NutSedge, Manage & Fruit Trees/Bushes
Bunny McElwee
purple and yellow (isn't that nice!). Once I finally found out what this
plant was, I was told how to get rid of it - Manage. And get rid of it I
did - 6 times. I spray, it dies, 6 weeks later, its back again. I spray, it
dies, it comes back. It gets cold (winter), it goes away, it gets warm
spring), it comes back again. So, I figure this is a life long project that
I will so happily be spending my time doing. However, now I have planted
fruit trees and I still have to kill this NutSedge. As you all know who have
had or seen NutSedge, you can not pull it (that just makes more), it will
grow right through the thickest of mulch and weed barrier you can put down,
and there are only two or so products I even know of that kills it. My
questions is, what kind of problems am I going to have using Manage around
my fruit trees? The NutSedge will find its way into my mulched areas around
my fruit trees, without question. But if I can keep it down outside the
mulched areas, how close can I get to the actual tree/root system before I
have a problem?
Thanks in advance! I appreciate all the help with my last few questions.
Everyone has been extremely helpful!
--
Bunny McElwee
her91...@sc.rr.com
'91 Mariner Blue - BlueFlash (we call her Blue for short <G>)
License Plate - IXCLR8
JRSC, Chrome all over, Double Hoop Style Bar, silly grin (driver and car!)
and too much more to list.
Allegra
What little I have read about NutSedge was from
this bulletin from UCDavis and I am copying it to
you from my files. I hope it helps, there is a reason
why is called the world's worse weed! Good luck,
Allegra
in zone 6-7 in Portland Oregon
"Nutsedges are common weeds in landscapes and gardens in the coastal
valleys, Central Valley, and southern areas of California. They thrive in
water-logged soil and their presence often indicates that drainage is poor,
irrigation is too frequent, or sprinklers are leaky. Once established,
however, they will tolerate normal irrigation conditions or drought. The two
most common species of nutsedge in California are yellow nutsedge [106K]
(Cyperus esculentus) and purple nutsedge (C. rotundus). Yellow nutsedge is
found throughout California, whereas purple nutsedge is found mostly in the
southern portions of the state.
IDENTIFICATION
Although nutsedges are often referred to as "nutgrass" and resemble grasses,
they are not grasses but true sedges. Their leaves are thicker and stiffer
than most grasses, and are arranged in sets of three [74K] at the base,
whereas grass leaves are opposite in sets of two. Nutsedge stems are solid,
and when looked at in cross-section, they are triangular; grass stems are
hollow and round, and in cross-section they are almost flat or oval.
Nutsedge has three long, leaflike bracts at the base of each flower head.
Yellow nutsedge has light brown flowers and seed, and purple nutsedge
flowers have a reddish tinge and the seed are dark brown or black.
Yellow and purple nutsedges produce tubers, which are incorrectly called
"nuts" or "nutlets," thus the origin of its common name. These tubers are
produced on rhizomes (underground stems) that grow as deep as 8 to 14 inches
below the soil surface. Buds on the tubers sprout and grow to form new
plants; thus individual nutsedge plants eventually form patches that can
range up to 10 feet or more in diameter. Yellow nutsedge produces round,
smooth, brown or black tubers that are about 1/2 inch at maturity. Only one
tuber is formed at the end of a rhizome. Tubers of a yellow nutsedge plant
have a pleasant almond taste. Tubers of purple nutsedge plants are covered
with red or red-brown scales and are formed in chains with several tubers on
a single rhizome. These tubers are bitter to the taste.
Be careful not to confuse yellow or purple nutsedge with tall umbrella sedge
(C. eragrostis),another perennial sedge that is found in wet, soggy soils.
Tall umbrella sedge is a large, light green sedge that does not produce
tubers. It spreads by seed or by new plants that form on short, thick
rhizomes around the base of the mother plant. If left unmowed, it grows
taller than yellow nutsedge, but in a mowed turf it can be distinguished
from yellow nutsedge by its wider leaves and stems, its short, thick
rhizomes, its lack of tubers, and its tendency to grow in tight clumps that
are less than 1 foot in diameter.
Another weed often confused with nutsedges is green kyllinga (Kyllinga
brevifolia),which is also a major problem in turf and ornamental plantings
(see UC IPM Pest Notes: Green Kyllinga, Publication 7459). The flower of
green kyllinga is visibly different from that of nutsedge, and the plant
does not produce tubers.
LIFE CYCLE
Yellow and purple nutsedges are perennial plants. Their leaves and flowering
stalks generally die back in fall when temperatures decrease, but tubers and
rhizomes survive in the soil and sprout the following spring when soil
temperatures remain above 43°F for yellow nutsedge or 59°F for purple
nutsedge. The majority of tubers can be found in the top 6 inches of soil
where they can survive for 1 to 3 years. In field crops, research indicates
that most plants sprout from tubers, and seed do not contribute much to the
spread of nutsedge; however, no work has been done to examine the role of
seed in the spread of nutsedge in the landscape.
DAMAGE
Nutsedges are a problem in the lawn because they grow faster, have a more
upright growth habit, and are lighter green in color than most grass
species, resulting in a nonuniform turf. In gardens and landscapes,
nutsedges will emerge through mulches [85K] in shrub plantings and vegetable
and flower beds throughout the growing season.
MANAGEMENT
Tubers are key to perennial nutsedges' survival. If you can limit production
of the tubers, then the nutsedge will eventually be controlled. To limit
tuber production, remove small nutsedge plants before they have five to six
leaves; in summer this is about every 2 to 3 weeks. Up to this stage, new
tubers have not yet formed. By removing as much of the plant as possible,
the tuber will be forced to produce a new plant, drawing its energy reserves
from tuber production to the production of new leaves. Continually removing
shoots eventually depletes the energy reserves in the tuber because 60% of
the reserves are used to develop the first plant and 20% for the second.
However, mature tubers can resprout as many as 10 to 12 times. Even though
these newer sprouts start out weaker than the previous ones, they will
gradually resupply the tuber's energy reserves unless they are removed.
The best way to remove small plants is to pull them up by hand or to
hand-hoe. If you hoe, be sure to dig deeply (8 inches) to remove the whole
plant. Using a tiller to destroy plants will only spread the infestation,
because it moves the tubers around in the soil. However, repeated tillings
of small areas before the plants have six leaves will reduce populations.
Many people mistakenly use systemic herbicides such as glyphosate to try to
kill the tubers after the plant is fully grown. Unfortunately, when tubers
are mature there is little translocation of the herbicide from the leaves to
the tubers, thus tubers are not affected.
If nutsedge is found in small patches in turf, it may be best to dig out the
patch to about 8 inches deep, refill, and then seed or sod the patch.
Biological control of nutsedge using insects and plant pathogens has been
researched, but as of yet has not provided consistent control. An unexpected
control of nutsedge may come from sweet potato tissue. Sweet potato tissue
has been shown to contain chemicals that suppress the growth of nutsedge
roots, but no one has yet isolated the chemical that is responsible for this
effect.
In addition to consistently removing the small plants, nutsedge populations
can be reduced by shading, drying, mulching, and with properly timed
applications of herbicides.
Drying
During the middle of the summer, purple nutsedge can be controlled by
cultivating the infested area and then withholding all moisture to allow the
sun to dry the tubers. Repeated tilling and drying is required to give good
control. This method is only effective in areas where other plants do not
need irrigation. Drying is not effective for the control of yellow nutsedge.
Shading
Nutsedges do not grow well in shade. By changing landscape plantings you may
be able to reduce their growth with shade. For example, a highly infested,
annually planted flower bed may be better off replanted with a tall, dense,
ground cover or shrub that would shade out the nutsedge. Low-growing ground
covers will not shade out yellow nutsedge.
Mulching
The commonly used black polyethylene mulches do not control yellow or purple
nutsedge because the sharp points at the ends of the leaves can penetrate
them. Newer landscape fabrics made from polypropylene polymers are available
that effectively suppress nutsedge growth (see table below) and have the
added benefit of being water and air permeable, unlike polyethylene. If the
planting permits, mulching with a landscape fabric, with or without an
organic mulch on top, will suppress nutsedge growth. For complete control,
however, you will still need to remove any emerging nutsedge plants.
Effectiveness of Landscape Fabrics in Suppressing
Emergence of Yellow Nutsedge.
Landscape fabric
Number of shoots pentetrating fabric after 30 days in greenhouse
Dupont Typar 307
0.0
Dupont Typar 312
0.0
Weed Barrier Mat
0.3
Geoscape Landscape Fabric
0.8
Dewitt Pro 5
1.0
Weedblock Fabric
1.8
Amoco Rid-a-Weed
2.5
Phillips Duon Fiber
3.3
Control
8.3
Adapted from C. A. Martin, H. G. Ponder, and C. H. Gilliam. 1991. Evaluation
of landscape fabrics in suppressing growth of weed species. J. Environ.
Hort. 9:38-40.
Chemical Control
Few herbicides have been effective in controlling nutsedge, either because
of lack of selectivity to other plants or lack of uptake. Apply herbicides
when they will be most effective (see table below). Postemergent
(nonselective) herbicides that are currently available to help control
nutsedge in the home landscape include pelargonic acid (Scythe), MSMA, and
glyphosate (Roundup). These herbicides require repeated application and
their use will only result in limited suppression of these weeds. MSMA is
more effective on yellow than purple nutsedge. A postemergent herbicide that
has some selectivity, particularly in turf, is halosulfuron (Manage). This
is a rapidly translocated herbicide, but to be effective, this and other
postemergent herbicides must be applied to nutsedges before the fifth leaf
stage, when the plant is still building its energy reserves in the tubers by
translocating from the leaves to the newly forming tubers. After this stage,
translocation to the tubers slows down or ceases and the herbicide will only
kill the aboveground portion of the plant, leaving the tubers unaffected.
Controlling Nutsedge with Chemicals.
Herbicide
Commerical name
Apply before seed germinates
Apply to young plant
Readily available to home gardener
dichlobenil
Casoron
Norosac
yes
no
yes
EPTC
Eptam
yes
no
yes
glyphosate
Roundup
no
yes
yes
halosulfuron
Manage
no
yes
no
metolachlor
Pennant
yes
no
no
MSMA (crabgrass and nutsedge control)
no
yes
yes
pelargonic acid
Scythe
no
yes
yes
Apply glyphosate when the plants are actively growing and have not been
recently mowed or cut. Be sure to read the label and determine how much time
after application before an irrigation can be applied. Do not apply if
rainfall is expected within 24 hours of application. Glyphosate works most
quickly when the weather is warm and sunny. Activity may be delayed if it is
cool or cloudy following application. MSMA is also translocated and must be
applied to actively growing plants younger than the fifth-leaf stage.
Pelargonic acid is also most effective when applied on a warm, sunny day.
This chemical will not be affected by rain 2 hours after spraying. Because
pelargonic acid does not move through the plant, you need to thoroughly
cover the entire aboveground portion of the plant with spray to kill it. Do
not spray either herbicide when it is windy or other plants may be injured
[50K] from the spray drift. Halosulfuron is used in such minute amounts that
the manufacturer markets it in premeasured, water-soluble bags. Follow all
label directions for optimal control of nutsedge, and be sure to add a
nonionic surfactant to the spray solution.
Preemergent herbicides available to reduce yellow nutsedge include
dichlobenil (Casoron, Norosac), EPTC (Eptam), and metolachlor (Pennant). Of
these, metolachlor is more effective than EPTC and safer around many
ornamentals than dichlobenil, but it must be applied by a licensed pesticide
applicator. No preemergent herbicides can be used on turfgrass but they can
be used on selected ornamental plants. Read the label directions to see
which orna-mentals will tolerate each herbicide. Metolachlor and EPTC must
be incorporated mechanically 3 to 4 inches to place the herbicide in the
soil so yellow nutsedge will take up the chemical through the shoot as it
emerges. The use of preemergent herbicides reduces the number of emerging
nutsedge plants, but for long-term control, retreatment is necessary."
"Bunny McElwee" <corv...@sc.rr.com> wrote in message
news:vbdA8.26094$qV.85...@typhoon.southeast.rr.com...
Nicole H
beds. I will be using a weed flamer on it this weekend.... I'll let you
know how it works and if the sedge comes back.
Nicole
bryan lafleur
> beds. I will be using a weed flamer on it this weekend.... I'll let you
> know how it works and if the sedge comes back.
It will make you feel a lot better, but wont kill the tubers. I see
the worst nutsedge problems where people have brought in "topsoil" to
raise beds.
Have fun,
Bryan
Tom Jaszewski
wrote:
> Three years ago I acquired the wonderful plant known as NutSedge. Both
>purple and yellow (isn't that nice!). Once I finally found out what this
>plant was, I was told how to get rid of it - Manage. And get rid of it I
>did - 6 times. I spray, it dies, 6 weeks later, its back again. I spray, it
>dies, it comes back. It gets cold (winter), it goes away, it gets warm
>spring), it comes back again. So, I figure this is a life long project that
>I will so happily be spending my time doing. However, now I have planted
>fruit trees and I still have to kill this NutSedge. As you all know who have
>had or seen NutSedge, you can not pull it (that just makes more), it will
>grow right through the thickest of mulch and weed barrier you can put down,
>and there are only two or so products I even know of that kills it. My
>questions is, what kind of problems am I going to have using Manage around
>my fruit trees? The NutSedge will find its way into my mulched areas around
>my fruit trees, without question. But if I can keep it down outside the
>mulched areas, how close can I get to the actual tree/root system before I
>have a problem?
> Thanks in advance! I appreciate all the help with my last few questions.
>Everyone has been extremely helpful!
Manage will work, If it appears to be coming back you may be spraying
late in its growth cycle. Follow those directions to the letter.
Regards,
Tom
Successful gardening is doing what has to be done when it has to be done
the way it ought to be done whether you want to do it or not.
Nicole H
with nutsedge, the farmer burns the entire field to get rid of the sedge.
I'm hoping this will work.
I think the nutsedge was brought in with the compost(free compost of the
city) My raised beds are at a school and the compost is the only thing that
each bed has in common.
I can't use Manage since we are organic so the flamer is my only hope. It's
impossible to get the students to dig it out properly.
Nicole
"bryan lafleur" <blaf...@hotmail.com> wrote in message
news:a0190c9c.02050...@posting.google.com...
Tom Jaszewski
On Sun, 05 May 2002 19:37:39 GMT, "Nicole H"
<nhightow...@bak.rr.com> wrote:
>Are you sure it won't kill the tubers? When an alfalfa field gets infested
>with nutsedge, the farmer burns the entire field to get rid of the sedge.
>I'm hoping this will work.
>
>I think the nutsedge was brought in with the compost(free compost of the
>city) My raised beds are at a school and the compost is the only thing that
>each bed has in common.
>
>I can't use Manage since we are organic so the flamer is my only hope. It's
>impossible to get the students to dig it out properly.
There are some documented figures on temperature and duration for
solorazation. It does work but may require a substantial period of
time at recommended temperature.
Soil solarization is most effective during the summer months, and may
be less effective
in cooler climates (DeVay 1990). The higher the temperature, the more
quickly a kill is
achieved. Solarization is effective only if done in wet soil. Where
soils are typically dry,
they must first be irrigated until soil from the surface to 50 to 60
cm deep is at field
capacity (Grinstein & Hetzroni 1991).
MANAGEMENT FAVORING/DISCOURAGING SURVIVAL:Limit tuber production and
drain tuber energy reserves by repeatedly removing small plants before
the 6-leaf stage (every 2-3 weeks in summer). Mature tubers can
resprout up to ~12 times. Shading or solarization can reduce
infestations by weaking shoots and decreasing new tuber formation, but
mature tubers may not be eliminated. Cultivation can worsen an
infestation if not repeated often enough to exhaust tubers and prevent
new tuber formation.
yellow nutsedge: Pigs relish tubers and can search out, uncover, and
consume most tubers in an area within a period of days.
purple nutsedge: Thorough deep cultivation (~ 30 cm deep) to fragment
tuber chains and cover green parts, followed by persistent repeated
cultivation (~15 cm deep) to kill new shoots and limit new tuber
formation, especially when the soil is dry.
Tom Jaszewski
wrote:
>There are some documented figures on temperature and duration for
>solorazation. It does work but may require a substantial period of
>time at recommended temperature.
Solarization: Covering moist ground with 1 or 2 sheets of clear
plastic sheets for 4-6 weeks during the warmest time of year will
raise the temperature to 100-130oF in the top 2 inches and 90-97oF 18
inches deep. This may be sufficient to kill shallow tubers.
Nicole H
time.
Our summers are horrible... frequently in the 100s... never below 90... we
even had a week of 110.
I'm definitely going to solarize this summer. Just clean out the plot,
water well and then throw the plastic on? My plots are 4ft wide by 20ft.
What's the best way to anchor the plastic?
Thanks Tom
Nicole
Tom Jaszewski
You'll need to water to keep it moist. I use a couple of layers of
black and use wood strips with stakes to keep plastic in place.
Nicole H
Do I have to keep watering the soil? Or just water it one time and then
leave it alone?
Thanks in advance
Tom Jaszewski
Keeping the soil moist will help insure the temp gets high enough to
kill the nutlets.