Thursday, August 2, 2012
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Seeing Ye/low
Each year I notice new
growth on plants and
shrubs that emerge in
shades of yellow• These
plants stand out from
trasts. You can easily try
yellow out as an accent or
visual draw in your home
garden. Here are some of
my favorites.
Carex 'Evergold' is a
wonderful grass• Grow
this in half day sun with
regular moisture. It will
perform well at the base
of shrubs, holding its
bright color throughout
the year. A fine contrast to
broad hosta foliage, I find
this twelve inch selection
much easier to grow than
the Japanese forest grass,
Hakonechloa.
Physocarpus opulifolius
'Lutea'; (Latin for yellow),
is commonly known as
Ninebark. Native to the
central states and growing
up to nine feet tall, this
deciduous shrub works
best as a background
plant. Too much shade
will send 'Lutea" foliage
back to a pale green. The
variety "Dart's Gold" tops
out at six feet and rates a
little brighter on the yellow
scale• Both varieties
require regular water and
six to eight feet to spread.
Berberis thunbergii
'Aurea' aka Golden Bar-
berry, is one of my all-time
favorite accent shrubs.
Deer-resistant, sun-loving,
rarely needing a trim, this
yellow will turn your
head! It will take some
drought once established,
but will retain the look of
vitality if watered weekly•
Small, round leaves are
interspersed with thorns,
growing two or three feet
tall and wide.
Sambucus is Latin for
elderberry• The popular
'Sutherland Gold' brings
brightness to a semi-
shaded corner. Use it as
a feathery backdrop for
smaller dark-green or
red-foliaged plants. As
By
the 'greens that dominate
gardens this time of year.
They provide contrasting
color as amid bright red,
purple and pink flowers•
Many plant breeders have
jumped on the wagon to
introduce yellow-foliaged
plants• In fact, the breed-
ers Seem to be ahead of the
preferences of most home
gardeners. For many years,
yellow color in a plant's
leaves alerts us that some
type of deficiency or exces-
sive watering is taking
place. Recently though,
this color has increased in
popularity with landscap-
ers looking for reliable,
low-maintenance con-
Carex 'Evergold' is a wonderful grass.
with most yellow-foliaged
plants, the leaves will age
to a light green. Water
Sutherland Gold on a reg-
ular basis and remember,
this elderberry is strictly
ornamental• Ingestion of
the raw berries may cause
nausea or vomiting.
These are only a few of
the choices• Columbines,
Hosta, Abelia and Spiraea
are also found in varying
yellow hues. Use a search
engine on the internet to
discover other yellow-
foliaged plants• Remem-
ber, too much of a good
thing can create a feeling
of havoc and unrest. Posi-
tion your plants wisely•
Sometimes I wonder
about the origins of phrases
and with this column all the
color phrases swarm around
my brain. Many are used
to describe human traits.
I can understand "turning
red" describing that actual
physiological occurrence
known as blushing• I
can stretch to imagine
"feeling blue" describing
a subdued mood (since
the color blue supposedly
calms and relaxes our
disposition)• But whoever
coined the phrases "look-
ing a little green" and "he's
yellow" was definitely not
a gardener• In the garden,
green describes the pic-
ture of health rather than
illness. Yellow foliage is
bold and daring rather than
cowardly• Are you feeling
a little daring? Does your
garden show it?
Horticulture Tips for August
Ordinarily I would pres-
enta.laundry list of tasks
fortile August landscape.
Unfortunately, the drought
has taken center stage and
for the water.
• If you have plants that
have not been mulched,
please consider doing so.
*Many woody shrubs and
: : ::B Keith Reed
is driving much of the
decision making concern-
in:.pur landscape. With
this in mind, here are some
colsiderations for this dif-
ficult stretch of weather.
i This goes without
saying but continue to
water important plants.
T"to water as deeply
as. possible and don't
be afraid to let the soil
surface dry a bit between
watering. If you have new
plantings, make sure and
water outside the planting
hole:enough that the roots
will be encouraged to
grow laterally and search
trees have yellowing and/
or dropping leaves now.
While this is indeed an
indicator of water stress,
it can be a good thing as
this is part of a plant's
survival mechanism. By
prematurely dropping the
leaves, water usage is
greatly reduced, allowing
the plant to better weather
the storm. Depending on
the species and the timing
of significant rainfall, trees
and shrubs may not try to
put additional leaves on
this season. If that is the
case, please do not assume
the plant has died without
at least doing this simple
check: Lightly scrape the
bark near the tips of grow-
ing branches. Any sign of
light green tissue indicates
the plant is still alive.
• Do not fertilize turf-
grass under severe drought
stress• Nor should you
attempt chemical weed
control under extreme
temperatures and drought
stress, except in very lim-
ited situations.
• Spider mites have
been a real problem for
many gardeners this year.
If you are continuing to
battle them, it may be
time to throw in the towel
as it will be very difficult,
if not impossible to gain
the upper hand on spider
mites in this weather. For
those with limited garden
space, your efforts may
be better spent remov-
ing the remaining plants,
prepping the soil as if to
replant, and solarizing it
OSU to host Ornamental
Plant Materials Conference
By Trisha Gedon
'Anyone who wants to
know the latest informa-
tion regarding ornamental
plant materials should
make plans to attend the
Ornamental Plant Mate-
rials Conference slated
Aug. 28 in Stillwater.
The conference is spon-
sored by the Oklahoma
Cooperative Extension
Service, Oklahoma State
University's depart-
ment of horticulture and
landscape architecture
and The Botanic Garden
at OSU. The conference
will take place at the
Wes Watkins Center on
the OSU campus.
• "We've got a great
conference planned and
we,re offering partici-
pants the opportunity to
take home a lot of valu-
able information," said
Mike Schnelle, OSU
Cooperative Extension
ornamental floriculture
specialist• "The infor-
mational workshops are
geared toward industry
specialists such as land-
scapers, nursery person-
nel, greenhouse growers
and master gardeners, as
well as individuals who
are gardening hobbyists.
You don't have to be
a horticultural profes-
sional to attend the con-
ference."
Early registration is $85
and must be postmarked
by Aug. 17. Botanical
Garden members, Exten-
sion educators, Master
Gardeners and Linnaeus
Gardeners may register
early for $60. All reg-
istration will be $130
after Aug. 17. Lunch is
included in the registra-
tion fee. To register for
the conference, contact
Stephanie Larimer at
405-744-5404, or email
her at stephanie.larimer
@okstate.edu.
Workshops will be
taught by a number of
industry and academic
specialists. A descrip-
tion of workshops is
available online at http:
//www.hortla.okstate.edu/
• Workshop topics will
include overviews of
appropriate native and
adapted non-native plants
for Oklahoma and periph-
eral states•
"I think anyone who
attends this conference is
sure to gain a lot of valu-
able information. The con-
ference is offering a wide
variety of topics, so there
is something for every-
one," Schnelle said.
by covering it with plas-
tic. This should help with
insect and disease control
for next year.
• Read up on gardening
topics such as drip irriga-
tion, rainwater collec-
tion, landscaping using
Spider mites
native plants, building
healthy garden soils and
Xeriscaping.
If you have question or
concerns about these or
other Horticulture issues,
contact Keith Reed. He is
the Horticulture Educator
in the Payne County OSU
Extension office. You can
contact him via email at
keith.reed@okstate.edu,
call 405-747-8320, or
stop by the Extension
office at 315 W. 6 th in
Stillwater.
Giant Wasp: Friend or Foe ?
Someone's first encounter
with a Cicada killer can be
a disconcerting experience.
These very large yellow and
black wasps (about an inch
and a half long) are fairly
common in our part of the
world. The assumption is
that any wasp this big with
a stinger must be bad. This
is perfectly understandable
but in reality this insect
is rarely a real problem
for anything other than
the cicada (locust). The
wasp stings and kills the
cicada and drags it to its
burrow where it becomes
the food source for the next
generation. The burrows
are easily recognized as a
hand sized mound of soil
around a thumb sized hole.
These burrows are often
in bare soil areas such as
flower beds and vegetable
gardens.
Although rare, female
Cicada killers can sting
people. Please note that
they will generally only
do so when provoked• The
male Cicada killer is more
I
By Keith Reed
aggressive but does not
have the capacity to sting•
These insects are normally
solitary although it is not
uncommon to see several
in one area. With these
extremely dry conditions,
you can expect to see an
increase in activity at
water sources such as bird
baths and animal watering
dishes•
In situations where con-
trol is warranted, there are
a couple of options• Any
knock-down wasp product
will be effective provided
you can catch them when
they are not moving (not
an easy thing tO do). The
best control option is to
treat the individual mounds
with a small quantity of
insecticidal dust labeled for
wasps• As the wasp crawls
in and out of the burrow, it
will come in contact with
the insecticide. Retreat-
ment may be necessary in
the case of rain or heavy
irrigation. Broadcast appli-
cations of general purpose
insecticides are not particu-
larly effective for control of
this insect•
If you have questions
or concerns' about this or
other Horticulture issues,
contact Keith Reed, the
Horticultural Educator in
Payne County OSU
Extension office• You can
contact him via email at
keith.reed@ okstate.edu,
call 405-747-8320, or stop
by the Extension office at
315 W. 6 h in Stillwater.
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