2. After 1 year

   14 ft (4.2 m)

3. After 2 years

   18 ft (5.5 m)

4. After 3 years

   22 ft (6.8 m)

5. After 5 years

   31 ft (9.5 m)

About 16 years to full size.

From a typical nursery size, at an average rate for this kind of plant. A rule of thumb, not a forecast.

Cats and dogs

Safe

Native to

the US

Growth rate

Fast

• Choose a grafted cultivar suited to your local season length; northern areas need early-ripening selections.
• For dependable crops, plant two compatible cultivars with overlapping pollen release and female flower receptivity, usually one Type I and one Type II.
• Water young trees deeply through dry spells, and prevent drought stress while established trees are filling nuts.
• Spread organic mulch over the root area, keeping it clear of the trunk; limit grass competition around young trees.
• Use soil tests to guide feeding. Have suspected zinc deficiency confirmed before treating, especially on alkaline soils.
• Allow room for the mature crown and keep the tree away from buildings, overhead wires and heavily used paved areas.

Pruning. Train young trees in late winter while dormant to a strong central leader with well-spaced branches, removing competing leaders and narrow forks. Prune mature trees sparingly to remove dead, damaged or crossing wood; use a qualified arborist for large limbs and never top the tree.

Harvest nuts when the green husks split and brown-shelled nuts fall: usually September–November in the US, October–November where they ripen in the UK or southern Canada, and March–May in Australia. Collect fallen nuts promptly, remove any remaining husks, and dry them in a single layer somewhere airy and sheltered until the kernels snap rather than bend.

Winter

Choose locally suitable grafted cultivars and check that their pollination periods overlap.

Late winter

Plant dormant trees where soil is workable, and carry out light structural pruning before budbreak.

Spring

Refresh mulch, check irrigation and apply nutrients only as indicated by soil tests or local recommendations.

Late spring

Inspect developing leaves and nuts for scab and aphids, especially during humid weather.

Summer

Maintain deep watering during dry periods, particularly as nuts enlarge and kernels fill.

Autumn

Collect ripe nuts promptly as the husks split and nuts fall; dry them in a sheltered, well-ventilated place before storage.

Late autumn

Remove fallen husks and spoiled nuts to reduce pest carryover and keep mouldy material away from pets.

• Use as a broad shade tree in a large lawn, well away from patios where falling nuts and twigs would be troublesome.
• Plant compatible cultivars in a spacious home orchard with access for watering and harvesting.
• Use as an upper-canopy tree in a large food forest, with smaller fruiting trees beyond its densest shade.
• Combine with native grasses and flowering perennials around the sunny edge of the canopy for a parkland effect.

Garden styles it suits: Backyard orchard, Edible landscape, Homestead, Grand estate, Southern and Food forest.

Plant it with: Eastern redbud, Pawpaw, Serviceberry, Switchgrass, Purple coneflower and Black-eyed Susan.

Wildlife: Nuts feed squirrels, other small mammals and some birds. The canopy supports insects and provides shelter and nesting sites; flowers are wind-pollinated rather than a major nectar source.

• Pecan scab causes dark lesions on leaves and husks and can ruin crops in humid regions. Choose locally proven resistant cultivars, maintain airflow and seek local advice before using a fungicide programme.
• Aphids cause sticky honeydew, sooty mould or yellow spotting. Encourage beneficial insects, avoid excess nitrogen and treat only damaging infestations with a locally approved product.
• Pecan weevils can leave empty or grub-infested nuts where this pest occurs. Collect and destroy damaged nuts and obtain local advice on monitoring and treatment timing.
• Poor or unfilled crops result from inadequate pollination, short cool summers or drought during kernel filling. Match early-ripening cultivars to your climate, provide compatible pollen and maintain summer moisture.

Sound kernels are edible for people, though pecans can cause severe reactions in people with tree-nut allergies. Fresh pecan foliage and wood are not known to be seriously toxic to cats, dogs or horses. Do not offer nuts or husks to pets or livestock: shells can cause choking or intestinal blockage, and mouldy nuts can contain toxins that cause tremors or seizures, particularly in dogs.

• Bitternut hickory (Carya cordiformis)

  Has conspicuous sulphur-yellow winter buds, usually 7-9 leaflets and small, bitter nuts; pecan has longer nuts and usually more leaflets.

• Black walnut (Juglans nigra)

  Its nuts sit inside thick, rounded green husks that do not split neatly into four sections. Pecan nuts are elongated, with husks that split along four seams.

• Shagbark hickory (Carya ovata)

  Mature bark peels in long, loose strips, and leaves usually have five leaflets. Pecan bark is ridged rather than conspicuously shaggy, and its leaves have many more leaflets.

Carya comes from the Greek word for a nut tree, illinoinensis refers to Illinois, and pecan derives from an Algonquian word for a nut requiring a stone to crack.

Propagation. Sow fresh nuts after cold, moist stratification to raise seedlings, but expect variable nuts and a long wait for bearing. Named cultivars must be budded or grafted onto suitable rootstocks; buying a grafted tree is the practical choice for predictable harvests.

Accepted botanical name

Carya illinoinensis

In the US and Canada

Native in the lower 48 states.

Native range

Arkansas, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Mexico Central, Mexico Gulf, Mexico Northeast, Mexico Southwest and Mississippi.

Measured

Average height 1750 cm.

Sources: GBIF (CC BY 4.0), USDA PLANTS and Trefle (CC BY 4.0). The care and design notes are LandscapeGPT's own.