There are more than 500 named pecan varieties, but just a handful are widely planted in the United States. For the homeowner or small scale commercial orchardist, the important differences between types of pecan trees include: pollination type; timing of flowering; size of the nut; shell thickness; tendency to bear in alternate years; age at first bearing; season of nut maturation; and resistance to the fungal disease, pecan scab.
Pecan Pollination: How Does it Work?
A pecan tree has both male flowers (pendant catkins), and female flowers (erect spikes), on the same tree. Type I (protandrous) pecans have male flowers that release their pollen before their female flowers are receptive to pollen shed. Type II (protogynous) pecans release their pollen after their female flowers were receptive.
Pecan Flowering Time
There is also variation in flowering time among varieties within each type. Both types must be present (within a few hundred feet) to get pollination and subsequent nut development, and the bloom periods must overlap. Experience has shown that three or more pecan varieties planted together provide the best pollination, and therefore the biggest nut crops. The suggested pollinators column in the table below takes into account both pollination type and bloom period. Pollination is done by the wind.
Size of Pecan Nuts and Shell Thickness
The nut size is measured by the number of nuts per pound. Large pecans have 55 or fewer nuts per pound; medium = 55-70 nuts/pound; and small = more than 70 nuts/pound.
We can get an idea of pecan shell thickness (= ease of shelling) by comparing the weight of the kernel with the weight of the whole nut. The higher the percent kernel, the thinner the shell. Thin shells are easier to get the husk off.
Alternate Bearing & Nut Maturity
Pecan trees are notorious for alternate bearing. Some varieties are prone to bigger yields one year and smaller crops the next, while others tend to produce good crops every year.
Bearing age is the early age at which nut production first begins. Normally, a grafted pecan cultivar, planted when about 4-6 feet tall, will start producing nuts in 6 or 7 years. More precocious varieties may start production in 4 or 5 years, and the least precocious, 8 to 10 years after planting. Seedlings and wild pecans (they occur naturally in the bottomlands of the Mississippi and other rivers westward into East Texas and Mexico) can take 12 to 15 years to begin production. Note that the most precocious varieties may start production as young trees but they often have an alternate bearing in later years. More information about this on our Pecan Grow Guide.
Nut maturity is the relative time of year that the pecans become ripe. The actual calendar dates for early, mid-, and late season pecans vary with climate zone, of course. In much of USDA Zone 8, for example, early season pecans typically ripen from mid September through the end of September; mid-season cultivars from early October through mid October; and late season varieties after mid October.
There are many diseases and pests that attack pecan trees and nuts. Disease and pest susceptibility vary year-to-year due to variations in weather, local conditions, the health of the trees, and, of course, the pecan variety. Therefore, the more different varieties you plant, the better are your chances of getting a successful crop every year. Pecan scab is among the worst of pecan diseases. It is most destructive where humidity is highest. If your planting site is surrounded by wetlands, avoid varieties with poor scab resistance. There are recommended varieties with disease resistance notated below.
The table that follows provides important characteristics of several common papershell pecan tree varieties, most of which are offered by Perfect Plants Nursery.
Pecan Tree Identification Chart
|Amling||I||Sumner, Stuart, Elliott, Zinner||62||55||intermediate||4-5||mid||excellent|
|Caddo||I||Sumner, Stuart, Elliott, Kanza||67||54||no||5-6||mid||fair|
|Cape Fear||I||Sumner, Stuart, Elliott, Kanza||55||51||no||4-7||late||good|
|Desirable||I||Sumner, Stuart, Elliott, Kanza||48||51||no||6-7||mid-late||poor|
|Mandan||I||Kanza, Forkert. Stuart, Zinner||49||57||no||5-8||early||good|
|Oconee||I||Cape Fear, Stuart||48||53||no||6-7||mid||fair|
|Pawnee||I||Forkert, Kiowa, Sumner, Stuart||56||60||intermediate||6-8||early||poor|
|Candy||II||Cape Fear, Creek, Desirable||70||45||yes||4-5||early||good|
|Curtis||II||Cape Fear, Creek, Desirable||89||53||intermediate||6-8||late||excellent|
|Elliott||II||Caddo, Desirable, Oconee, Pawnee||77||51||yes||7-10||mid||excellent|
|Forkert||II||Cape Fear, Elliott, Kanza, Sumner||53||58||intermediate||5-8||mid-late||fair|
|Kanza||II||Caddo, Desirable, Oconee, Pawnee||74||52||yes||7-8||early||excellent|
|Kiowa||II||Caddo, Desirable, Oconee, Pawnee||48||53||intermediate||5-6||late||fair|
|Stuart||II||Cape Fear, Desirable, Elliott||55||46||intermediate||8-10||mid||fair|
|Sumner||II||Cape Fear, Desirable, Oconee||56||49||intermediate||7-9||late||good|
|Zinner||II||Caddo, Creek, Cape Fear, Desirable||44||54||no||6-7||mid-late||excellent|
We hope this information was useful for you. Pecans are truly one of a kind and one of our favorites here on the nursery being in the South. Not only do they provide delicious nuts that are a health food, they are an attractive tree for any landscape. Happy Planting!!
What kind of pecan trees are you growing? Let us know in the comments!