Hardy Oak Trials
oak.sinuatabrev
bullety4
The Southwest's Sky Islands host a wide array of hardy oaks.

I decided to cast about the Southwestern mountains for mast trees that can tolerate local conditions in Williams. The region starting at the western side of the Trans-Pecos Range in Texas and extending through Southern New Mexico all the way to the ranges of eastern Arizona, is the home of tens of species of high elevation oaks not seen on local plant palletes. All are accustomed to occasional arctic cold, monsoon rains, dry, windy springs, and limestone soils.

(Photo: Q. sinuata v. breviloba seedling. May, 2008)


oak.chrysolepsis
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The region's late frosts will select for oaks that delay bud-break until late May or June.

In March and April 2008 I planted a large sampling of Southwestern oaks into the warming ground.  Over 25 unique varieties were planted, including a Valley oak from Southern New Mexico, a Canby Oak and a Mexican White oak from northern Mexico, an evergreen Net-leaf oak, a Silver Leafed Oak, and a Chisos Red Oak, from 6000' elevation in Big Bend National Park.  I also trialed several "shin-oak" varieties from Texas, like Q. mohriana, Q. vasseyana, and Q. sinuata.

(Photo: Tender new growth of Canyon Live Oak, from NM. June, 2008)


oak.protection
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Field-planted oaks will require years of protection and irrigation to succeed here.

Kept safe within layers of wire, insulated by a cool, deep mulch and irrigated weekly, all the oaks have taken to their holes and put on a lot of top-growth. Three layers of wire protect each young tree. Working outwards, first comes the 1/2" galvanized mesh to repel voles and mice. Then a tall tube of chicken wire goes in the hole to repel gophers and cottontail rabbits. Then a three-foot high minimum column of 2x4", heavy gauge welded wire deters deer, jackrabbits, javelinas and the occasional, curious elk.

(Photo: 3-layer seedling-protection system. June, 2008)


oak.lacey
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Southwestern oaks produce tough foliage that resists heat, hail, wind and insects.

The Checkerspot caterpillar and leaf-cutter bee are tough on deciduous plants here. But only the larger, less woody-leaved oaks like Q. shummardii lost chunks of leaf to them. Some of the spur-throated grasshoppers nibbled at leaf-edges here and there, but they did little damage to the oaks. Q. texana, Q. glaucoides, and Q. gravesii grew the most this first year in the ground. Q. gravesii grew over three feet between May and September. Q. glaucoides and Q. texana put on 18 inches.

(Photo: Hardened new foliage of Lacey Oak, Q. glaucoides. August, 2008)


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