Download Notes from SFA Gardens A Mexico Mountain Sugar Maple

Notes from SFA Gardens
A Mexico Mountain Sugar Maple - Acer skutchii
This is a somewhat
extended version of some notes
on a plant we‟ve been touting
for some time. The cloud forest
sugar maple, Acer saccharum
ssp. skutchii, occurs as five
disjunct populations, with four in
Mexico and one in Guatemala.
First described in Guatemala in
1936, this species is the
southernmost sugar maple, a
rare relic from the Miocene era,
probably separated from those
in North America in the
Pleistocene. While there‟s very
little information available, an
internet search reveals an
excellent thesis on Acer skutchii
by Yalma Luisa VargasRodriguez who graduated from
Louisiana State University in
1995. For those readers
interested in the ecology and
natural range of the species, this
is the ultimate source of
information. You can access
that thesis HERE.
The tree is similar in
many respects to Acer
saccharum, sugar maple, and
Acer saccharum var. floridanum
(syn. A. barbatum), the Florida
maple, but features larger
leaves, and perhaps the
biggest samaras found in
Aceraceae. Our oldest tree is
located on the north side of the
headhouse in the SFA Mast
Arboretum and was planted in
1994, an acquisition made by Carl
Schoenfeld and John Fairey of
Yuccadoo Nursery who collected
seed from trees in Tamilupas,
Mexico. In spite of intense
competition with a Chinese
juniper, long since gone, our
Skuchii maple thrived without
irrigation or much attention during
the first few establishment years.
Let me tell you, this arboretum can
be hard on plants. Now over forty
feet tall with a 49” circumference
about four feet above the ground,
this tree sports excellent fall
foliage color, varying from
butterscotch yellow in some years
to reds, oranges and yellows in
others. New growth can be quite
striking on some clones, varying
from ruddy bronzes to pinks and
salmons. The bottom image on
this page is via Brian Upchurch, a
young tree featuring salmon
colored new growth. A queen of
marcescents, this tree can hold
leaves a very long time into the
winter. The two images at the top
of the document are early winter
shots - 2009 and 2010. Over the
years, we‟ve shared this species
with our gardening friends in
Austin, San Antonio and
Fredericksburg and they report it‟s
quite alkaline and drought tolerant,
certainly a plus for maplephiles in
those regions. However, Dr. Mike
Arnold, Texas A and M University, reports that Acer skutchii has failed to deal with the
high salinity irrigation water in College Station (250 PPM Na and 500 PPM
Bicarbonates). Whether irrigated
by sprinkler or microsprinklers,
growth was poor. Leaves were
cupped and took on a bluish cast,
and the trees failed to survive in
their container trials. I have
[personally seen the same thing
here in Nacogdoches county and
find the species leaf intolerant to
irrigation water that is burdened
with either Ca, Mg, or Na. Quite
tolerant if dripped or mircro
sprinklered and foliage is ufected
by the irrigation system.
We have germinated seed and
have had some success rooting
cuttings. In the fall of 2009, after
the samaras had fallen from our
sole tree, we applied about an
inch of composted pine bark fines
over the entire root zone. Lo and
behold, several thousand
seedlings emerged which were
carefully dug and shipped to a
wide variety of gardens, nurseries
and researchers in the USA.
Typically, ten percent or less of
our tree‟s seed are viable, most
are empty. As far as we know,
SFA may be the sole seed source
in the world!
To improve on seed availability,
viability and to seek out superior
clones, SFA Gardens planted 277
young one gallon seedlings in a
planting at SFA‟s Science
Research Center which is about
five miles from campus. This is a
cooperative project with the
College of Science and
Mathematics, a five year
agreement to use this space for plant
evaluation. Dr. Bea Clack is the lead
contact on this in that College.
Trees were planted on a 15‟ X 15‟
spacing in Dec 2010 and fertilized
with one cup of complete fertilizer in
Feb 2011. Weed control via
backpack sprayer application with
glyphosate.
After a record dry fal and
winter 2010 – and spring 2011,the
the decision was made to install a
drip irrigation system. ¾ inch black
poly pipe with ½ gph Netafim
emitters. Installed in mid-April 2011.
Bone dry subsoil. The irrigation
system guarantees survival of this
important plant material and once the
trees are a year or two old, they
should be able to deal with droughts
and dry times. This project is yet to
be successful. Will someone send
some real rain (April 26, 2011 note to
file).
Lijing Zhou, Graduate
research assistant in the Arthur
Temple College of Forestry and
Agriculture, helping out with inserting
the drip emitters
Success! Plan is to provide 4 to 6
gallons per week at the plant – the total applied
in two applications per week.
Of course, there are other maples suitable for central and western regions of
Texas. Dr. Mike Arnold, Texas A & M University, reports that in their work at College
Station, an Ed McWilliams selection of Acer rubrum var. drummondii, the Drummond
red maple, has been particularly tolerant of the high pH soils of College Station - and
tolerant to very poor quality water. A. buergerianum, Trident maple, has shown some
promise in western sites and there may be clones still untested that might surprise our
industry. Mike also reports that the Amur maple, A. tataricum ssp. ginnala (syn. A.
ginnala), has been a surprise in their inhospitable garden site. The Amur maple has
performed well here in Nacogdoches for over twenty years with bright red to burgundy
fall color. I have personally observed A. truncatum, Purpleblow or Shantung maple,
doing better under higher soil pH conditions than I expected, and Greenleaf Nursery will
soon be marketing a Keith Johanssen clone named „Fire Dragon‟ (Metro Maples http://www.metromaples.com/ ) that features red fall foliage. Many years ago, Benny
Simpson and Billy Hipps reported (American Nurseryman 177(5):26-35) that certain
provenances of A. grandidentatum, Bigtooth maple, and the Caddo maple, a unique
genotype of A. saccharum from southwestern Oklahoma, were particularly good
performers in higher pH soils. There are two superior varieties of Caddo maple, „John
Pair‟ and “Autumn Splendor‟. Still, when the dust settles on maples for western climes,
the list is not a long one. Skutch maple may be just another possibility. Growers
interested in seed or plants for evaluation should contact SFA Gardens.
Dave Creech, Director SFA Gardens – [email protected]