At a glance
| Botanical name | Carya illinoinensis |
|---|---|
| Family | Juglandaceae (walnut and hickory family) |
| Type | Large deciduous nut tree |
| USDA zones | 5–9 per NC State; nut crops drop where springs are late and summers cool |
| Mature size | Commonly 70–100 ft tall (up to 130 ft) with a 40–75 ft spread |
| Light | Full sun |
| Soil | Deep, well-drained; native to river bottomlands |
| Pollination | Wind; plant at least one Type I and one Type II cultivar, ideally three cultivars |
| Harvest | Fall, when husks split and nuts drop |
| Native range | Central and east-central US to Mexico |
| Years to first crop | Few nuts during a 5–7 year establishment period; seedlings take most of a decade |
What a pecan tree is
The pecan is the largest of the hickories and, per the Missouri Department of Conservation, one of the most important cultivated nuts of North America. It is native from the central and east-central US to Mexico, where it grows naturally in rich, moist bottomland soils, and it is widely planted beyond that range. Per MDC, the nuts feed wildlife including larger birds, squirrels, opossums, raccoons and deer.
Because a pecan becomes a very large, long-lived tree, siting decisions made at planting last for generations.
How to identify a pecan tree
- Leaves: alternate and pinnately compound, often more than a foot long (MDC gives 9–20 inches), with 9–17 lance-shaped, toothed leaflets that are often curved.
- Bark: grayish brown, with long, flat, loose ridges on older trees.
- Flowers: long, drooping male catkins in spring; small, inconspicuous female flowers at the tips of new shoots.
- Nuts: oblong nuts 1–3 inches long, often with dark markings on the shell, inside a thin husk with four ridges. The husk splits into four sections in fall to release the nut.
- Habit: tall, straight trunk and a broad, spreading crown in the open.
Pecan look-alikes
| Tree | How it differs |
|---|---|
| Other hickories (bitternut, shagbark) | Smaller trees with different leaflet counts and nuts; MDC lists several as pecan look-alikes. See how to identify hickory trees. |
| Black walnut | Per NC State, pecan has fewer and longer leaflets than black walnut; walnut bears a round nut in a husk that does not split into four sections. See how to identify walnut trees. |
Climate: where pecans produce
Pecan trees survive farther north than they reliably produce nuts. Per NC State, nut production can be reduced in the northern part of the range, especially when spring is late and summer is cool. Clemson does not recommend pecans for South Carolina's mountains because late freezes reduce yields.
- Humid Southeast: scab disease drives cultivar choice.
- Arid West: irrigation is essential; Clemson notes commercial growers have irrigated since the 1970s to protect nut quality.
- Northern edge of the range: Texas A&M advises early-maturing cultivars where fall freezes come early, and expect lighter crops in cool years.
Your state Extension service keeps the list of cultivars proven locally; start there rather than with a mail-order catalog.
Pollination: Type I and Type II pecans
Pecans are wind-pollinated and carry male catkins and female flowers on the same tree, but within a cultivar pollen shed usually does not overlap with the period when the female flowers are receptive. This is called dichogamy, and it is why a lone pecan often sets few nuts.
| Type | What happens | Examples |
|---|---|---|
| Type I (protandrous) | Releases pollen before its own female flowers are receptive | 'Desirable', 'Pawnee', 'Cape Fear', 'Caddo' |
| Type II (protogynous) | Female flowers are receptive before its own pollen sheds | 'Elliott', 'Kanza', 'Stuart', 'Sumner' |
Types per Clemson HGIC and Texas A&M AgriLife. Plant at least one cultivar of each type; Clemson advises planting within 200 feet of one another and at least three cultivars for maximum pollination, and NC State likewise recommends three cultivars with at least one of each type. Where wild or planted pecans are common nearby, pollination is not normally a problem, per Clemson.
Choosing pecan cultivars
In the humid Southeast, pecan scab is the factor that decides success. Per Clemson HGIC, most homeowners lack the special equipment needed to spray a whole pecan canopy once the tree gets tall, so backyard trees there should be scab-resistant cultivars. Clemson's landscape list rates 'Cape Fear', 'Creek', 'Elliott', 'Gloria Grande', 'Kanza', 'Stuart' and 'Sumner' as scab resistant. UGA's pecan breeding program ranks 'Elliott' as the long-standing standard for excellent resistance and notes 'Kanza' has been outstanding so far, while rating 'Desirable' low; it also warns that 'Cape Fear' and 'Stuart' have become fairly susceptible in Georgia orchards as scab races adapt.
| Your situation | Priority |
|---|---|
| Humid Southeast backyard | Scab resistance first, then pair Type I with Type II |
| Arid Southwest | Irrigation plan and cultivars your state lists for the desert |
| Northern edge (zones 5–6) | Early-maturing, cold-tolerant cultivars that fill before frost |
Trees grown from a planted pecan nut won't match the parent, and their nut quality is unpredictable. Buy grafted cultivars.
How to plant a pecan tree
- Site: full sun in well-drained soil; Clemson rules out poorly drained soil, hardpans, stiff clays and thin sands with a high water table. Keep the tree well away from buildings and overhead power lines, and space trees at least 60–80 feet apart.
- Timing: plant bare-root trees any time during dormancy, with late fall and early winter best; Clemson rates container-grown trees superior and best planted early in the dormant season. A 4–5 ft nursery tree is the best size.
- Protect the taproot: NC State notes the deep taproot makes pecans difficult to transplant. Clemson digs a hole at least 24 inches wide and 2½–3 feet deep, trims the taproot only if needed to fit, and never twists lateral roots.
- Depth: set the tree at the depth it grew in the nursery, fill and water in stages to settle the soil, and build a basin that holds 10–15 gallons. Don't put fertilizer in the planting hole.
- Prune the top: Clemson HGIC says to remove one-half of the top of the new tree to encourage vigorous growth and rapid establishment.
- Mulch with 2–3 inches of pine straw, leaves or old sawdust, kept off the trunk, to conserve moisture and reduce grass and weed competition.
More on handling dormant stock is in how to plant bare-root trees.
Pecan tree care: water, fertilizer and zinc
Water
Per Clemson HGIC, watering is the main aftercare chore for the first two or three years: apply 10–15 gallons a week from rain or irrigation. Bearing trees should be watered weekly, especially during heat and drought in August and September. Per Clemson's Reasons for Poor-Quality Pecans, nuts fail to fill mainly because of insect and disease damage to leaves, and drought late in the season also causes poor filling and premature nut drop.
Fertilizer
Base fertilizer on a soil test, and for bearing trees a leaf tissue analysis as well. Clemson HGIC's planting and fertilization fact sheet gives rates by trunk diameter, targets 2–4 feet of terminal growth a year on young trees and about 6 inches on bearing trees, and recommends a soil pH of 6.0–6.5. Its Reasons for Poor-Quality Pecans warns that excessive fertilizer promotes disease and insect problems.
Zinc
Per Clemson HGIC, zinc nutrition is especially important for pecans. Deficiency causes rosette: bronzed, mottled leaves, small yellowish leaves bunched at the tips of short, thin twigs, dead twigs in the top of the tree, early leaf drop and abnormally small nuts; an early sign is a wavy margin on the leaflets. Clemson suggests 1 pound of zinc sulfate per tree for each of the first three years after planting, but for bearing trees advises zinc only when a soil or leaf test shows a deficiency, because routine annual zinc can build up to excess. For telling zinc from other deficiencies, see nutrient deficiencies by leaf symptom.
Pruning
Mature pecans need little pruning beyond removing dead or broken wood. Clemson recommends removing limbs that touch the ground, which improves air movement and reduces the leaf wetness scab needs, and removing limbs below 6 feet where squirrels are a problem. Large-limb work on a big tree is a job for an arborist.
How long until a pecan tree produces?
Pecans are slow to start. Per Texas A&M AgriLife, trees bear very few pecans during an establishment phase of about 5–7 years, and Clemson lists precocity (the age a tree begins to bear) as one of the factors that differ by cultivar. Per NC State, a tree grown from seed takes the better part of a decade to produce a significant crop.
Even mature trees tend toward alternate bearing, a heavy crop one year and a light one the next. Per Clemson, a lack of water and inadequate fertilization both worsen the swing, so irrigation and test-based feeding reduce it.
Harvesting pecans
Pecans are ready in fall when the husks split into four sections and the nuts begin to fall. Per Clemson HGIC, harvest as soon as the nuts mature: letting them lie on wet ground is one of the quickest ways to lose quality, and squirrels are often serious pests. Store harvested nuts in a clean, dry place.
Pests and diseases
Per Clemson HGIC's pecan fact sheets, the most common causes of poor nuts and damaged trees are:
- Pecan scab: the most prevalent pecan disease; small olive-green to black spots on leaves and nut shucks that enlarge, blacken and look sunken, and early nut infections cut yield and quality. Resistant cultivars are the practical home defense, and raking up leaves and shucks in winter reduces carry-over. See Clemson's Pecan Diseases.
- Pecan weevil: pick up prematurely dropped and infested nuts at least twice a week.
- Hickory shuckworm: clean up old shucks and debris weekly.
- Aphids and mites: Clemson suggests insecticidal soap sprayed as high into the tree as possible.
- Twig girdlers: pick up and discard girdled twigs and limbs.
- Fall webworm: silk webs at branch tips; Clemson suggests Bt as soon as webbing appears. See tent caterpillars vs fall webworm.
Common mistakes
| Mistake | Why it matters | Do this instead |
|---|---|---|
| Planting a single pecan, or two of the same type | Mismatched pollen and flower timing gives poor nut set | Plant at least one Type I and one Type II cultivar, ideally three cultivars |
| Planting a scab-susceptible cultivar in the humid Southeast | Most homeowners lack equipment to spray a tall tree's whole canopy | Choose scab-resistant cultivars |
| Planting close to a house or septic field | The tree becomes huge and long-lived | Site it well clear of structures and lines |
| Skipping water in late summer | Late-season drought causes poorly filled nuts and nut drop | Water weekly, especially through August and September |
| Ignoring rosette on young trees | Zinc deficiency stunts growth and nut set | Give young trees zinc sulfate; test soil or leaves before adding zinc to bearing trees |
Frequently asked
How long does it take a pecan tree to produce nuts?
Per Texas A&M AgriLife, grafted trees bear very few nuts during an establishment phase of about 5 to 7 years, and cultivars differ in how early they start. Trees grown from seed take the better part of a decade to produce a significant crop, per NC State, and their nut quality is unpredictable.
What does a pecan tree look like?
A pecan is a tall tree with a broad, rounded crown in the open and long compound leaves made of 9 to 17 lance-shaped, often curved leaflets. In fall it carries oblong nuts in thin, four-ridged husks that split into four sections.
Do you need two pecan trees to get nuts?
For good crops, yes. Most cultivars shed pollen and receive it at different times, so pair a Type I cultivar with a Type II cultivar; Clemson and NC State suggest at least three cultivars, planted within about 200 feet of one another. Where wild or planted pecans are common nearby, pollination is usually not a problem.
Can you grow a pecan tree from a pecan?
Yes, a pecan nut can sprout, but the tree will not match its parent, and NC State notes it takes the better part of a decade to produce a significant crop. Named cultivars are grafted so the nuts are predictable.
How big does a pecan tree get?
Per NC State, pecans usually grow 70 to 100 feet tall, occasionally up to 130 feet, with a spread of 40 to 75 feet. Clemson advises spacing landscape trees 60 to 80 feet apart and well away from buildings and power lines.
How much water does a pecan tree need?
Clemson HGIC recommends 10 to 15 gallons a week for young trees during their first two or three years. Bearing trees should be watered weekly, especially during heat and drought in August and September, since late-season drought causes poorly filled nuts.
How long do pecan trees live?
Pecans are large, long-lived trees, which is why Clemson advises spacing landscape trees far enough apart, 60 to 80 feet, that they will never need to be removed. Site selection and spacing matter more at planting than for almost any other fruit or nut tree.
Sources
- Pecan Planting & Fertilization, Clemson Cooperative Extension HGIC
- Reasons for Poor-Quality Pecans, Clemson Cooperative Extension HGIC
- Pecan Diseases, Clemson Cooperative Extension HGIC
- Review of Scab Resistant Cultivars, University of Georgia Pecan Breeding Program
- Carya illinoinensis, NC State Extension Gardener Plant Toolbox
- Pecan, Missouri Department of Conservation Field Guide
- Improved pecan cultivars, Texas A&M AgriLife Extension (Aggie Horticulture)