Tallgrass Restoration Manual
Copyright 2004 Native Prairies Association of Texas
DIVERSITY
Based
on work over the last 70 years, it is evident that the prairies in Texas had
an incredible diversity of species that supported a vast array of animals.
Texas prairies vary widely in species composition.
Different topographies, elevations and aspect to sun affects local
species composition, as well as micro-relief, such as gilgai or mima mounds or
a buffalo wallow. The size of the
prairie remnant and its’ past history of use will also have a huge impact on
what species survived.
The big four are vigorous summer growing perennials that are
characterized by having wide leaves catching a maximum of sunlight energy and
have deep penetrating root systems that draw a maximum amount of soil moisture
and plant nutrients. They can grow from 5 to 8 feet in height and provide
quality nutrition for hungry animals. They provide nesting for upland game
birds and habitat for many small animals. These plants are excellent for
reclamation projects to provide ground cover, to catch snow in the winter and
to prevent soil erosion.
Selecting Grass Species:
In selecting which species of grass to plant, it is important to
recognize which combination of the big four and other grass species were once
dominate in the area that you want to restore. The Tallgrass Grassland Series
has been described as four broad arrangements based on specific dominance of
the big four, according to David Diamond and Dr. Fred Smeins:
SERIES
PLANT ASSOCIATIONS
REGION OF OCCURRENCE
Little
bluestem-Indiangrass
Little bluestem-Indiangrass
Blackland Prairie Alfsols and the San Antonio Prairie
Little bluestem-Indiangrass-Big bluestem
Blackland and Fayette Prairie
Little bluestem-Big bluestem- Indiangrass
Blackland Prairie Mollisols and
Little
bluestem-Brownseed Paspalum
Little bluestem-Brownseed Paspalum-
Indiangrass Fayette Prairie Alfisola and the
Silveanus
Dropsed
Silveanus Dropsed-Mead Sedge
Northern Blackland Alfisols
At the time of European settlement, the
plains area of North America gave way to the plow and a large percentage of the
Tall Grass prairies were destroyed. There
is a need to re-establish these species and preserve the heritage of the Tall
Grass prairie that nature provided us in the beginning.
The big four prairie grasses grow in a variety of soils including
those of shallow depth, low pH and low fertility. In low pH soils (5.5 and
lower), the addition of lime will be necessary. Other species need to be included in a native grass planting
in order to maximize diversity. Additional grasses may include eastern gamma
grass, sideoats gramma, tall dropseed, Texas cupgrass, Texas wintergrass,
brownseed paspalum, fimbry, purple three-awn, Canada wildrye, Florida paspalum,
microdentate sedge, Carolina jointtail, Mead sedge, Silveanus dropseed, tridens
sps. Among the forbs, the following were found to be dominant in little
bluestem-Indiangrass remnant prairies: false dragonhead, old plainsman, prairie
acacias, bishops and bluets as well as prairie coneflower. Among the Little
bluestem-Brownseed Paspalum remnants, button snakeroot and compass plants were
dominants, as well as heath and silky asters, Indian plantains, meadow pinks,
sensitive briars and Ruellia sps. In
wetter areas, brown-eyed susans, Maxmilian sunflowers along with the
aforementioned acacias, bishops, coneflowers and sensitive briars, as well as
camphorweed are prevalent. In the northern Silveanus Dropseed-Mead Sedge
associations, brown-eyed susans, cudweed, flax sensitive-briar, silky aster and
yellow-puffs are common.
Ultimately, the species that will dominate in a given area will
depend on management, soil characteristics and climatic conditions.
Do not limit yourself to the listed species above, though - use them as a
guideline. Find any remnant
prairies in your area and determine the species composition.
It is important to know its past management history, i.e. how often and
how intense has it been grazed or hayed? Has
it been sprayed with broad-leaf herbicides?
Remember to include appropriate legumes, such as plants of the genera
Desmanthus, Baptisia, Cassia, Dalea, Astragulus and
Psoralea.
These will add fertility to the soils over time.
The main point is diversity. The more species, the more resilient
the prairie to drought and other catastrophes, and the more it can support a
greater variety and number of birds, mammals, insects and reptiles, not to
mention the aesthetic appeal to the human eye.
ESTABLISHMENT
The following is a list of planting methods, techniques, and
guidelines:
Planting method
Planting Technique
Planting
Guidelines
Broadcast
Fertilizer spreader
Mix with disperser, good for large
acreage
Air seeder
Same as above
Chaffy
seed spreader Good for small acreage, difficult to
calibrate
Hand broadcast
Good for small acreage
Hydro-seeder Uses a hay mulch and water as carrier
Seedballs
Good for small to medium acreage or where
rocky soil precludes the use of seeding equipment.
Seed hay
Good method of obtaining local genotypes
/ ecotypes
Drilling chaffy seed Chaffy seed drill There are several drills on the market designed to meter.
Drills can be rented from an National Resource Conservation Service
(NRCS) district. Good for large acreage.
Grain
drill
Must
mix seed with fertilizer. Not good for grain box if used on large acreage
Live
plants
Planted by hand
Plants are started from seed, placed in
Pots, and grown in the green house. This method is very labor
intensive, and best suited to small areas.
Bare roots
Planted by hand
Roots are taken from live plants, placed in a prepared seedbed and watered in.
Very high survival rate. Well suiteds
mall garden landscapes
Planting
mixtures typically range from 8 to 20 pounds of pure live seed per acre.
Due to seed costs, low input planting methods must be considered for large
acreage. Suggested pure live seed planting rates are:
*
Big bluestem
3 to 7 lbs. per acre
*
Indian grass
3 to 6 lbs. per acre
*
Switchgrass
½ to 1 lbs. per acre
*
Little bluestem
3 to 6 lbs. per acre
*
Wildflower Mix
10 to 20 lbs. per acre
Seedbed,
Broadcasting and Drilling:
Preparing
a seedbed is the most assured method of high establishment rates.
The seedbed at planting time should be firm and free of vegetation.
Seedbed preparation can require several trips over the ground with a plowing
disk, a drag to smooth the seedbed and lastly a roller packer to firm the
seedbed just before planting. If the seed is broadcast planted a second trip
with the roller packer will be necessary to cover the seed (¼ to ½ inch in
soil depth) and to insure good seed/soil contact. Old fertilizer spreaders are
very effective when broadcasting over larger areas. If the seed is drilled, some
types of drill seeders have packer wheel attachments that will press the seed
into the soil surface, giving it good seed soil contact. There are also drills
especially designed for planting native grass seeds. These are equipped to meter
out chaffed, low, and bulk density seed.
If
a general-purpose drill like what is normally used to plant small grains or if
the seed is broadcast planted, it will be necessary to mix the seed with a
carrier or a disperser, such as a dry sand or a extremely low-Nitrogen
fertilizer blend (0-20-10 or 6-46-0) to flow the seed through the drill box.
Fertilizing New Seed
Normally,
1 pound of bulk seed will require 5 to 8 pounds of fertilizer. Avoid using a
medium to high nitrogen fertilizer since this will promote competition from
exotic, invasive weedy plants and suppress the establishment of beneficial
bacteria. Phosphorus and potassium are beneficial in promoting root growth and
quick establishment.
Soil Organic Matter
If
drilling into soils that have been previously abused with chemicals, or
extremely overgrazed, soil fauna may be dead or the soil-food-web out of
balance. In healthy prairies, organic matter content may exceed 3.5 % - up to
4.8%. The soil fauna will be aerobic-bacteria dominated, but still have a
healthy complement of fungi, particularly Mychorrizae fungi that form a mutually
beneficial relationship with a plant’s roots. A good way to inoculate your
seed prior to broadcasting or drilling is to mix the seed with an equal amount
of 1/8”-screened and dried compost. The compost quality is critical. It should
have been heated properly and remained aerobic in the process and allowed to sit
for a month or so after the final cool-down. Actinomycetes bacteria and
Mychorrizae fungi may be added for the final cool-down phase. After allowing the
seed-compost mix to sit overnight, mix with dry sand or fertilizer to help the
chaffy seed flow through the equipment. See
http://www.soilfoodweb.com/.
Using a
Drill Seeder
When
using a native grass drill, otherwise known as a rangeland drill, there are some
tips to follow to help insure success and one basic thought to keep in mind;
chaffy native grass seed does not behave like smooth-coated seeds, which flow
much easier. Although rangeland drills are designed to plant chaffy native
grasses, the "fuzz" and appendages of these seeds tend to stick and
adhere to everything.
Do
not plant too fast. The first impulse after the drill is set and calibrated is
to get done as fast as possible. Planting should be done at 3 to 5 MPH. The
fluffier the seed, the slower you go, and the more inert material in the seed,
the slower you need to go. Several problems occur if you go too fast. Seed
falling from the drop tube to the furrow hits the spinning coulter.
Native grass seed, being light and fluffy, is sent for a ride, perhaps
falling in furrow, perhaps not. It
is often the case where more seed falls outside the furrow rather than in,
resulting in a thin and scattered stand of seedlings.
-
Drilling too fast also bounces and packs the seed. In the worst possible case scenario, seed will pack so tightly that it ends up shearing a pin.
-
Check the planting depth. Drill forward 10 to 15 feet and check the planting depth. Make any adjustments and repeat the procedure if necessary. Remember, seed deeper than 1/2 inch will most probably be lost. Some seed on the surface is acceptable, actually preferable to being too deep.
-
Take the tractor up to planting speed and plant a few hundred feet. Stop, and then check the planting depth again. Seed placement will be different under actual planting conditions than at slow speeds and short pulls. The bouncing of the drill and the faster turning furrow openers will have an affect on planting depth. It is important to check planting depth under actual planting conditions.
-
Fill the seed boxes loosely, level to the top. Do not pack seed into the box to get that last little bit left in the bag. Packed seed will not flow through the drill the same, if at all, and calibration will not be accurate. You may also run the risk of packing seed so tight that it will shear a pin.
-
Check the level of seed in the seed box often. You don't want to waste your time pulling an empty drill. Stopping and checking also serves as a means to recheck calibration. Once you are calibrated you should be able to keep track of the time and get an idea of when you need to stop and refill. The drill holds X number of bags of seed, one bag plants Y acres and you are planting at a rate of Z acres an hour.
Keep the seed level above the agitator shaft. Drilling with less seed will result in inaccurate seeding rates.
During drilling, when the soil is too wet, the seed between the furrow openers will stick to the soil as it is pulled out of the ground as the coulters pull through and out of the soil. Some of the seed ends up on top of the ground but most of it ends up stuck to the out side of the coulters with all the mud.
One of the most common mistakes people make when drilling chaffy seeds is once the drill is calibrated and set, off they go never looking back to check the drill. An hour later when they stop to refill the seed box, lo and behold, one or more dividers in the seed box is still full. A clogged drop tube is usually the culprit.
A good rangeland drill will have a means to visually check to be sure
seed is flowing from the seed box through the drop tubes into the furrow
openers. Any chaffy seed you buy will have some small plant stems or other
debris, which could clog the drop tube. If you regularly check the openings in
the transitions, you will know immediately if a drop tube is plugged. Stop the
tractor and drill and unplug it. Many are tempted to just ignore it and go on,
particularly if it is just one-drop tube. Resist the temptation, as time goes on
the clog will only get worse and can become a nightmare to relieve.
While
looking back and checking, be sure to see that everything is working properly.
Sheared pins, chains off of sprockets, clutches engaged or any number of things
could be happening (or not happening) to keep your drill from working. The worst
thing you can do is spend several hours planting to discover you haven't planted
a thing.
Check
and recheck calibration. When calibrating, put enough seed into the seed box to
at least cover the auger shaft. If you use less seed the calibration may be
inaccurate. Repeat the calibration procedure several times to confirm your
results. Non-flowing native grasses do strange things. Check at least 3 times
after you think it is set. If you get similar results two of the three times
then consider it set but don't forget about it. Ground check your calibration.
You know that a 50 pound bag of seed will cover X number of acres. Put in one
bag, estimate X number of acres and check to see if you are still on track.
Hydro-Seeding & Seed hay
Hydro seeding, often called hydro mulching can be a successful method of
broadcasting native grasses and wildflower seed, but only if the mulch particles
are large and the consistency of the sprayed mix is quite liquid. Since
‘fuzzy’ seed tends to suspend in high-density, pulpy mulch, the seed
doesn’t actually make good soil contact, thus, lowering the amount of
germination and establishment. However,
large particles mulch can enhance establishment by retaining moisture in the
soil. Rain will wash the native seed around the largish stems and make adequate
soil contact.
Seed hay is simple hay cut from a prairie remnant. It contains a broad
range of grasses and forbs desired. Seed
hay
is a method of taking advantage of existing technology to gather desirable grass
and forb seed and mulch, along with a complement of wildflower seed. This method also diminishes any selective criteria on the
available genetic variance in a given locale.
The trick is to diminish the seed loss between the time the hay is cut
and baled. If cut too early, a lot
of the seed will not have set. If cut too late, much seed will be lost as the
stems dry prior to baling. The
cutter must not crimp the stems as they pass through the machine.
This will also cause much seed to shatter.
Also, the cut hay must not be raked too much, as this too will shatter
much seed. However, the hay must be totally dry prior to baling,
otherwise the moisture will start the bale to compost as it sits rolled up.
As the internal bale temperature reaches 140oF, the seed will
‘cook’ and be useless. So be
careful, timing, technique and attention is everything.
Standing vegetation
Successful plantings are made into standing vegetation. Seeds are broadcast planted in early spring and then treaded or trampled into the soil with a high density of grazing animals. Bison are ideal, but livestock (cattle, sheep, goats, and horses) will suffice. Animal hoof action will stir the soil and at the same time press the seed giving good seed soil contact. Good hoof action will require herd densities of 8 to 10 animals per acre for a given period. Also grazing at a high density of animals will help control weedy plants. Numerous successful plantings have been done using this technique.Burn-down herbicides
will stop the growth of all vegetation. This
practice is beneficial just before broadcast planting into existing weedy
vegetation. Using an herbicide will
make it illegal to harvest hay or graze for an extended period.
In small areas, black plastic is also very effective in killing weeds and
their seed. The soil must be very
wet prior to placing the plastic down to be effective.
The closer the plastic is to the ground, the better this method works.
In effect, the seed and plants at the soil surface are “steamed”.
Allow the plastic to remain in place for six weeks during the heat of
summer.
Stubble Crop or Dead Litter Crop
Getting
stands established in low rainfall areas can be a problem, There is not enough
cover to protect the soil from wind erosion and hold the necessary surface
moisture for good germination and seedling survival. A common practice to
overcome this problem is to grow an annual crop of Sudan, millet wheat or cereal
rye on a prepared seedbed the year before. This is called a stubble crop or dead
litter crop. Then let plant residue accumulate on the soil surface at the end of
the growing season. Combining, haying or partial grazing can control the amount
of residue. At frost time, you would want the soil to cover with enough litter
to prevent winter weeds from growing. In early spring, broadcast seed over the
litter. Rainfall will wash the seed beneath the litter.
Or drill between the stubble rows.
Seedballs
Seedballs were first invented by Masanobu Fukuoka in Japan after WWII.
Popularized by Jim Bones in the late 1990’s, seedballs have proven to be an
effective technique in areas that are too large to use hand equipment (rakes,
etc.) and too small for tractor equipment, such as drills, etc. They have also
proven to be successful on slopped or rocky areas that are common in the Texas
Hill Country. Or when inter-seeding new species into prior planted areas. The clay pellet, approximately 3/8” to ½” in diameter
should contain all the complement of species you want to broadcast on the
restoration site. Compost and any other amendments can be added prior to
rolling. A typical recipe calls for the following:
Seed:
1-2 parts
Compost: 2-3 parts
Sand
½-1 parts
Clay:
4-6 parts
Water:
Very little, as needed.
Mix seed and compost well, to inoculate the seed with the
beneficial bacteria in the compost. Then
add sand, amendments, and clay. Mix
well again. Add a little water at a
time, while mixing the vat. The
final consistency should be that of peanut butter.
Pinch off small amounts and roll into balls in the palms of your hands,
until you feel it get hard. Throw the seedball on to a tarp or raised screen to
dry. Only mix-up an amount that you
will finish rolling within an hour or two.
Keep working a little at a time. Once
the seedballs are dry, throw out by hand at the restoration site.
The clay will protect the precious seed until rain arrives, then the
seedball will melt and the seed will germinate.
The clay will also keep the seed in place if the rain turns into a
‘gully-washer’.
To step-up production beyond hand rolling, try the “Van-Bachmeyer”
drum, which is a 55 gal. drum, laying horizontal on a portable stand, which is
driven by an electric or gasoline motor. This
method is capable of producing up to 110-150 lbs. per day. Of seedballs per day, enough to cover an acre at a rate of 1
seedball per square foot, or 10-20 lbs. PLS seed/ac.
Higher production rates may be accomplished using a “pan-roller”,
which is an industrial grade piece of equipment designed to handle ore for the
mining trades.
As in any other planting, make sure to suppress the weeds and/or
eradicate the exotic invasive species prior to broadcasting the seedballs.
Transplants
Other
planting techniques may involve transplanting plugs of live plants. This method
is very successful, particularly when salvaging plants from development sites,
but labor intensive and not economical on large areas. Plugs are commonly used
for small plot areas of a 1000 sq. ft or less to establish a prairie garden or
eroded sites where it is difficult to get stands. Seed companies will also take
nodes of live plants placed in containers, start plants growing in a green house
for transplanting. Plants should be spaced at 18 to 20 inches apart with soil
firmly packed and watered in.
FERTILIZATION VS.
PRODUCTIVITY
It is important to take a soil test
before planting any seed. Look at micro (or trace elements) as well as the macro
elements (NPK). Proper and available Calcium amounts and the
Native grasses will not respond to nitrogen fertilization. Nitrate
nitrogen can be a detriment in getting good stands in that it will promote
competition from weeds and other undesirable plants. Excessive nitrate nitrogen can effect soil microbes and limit
the development of the proper food web for Native grass plants to grow.
A microbe or soil faunal assay is also very helpful in determining the
health of your soil. This is
because, bacteria in particular, are the temporary holders of available nitrogen
in the system, that when eaten by protozoa, becomes immediately available to the
plant roots. Otherwise, the
nitrogen, as is very mobile, would be washed out of the soil and end up in
creeks and rivers after each rain event. The
assay will also tell you if root-eating nematodes have reached critical levels. The “take-home” message here is if you properly feed your
soil, and grow healthy populations of beneficial microbes, they will grow the
desirable native prairie plants for you.
WEED CONTROL
Weeds are those low successional plants
that tend to dominate in prepared seedbeds, often of Eurasian origin.
They must be controlled or suppressed until native plants are well
established. Control methods may consist of mowing, grazing, hoeing or the use
of selective herbicides. It is recommended that particularly invasive species such as
Johnsongrass (Sorghum halapense), KR bluestem (Bothriochloa
ischaemum), and Bermuda grass (Cynodon dactylon) be completely eliminated before
restoration attempts are started.
Seedling grass plants do not get very large the first year. Mowing at 4
to 6 inches in plant height will help hold back weedy plants. You may need to
mow several times over the course of the growing season. Avoid any mowing in the
fall as grass plants may be getting enough height that the mower could affect
them. Plants need to make necessary top growth in the fall in order to store
root reserves for winter survival.
If weeds have completely overgrown your new seedlings before you've
gotten a chance to mow, it may be better to not mow at all. The foremost
concern, particularly a problem with rotary mowers, is the accumulation of
litter in windrows. The thick mat of dead vegetation caused by a rotary mower
will choke out and kill any new seedlings eliminating any chance of
establishment, whereas the new seedlings stand somewhat of a chance without
mowing. As long as they are alive, they at least have a chance of making it.
Native grasses also, under heavy, tall weed pressure, respond by growing as tall
as necessary to compete, thereby being susceptible to clipping when the weeds
are mowed. A good example is when foxtail becomes a problem and grows 3 feet or
taller, native grass seedlings, though very spindly will grow 18 inches to 2
feet tall with all leaf area above 18 inches. When mowed at 12 inches a sequence
of negative reactions begin. Because of their tall spindly growth their leaves
get clipped off leaving nothing but the stem causing the plant to pull growth
energy from the roots that haven't had a chance to store any carbohydrates yet,
weakening the plant, further reducing it's chance of survival. I've also seen
new seedlings, exposed by a recent mowing scalded by the hot August sun, killing
them.
Herbicides can be effective in some
cases. When planting grasses exclusively, a broad-leaved herbicide such as 2,4-D
can be used to control weeds. The problem is that most broadleaf herbicides do
not carry a label for use on native grasses. In that case the user assumes all
risks. Consult with your local Ag-chem dealer for recommendation of rates and
chemical control methods. Also licensing by Texas Department of agriculture may
be necessary.
Mowing may not be applicable or economically feasible on a large acreage.
Grazing at a high stock density to flash graze an area will suppress weedy
plants. Most weeds are palatable to grazing livestock when they are small and
succulent in early spring. Weeds have shallow root systems and can be overcome
with grazing pressure. Sheep and goats prefer weeds over grasses and will
selective graze them. An additional benefit to flash grazing is that the high
concentration of animals for a short while will consequently cause a nice,
concentrated odor plum that dung beetles will smell for miles and come flying
in. Research has shown that dung
beetles can bury over a ton of manure per acre per day.
Not only does this fertilize and increase the productivity of the soil,
by feeding the microbes with organic matter, but it circumvents the blow-fly
life-cycle that can transmit animal disease.
Increased aeration and water-holding capacity also occurs as a
by-product, that in turn helps the health and productivity of the native plant
community.
MAINTENANCE
It will take 2 to 3 years for native
grass plants to become established. After
they become mature and produce seed, plants will require very little
maintenance. It is best if they are
rotationally grazed. Grass plants
by nature are meant to be bitten and harvested by grazing animals.
Grazing will force plants to produce lateral shoots creating new plants.
If left un-grazed, the accumulation of residue in time will began to
smoother and choke plants limiting their survival and capping will prevent, and
preventing new plants from germinating. Rotationally
grazing is the best method to prevent the accumulation of residue.
Plants respond to rest between grazing periods. Plant material is cycled
through the animals and returned to the soil as organic matter. Dung beetles
will move in and do what they do best.
Mowing and controlled fire are methods of removing old prairie
thatch. In natural prairie ecosystems, fire not only gets rid of accumulated
thatch, it also helps reduce woody plant invasion and stimulates the growth of
many native grasses and wildflowers. Timing of burns and the choice of a cool
burn versus a hot burn will have different effects on species composition.
Historically, burns occurred with frequent regularity in Texas, usually
in the summer time. Keep in mind that a controlled burn is not only a useful
maintenance tool, but also a necessary tool since the prairie plant community
evolved under a periodic fire and grazing regime. To remove or suppress the
presence of fire and grazing is tantamount to hindering the very forces that
make prairies what they are. Please be advised that conducting a safe controlled
burn requires some expertise and planning. Be certain to check local regulations and permit procedures.
When burning, plan well in advance, have all the necessary equipment,
have adequate assistance, and always use caution.
But do it.