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Written by: Matt Nespeca
Invasive Species Consultant
cell: 843-833-5250
Overview:
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Picture 1: Indiangrass establishment on an
old agricultural field
in Horry County, SC, 2 years after establishment
(photo courtesy of Laura Fogo, USFWS)
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Due to enhanced visual and wildlife values that
can be attained with native plant restoration, there is much interest
among southeastern landowners to re-establish native warm season
grasses (NWSG) on their property.
When establishing NWSG on fallow fields, pastures, or open areas,
it is not always necessary to drill new seed. NWSG seed can remain
in the seed bank for a very long time, sometimes when pasture grasses
and other competitive weeds are controlled, NWSG like broomsedge,
little bluestem, purple top and other species are released by the
initial disturbance. After initial site preparation treatments,
always monitor the existing vegetation to see if you already have
a good native species component. Whether managing for quail habitat,
aesthetics, or ecological restoration, sometimes just ridding a
field of bermudagrass or bahiagrass is enough to restore a lot of
natural cover and structure.
When choosing NWSG species to drill on open field areas, always
search for the most local ecotypes that are available among the
species that you would like to plant. Native grass sources like
Ernst Conservation Seeds, LLP (www.ernstseed.com) can provide regional
seed mixes, and there is an effort among conservation groups and
agencies to build very specific seed sources for regional projects.
Fluffy NWSG seed is very difficult to plant with conventional equipment.
Specialized NWSG no-till drills (such as Truax drills or Great Plains
drills) are very effective. Even though these drills are expensive,
there may be specialized drills available for rent through local
Natural Resource Conservation Service or Soil and Water Conservation
District offices. There are consultants who specialize in NWSG establishment,
and in many cases, it may be more effective to contract with a professional
for the initial installation of native grass projects.
The best long-term restoration and maintenance tool for native warm-season
grasses is prescribed fire. When used in combination with properly
timed herbicide treatments, prescribed fire can rejuvenate the composition
and structure of native grasses. Prescribed fire is not always possible
on all sites, but it should be considered as a restoration tool
whenever possible.
As with any vegetation management activity on land, be sure to read
all herbicide labels and literature before application.
Native Warm-Season Grass Restoration on Pastures and Old
Fields
When restoring NWSG on pastures and old fields, you will
generally need to implement several different vegetation management
treatments, including site preparation, pre-plant, and maintenance
treatments.
Site Preparation
On established pastures, grasses such as bermudagrass and
bahiagrass should be controlled in advance of planting or restoring
NWSG.
A good strategy for controlling bermudagrass would involve either
mowing or burning the site in early Spring, followed by multiple
sequential treatments with Accord® XRT II, or other glyphosate-based
product. An example of a treating schedule would be to treat the
pasture with three sequential applications of 2 quarts/acre of Accord
XRT II in the same season (for example, May, July, and September).
This treatment strategy will reduce the component of bermudagrass
on the site, and create open ground for either natural recolonization
or planting of NWSG.
With bahiagrass pastures, if there is no NWSG evident on the site,
the same sequential treatment method can be utilized. If NWSG such
as broomsedge, bushy bluestem or little bluestem are already in
place within the pasture, you may choose to control the bahiagrass
with a sequential treatments using selective herbicides such as
Escort® XP plus a surfactant, since Escort XP at a low use rate
does not significantly effect many NWSG species, but will control
bahiagrass, as well as blackberry, crown vetch, sericea lespedeza,
and many other plants that could out-compete native grasses
Fallow agricultural fields that are dominated with annual grasses
and broadleaf weeds are much easier to prepare for NWSG establishment.
Usually, one or two sequential site preparation treatments with
glyphosate plus surfactant in the summer and fall in advance of
planting NWSG will be sufficient to prepare the soil for planting.
Pre-Plant Treatment
A pre-plant treatment can be implemented either immediately
before or immediately after drilling NWSG seed on the site. The
purpose of a pre-plant treatment is to keep weedy competition from
impeding good germination and establishment of the native grasses.
Most seeding of NWSG is done in Fall or Spring, and a treatment
with a product like Journey® will prevent annual grasses and
broadleaf weeds from emerging, but allows for NWSG germination and
establishment. A treatment of Journey or Journey plus Accord®
XRT II will provide an excellent weed barrier for the first season
after planting.
Maintenance Treatments
After a field is established in NWSG, there are still maintenance
treatments that can selectively remove unwanted plants such as bermudagrass,
bahiagrass, vasseygrass, or broadleaf weeds, hardwoods and vines.
Maintenance treatments are extremely specific to the species of
NWSG that is being established or restored, as well as the weed
species. For example, a broadcast treatment of Escort XP can control
bahiagrass, but will not control big bluestem, little bluestem,
or indiangrass. A broadcast treatment of Plateau® can control
vasseygrass and fescue, but will not control big bluestem, little
bluestem, or indiangrass.
When bermudagrass continues to be a re-emerging problem in a NWSG
field, the best method to control bermudagrass is to treat the patches
of bermudagrass with a product like Arsenal® AC before the patches
can threaten the entire stand of native grass.
Broadleaf weeds, hardwoods and vines can be selectively removed
out of NWSG with products such as Garlon® 4 Ultra, while maintaining
safety for the native grasses.
For most weed problems, there are treatment options to consider
if the native grass is at risk, or if the weeds are negatively effecting
the wildlife habitat or aesthetic values of the site.
Case Study:
McAlhany Preserve Native Warm-Season Grass Establishment
Landowner: Charleston Natural History Society
Location: Coastal Plain, South Carolina
Beginning Site Condition: Loblolly pine plantation
Size of native grass establishment: ~ 7 acres (surrounded
by 23 acres of longleaf pine and wiregrass restoration)
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| Picture 2: Feb ’07, site prepared native
grass planting area,McAlhaney Preserve (photo by Joe Cockrell) |
Picture 3: June ’07,
after drilling indiangrass, little bluestem, and big bluestem
(photo by Matt Nespeca) |
Picture 4: September ’07, excellent
indiangrass emergence as well as other native grasses (photo
by Sudie Daves) |
Native Grass Establishment Treatment Schedule
Summer, 2005: Timber harvested
Fall, 2005: Mechanical site preparation (dragged,
piled and disked) of grass plots
Winter, 2006: Prescribed burned
Fall, 2006: Chemical Site Preparation
Method: Ground Broadcast (skidder)
Treatment: 5 quarts/acre Razor Pro Herbicide plus
1 quart/acre Garlon 4 Herbicide plus 1% surfactant
Volume: ~25 Gallons per acre
Spring, 2007: A Truax drill was used to plant the
site with indiangrass, little bluestem, and big bluestem. Several
species of wildflower were drilled as well.
Spring, 2007: 2 days following planting, pre-emergent
herbicide treatment:
Method: Ground Broadcast (tractor)
Treatment: 10.7 oz./acre Journey Herbicide plus
½ % nonionic surfactant
Volume: ~20 Gallons per acre
Result To Date: Excellent germination and survival
of indiangrass, little bluestem and big bluestem
Native Grass Restoration on Forest Sites
Heavily thinned forest sites can be excellent areas to
conduct native warm-season grass restoration, even if the sites
are generally too rough to drill seed. Understory hardwood control
treatments with products like Arsenal® AC or Garlon® 4Ultra
can open the forest up to sunlight, and release native grasses and
forbs.
Thinned loblolly or longleaf pine stands with heavy hardwood
understory and midstory
When sweetgum, maple, yellow poplar and other hardwoods
are heavy in the understory and midstory, ground broadcast herbicide
treatments can be conducted by ground by tractor, ATV, skidder or
backpack crew. Treatments with Arsenal AC provide excellent long-term
hardwood control, while maintaining safety for the overstory pines.
Arsenal AC is a selective herbicide, and does not control many legumes
or blackberry, and annual forbs and grasses will generally recolonize
due to the increased sunlight that reaches the forest floor after
controlling low quality hardwoods.
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| Picture 5: Heavy
understory of sweetgum, maple and pepperbush. Hampton County,
South Carolina |
Picture 6: Skidder
treatment in August with 16 oz/acre Arsenal AC plus 16 oz/acre
Garlon 4 plus surfactant. |
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| Picture 7: One
year after Treatment- With grass recolonization and reduced
Hardwood understory component. |
Picture 8: The
same site 8 years after treatment, excellent native grass recolonization,
Hardwood understory component. with periodic winter burning
following treatment. |
Thinned loblolly or longleaf pine stands with scattered
undesirable hardwood understory and midstory
When sweetgum, maple, yellow poplar and other hardwoods
are scattered in the understory and midstory, spot foliar herbicide
treatments can be conducted by ground by tractor, ATV, or backpack
crew. Spot foliar treatments with Arsenal AC provide excellent long-term
hardwood control, while maintaining safety for the overstory pines.
If good native grass cover is already in place, spot foliar treatments
will allow direct treatment of undesirable hardwoods, and the applicator
should avoid foliar contact with desirable grasses. Some herbicide
contact with desirable grasses is inevitable, but the final result
will allow for significant amounts of native plant recolonization
due to the high level of newly created sunlight gaps because of
the controlled hardwoods.
Thinned mixed pine/hardwood or hardwood stands
When undesirable hardwood sprouts are heavy under an overstory
of desirable hardwoods, Garlon 4 Ultra is an excellent product that
provides excellent NWSG selectivity and safety for overstory hardwoods,
while controlling many undesirable hardwood sprouts such as sweetgum,
oaks and waxmyrtle. This treatment is most effective when implemented
in combination with prescribed fire follow-up treatments. In many
cases, follow-up spot herbicide treatments will be necessary to
control all undesirable hardwood components. As with most herbicide
treatments, both rate and timing are very important factors to consider
when treating undesirable hardwoods, while trying to maintain native
plant components.
About the author: CWC Chemical
employs Matt Nespeca as an invasive species consultant. Matt has
12 years of experience in vegetation management, and has worked
extensively with complex invasive plant problems throughout the
southeast. He worked for 7 years for BASF Corporation as a technical
specialist, sales representative and product manager. Matt has a
M.S. in Forest Biology from Virginia Tech, and a B.S. in Forest
Resource Management from Auburn University. Matt is both a registered
forester and commercial applicator, and partners with a network
of specialized applicators and professionals to provide results
for landowners, land managers and other clients.
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