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Tree of the Month: December – Pecans

By December 19, 2018No Comments

Written by Collin McMichael, Education Coordinator

Mid to late fall in Central Texas and much of the South means it is time for fresh pecans. Regardless of whether someone says Peh-CAHN or PEE-can, most people can appreciate the state tree of Texas for its dignified beauty even if they disapprove of its healthy harvest.  Even though Texas may lay claim to the pecan as its very own, the pecan itself lays claim on Illinois with its species name, Carya illinoensis.  

The larger genus Carya is a group of trees known collectively as the hickories. Pecans can count pignuts, shagbarks, and mockernuts as their sister species, all of which are common trees found in the eastern portion of the country.  Hickories as a whole, however, have a more cosmopolitan distribution with a group even occurring in Asia. Hickories all belong to a larger family known as Juglandaceae, or the family of walnuts, which might be obvious if you are familiar with both walnut and pecan leaves and seeds.

Pecan leaves are notably pinnately compound.  Compound leaves are composed of multiple leaflets that all connect to a single midrib.  Compound leaves come in both palmate and pinnate styles, the former having leaflets arranged radially around a central point on the midrib and the latter having leaflets extending from the midrib sequentially as you move from petiole to leaf tip.  Pecans almost always have a terminal leaflet, unlike the potential look-a-like the western soapberry, and usually have around seven to nine leaflets per leaf.

Possibly a better character to use for identification than leaf shape, the pecan nut itself is usually evident on the tree or at least pieces are usually present below it if past the squirrel’s heyday.  These are oblong, brown nuts with darker striping usually present on the shell. They are often encased in thick, green fruits before fall that will stain your fingers black if you try to remove them. Once broken open, these nuts reveal a sweet flavored flesh present in two distinct lobes within the shell.  Be careful, however, as the shell contains enough tannins to convey a drying and puckering sensation if accidentally tasted.

The most commonly bought pecan in stores is probably the paper-shell pecans, a large group of pecan cultivars known for their larger nut and thinner shells like the Schley or Desirable pecan.  Other cultivars are known for superior flavor, nut shape, and disease resistance like the Elliot pecan. Cultivars of pecan are relatively new, at least for a tree, with major pecan cultivation not happening until the 1880s. Wild-type pecans generally have smaller, asymmetrical nuts and tougher shells, all attributes that humans tend to abhor, especially when offered a better option with a similar taste, although anecdotal evidence would point towards wild-type pecans having a more intense flavor.  Wildlife tends to ignore these differences, however, consuming both paper-shelled cultivars and wild-type pecans with gusto. In fact, one pecan tree can generally beget hundreds of baby pecans within a few years of producing nuts as not every squirrel-hidden-pecan gets found again come spring.  Each of these new baby trees tends to be rather different from the parent showing marked differences in disease resistance, nut size, and yield. They generally share a few traits with their mother tree, but being wind-pollinated means there is often little control over the male parentage.

When all pecans germinate, they immediately put out what is known as a taproot.  This is a large root that is oriented straight down despite differences between cultivars.  Unlike most commonly considered roots, this taproot is less of an organ for nutrient absorption and more of a holdfast for the tree.  This deep root allows the tree to remain anchored during inclement weather, even in their preferred waterlogged soils. During the winter the taproot also acts much like the root on a carrot, storing energy the plant will need come spring.  Nutrient absorption is mostly taken on by the lateral, finer roots. These can extend much farther than the branches of the tree, and pecans are known to experience root crowding in orchards before the canopy closes.

When planting a pecan tree, bare-root is often the best option. Trees are bare rooted during the dormant season, shipped where they need to go, and then planted in the local soil once they get there.  Unlike nursery trees which are potted in nursery soil, these bare-root trees are immediately confronted with the local soil conditions when growth happens meaning they are often better suited to their new homes after a year in the ground than potted trees.

Pecans grow rather quickly despite having hard, durable wood.  Usually, faster-growing trees have softer woods, but all hickories are known for the strength of handles and quality of furniture they produce.  Pecans usually reach maturity and start producing nuts around twelve years of age, however they are known to be alternate bearing trees. This means that after a heavy production year, pecans will often take a year off from producing nuts so as to regain vigor.  Reproduction can be taxing! But luckily, pecans are quite long-lived, regularly attaining the coveted 300-year mark for a tree.

If you’re looking for some truly breathtaking pecan specimens, Barkley Meadows Park by TX-130 and Hornsby Bend off of FM973 both have several notable examples.  Most old growth pecans are found to the east as they prefer the deeper, moister alluvial soils found by the creeks and streams. That being said, many 200-plus-year-old pecans can be found in drier habitats since the pecan is a known survivor.  Their deep root systems that can both find and store water in drought allow them to excel even in the Texas summers that most other plants can’t handle.

And if you’re looking for something really special, there are reports of “hiccons” in the area though they are extremely rare.  This is a cross between a pecan and another hickory, and they are known for having larger nuts with a pleasing taste. If you think you’ve found a hiccon, you should let us know!

Click here to read last month’s TOTM