This species is undeniably one
of the toughest oaks, endemic to the dry limestone of the Texas Hill
Country, Kerr, Gillespie, Medina and Bandera counties, it thrives in
places where no other oak does, from the top of the canyon escarpments to
the bottom, thriving amongst the rocks with the poorest of soils. It is
a smaller oak than most, with a round top and shrub like appearance. Dark,
blue green leaves are its distinguishing features with very small acorns.
Relished by turkeys and feral hogs this acorn never gets a chance to grow
into a tree. It is definitely a good landscape potential in dry rocky
areas, but not with deep fertilized soils under irrigation, as it is not
tolerant of a lot of water, it likes highly alkaline, well drained rockey
soils. Plant this one where you can see it on a hillside.
Lacey oak is a beautiful small to
medium size deciduous tree with a minor identity problem, being known
alternately as Quercus laceyi or Quercus glaucoides. Most folks simply
call it lacey oak, but other common names it has worn over time include
blue oak, canyon oak, encino robie, mountain oak, smoky oak, and rock oak.
Most of these common names refer to the tough conditions in central and
south Texas where this species resides or are related to its handsome
blue-green
foliage.
Regardless
of the name, this plant has much to offer as a landscape plant in its native
Texas. Leaves expand as a soft pink color, turning a handsome blue-green as
they mature lending the plant an intriguing smoky air. The foliage is seldom
bothered by insects or disease. Fall color varies from brown to yellow.
Growth habit will vary with local environmental conditions, with the
ultimate size ranging in most cultivated landscapes from 30' to 35' in
height and spread. One of the best attributes of lacey oak is it's
picturesque irregularly rounded crown. With this crown placed atop a
stoutish trunk baring platy gray bark it makes a handsome addition to Texas
landscapes, resembling a miniature white oak, but of tougher constitution. This
lady is Texas Tough!
Lacey oak is
highly tolerant of heat, drought, and high pH soils once established. Full
sun to light afternoon shade with morning sun are the best exposures. Lacey
oak will survive on well drained clay soils, but it grows best on
well drained limestone soils. Although lacey oak can be grown in east Texas,
it is best adapted to the hill country and cultivated settings in west
Texas. Cold tolerance has not been fully documented for lacey oak, but based
on regional plantings it should be suitable for use in USDA zones 7 (perhaps
protected spots in 6b) through 9.
Lacey oak is a Texas SuperstarTM,
but even superstars have limits. Limitations for lacey oak include an
intolerance to poorly drained soils, a moderate growth rate, and a tendency
to need some initial minor pruning to maintain a strong central leader.
Growth and landscape appeal in high rainfall areas will be enhanced if the
trees are planted on raised beds or berms.
Landscape utilization of lacey oak might
include placement as a specimen plant, small to medium size lawn or shade
tree, or site it to shade a patio. This species would be a natural in native
Texas landscapes and naturalized plantings, where the acorns can serve as a
wildlife attractant. Xeriscapes or low water use landscapes are perfect
conditions for growing lacey oak. For a bit of the unusual, try growing
lacey oak as a specimen in large containers to accent courtyards or
entryways to large buildings. The picturesque growth habit of this species
would be accentuated if it were used as a bonsai plant.
Lacey oak deserves frequent consideration
when discussing smaller shade trees that will stay in scale with residential
landscapes. This beautiful tree will add a touch of the Texas hill country
to your urban landscape.
The Lacey oak is of the white oak family
which is somewhat more resistant to oak wilt. NOT
SO!
Draft press release submitted by Michael
A. Arnold, 7/25/02
Photo credit: Texas A & M Experimental Stn.
Now The Bad News
Lacey oaks, believed to be resistant to
oak wilt are highly susceptible to oak wilt and, like live oak trees, they
grow in groves or Motts and the roots are intergrafted. Once oak wilt
affects a grove or Mott of these trees, there is no stopping the disease,
Fungicide treatment is useless to arrest the disease in an infected tree and
it is very chancey to protect adjacent healthy trees.
Our experience with the Lacey Oak and oak
wilt is very limited and the resullts have been always disasterous. In
fifteen years, I have observed approximately a dozen incidents of Lacey
oaks being exposed and succumbed to the devastation of oak wilt. It is
totally futile to make any attempt to inject or isolate an infected tree
from other near by trees. Most arborist have very limited or no experience
with lacey oaks infected with oak wilt. If they say. they can save your
lacey oaks, they are just wasting your money. They grow in very rocky areas,
the canyon walls are steep, and it is almost impossible to isolate by
trenching. Also, they are a very drought tolerant trees and the disease
moves very quickly from one tree to the next.
These photos illustrate the effects and
varying degrees of progression of infected trees amongst healthy trees. The
healthy ones may succumb to the ravages of oak wilt even when treated with
the fungicide. We do not have a lot of experience in the treatment or the
results of treatment with lacey oaks. Any trees we have treated in early
stages of infection have been unsuccessful. Trees adjacent to the infected
centers are at high risk even when treated. With lacey oaks, once
the infection starts, it is unstoppable!
