Native
And
Prairie Restoration
Site-Preparation And Seeding Information Sheet
Prepared
by Lynda Boyer
Restoration
Biologist and Native Seed Manager
Heritage
Seedlings Inc.
www.heritageseedlings.com
September
29, 2004 (updated August 26, 2005)
Note: These are
techniques that I, personally, have tried. For a full list of a variety of site
prep and seedling techniques, please see the first reference at the end under
“Additional Resources” in Appendix A.
1) Remnant prairie with a good native
component
2) Meadow with a good native component
3) Meadow with only a few natives
4) Uncultivated old fields and pasture with
no natives
5) Cultivated agricultural field
6) Highly disturbed
(excavation, logging etc)
7) Steep areas
where erosion is a concern
(1 or 2)You
need to tiptoe around the natives and only use herbicide in weedy areas with
few or no natives. These areas can be planted with plugs of native plants in
the fall, or seeded if the area is free of major weeds. In the native rich
areas, you can spot-spray weeds or use mechanical control methods such as
weed-eaters, pruners or hand-pulling.
(3) You must decide if it's OK to lose the few
native species you have and then try to reestablish them from seed. For
example, many of our old fields have yarrow and buttercup but little else;
since these species are commercially available, you can focus your efforts on
preparing a site substantially reduced of weeds, and re-seed them.
(4 and 5) Use
herbicide (glyphosate) for AT LEAST two seasons to kill existing vegetation. This
should be applied as soon as you can get into the site. Suggested rate is 1 – 1.5%
glyphosate and 0.25-0.5% surfactant. Herbicide should be applied fall, early
spring, summer, and fall at a MINIMUM. Please, no tilling! Many grasses will be killed in one season;
however, many of our deep-rooted or rhizomatous forbs such as Queen Anne’s
lace, perennial vetch, St. John’s-wort, and clover take more than one season to
control. In addition, hard-seeded species
and annuals such as crane’s bill, mustard, and speedwell will take advantage of
the newly opened space and become flush the second season. Timing of the herbicide application is
crucial. It is desirable to eliminate
each suite of weeds prior to flowering.
Note: Cultivation is not necessary in the age of
no-till drills. Tilling only brings weed seed continually to the surface and
you will NEVER, EVER, EVER, exhaust the weed seed that has built up in the soil
for generations.
A recent
Restoration site-preparation forum hosted by the Lane Council of Governments
and attended by restorationists, researchers, water and soil scientists, and
farmers concluded that the best way to prepare a pasture or agricultural field
for native prairie seed reintroduction is herbicide application for at least two
years without cultivation. Or, if you must till, do it ONLY ONCE and
start the herbicide regime. If baresoil is a concern, plant a cereal cover crop
such as wheat, oats, or barley in September to control erosion and suppress
weeds. According to The Oregon State
Extension Service (see Appendix A Below) cover crops “protect the soil surface,
smother weeds, ….and scavenge nitrogen from the soil before it is leached below
the root zone by winter rains”.
It is important
to look at each site realistically and realize the weed seed bank is bigger
than you are and that it will never be exhausted. The seed drill will invariably dredge up weed
seed no matter how “clean” it may seem post-herbicide application. In uncultivated old fields and pasture,
aggressive, non-native grasses such as bentgrass, tall oatgrass, and
velvetgrass can be the long-term competitive issue for successful native plant
reestablishment. In cultivated fields,
the long-term issue is often broadleaf weeds.
(See Seeding Options below for herbicide strategies depending on
existing vegetation).
Many native
species (both grasses and forbs) are very slow to establish. They need a site
free of other vegetation in order to germinate unimpeded and to mature. Most
bunchgrasses and perennial forbs grow slowly and don't set seed until their
second season (some forbs not until the third.) They are also poor competitors.
Once the prairie is established, it is critically important to burn the site
every 3 – 5 years. If you can't burn, mow. Burning, however, is the most
effective tool to maintain native prairie. Willamette Valley Prairie species
evolved with fire. Fire reduces the competition from thatch and woody species
and stimulates the root crowns of the native grasses and forbs. Burning may
also discourage the non-native grasses and forbs that did not evolve with
fire. Burning every year is not
recommended because it increases the abundance of weedy annual species and
noxious thistles. It may also be necessary to continually augment the area with
new native seed and/or plants after burning or mowing to try and tip the
balance to a sustainable native stand.
During the
first growing season, it may be necessary to spot treating noxious weeds with
herbicide or hand-pulling. It is more
advantageous to target perennial broadleaf weeds such as
(6) If the
site has been disturbed by earthmoving it is absolutely essential to not let it
lay fallow during the winter. Both erosion concerns and the tendency of weeds
to occupy bare soil emphasize the need to sow something on the site as
soon as possible. If the desire is to re-vegetate the site with native plant
species, try to allow any weed seeds that might be present to germinate and
then spray them with glyphosate. Species to be sown should be fall and/or
winter germinating grasses and forbs that compete well with non-native species.
This ensures that they 1) establish prior to erosion problems; 2) they occupy
the spot before fall and winter weeds establish; and 3) they can compete with
any non-native species that may still be present on the site. For suggested
species, see option 3 below.
(7) Since native species are extremely small, even
those that germinate in the fall or winter, it might be advantageous on
erodable sites to first sow a nurse crop of a spring cereal grain. Sow the spring grain early so it will winter
kill, then oversow the area in October with the native seed crop. The native grasses sown should only be low
bunchgrasses that do not flower the first year (Roemer’s fescue, Koeleria
macrantha, Poa secunda, Danthonia californica) so the barley can
be mowed at a height of 6-8 inches. The
grain can be drilled at a moderate rate and, perhaps, on wider spacing than the
native seed. This should ensure little
competition from the nurse crop. Barley
has been recommended due to its lack of regrowth if mowed. This would be necessary if the barley does
not winter kill. Mowing when the barley
is just starting to flower will also reduce the chance of regrowth.
If the site is clean of
weedy forbs but non-native grasses are still a problem (common in old fields,
meadows, and pasture), seed native forbs only the first year, then overseed
with native grasses. This will allow
additional growing seasons where grass-specific herbicides such as Poast® or
Envoy® can be applied.
After the first stand
is established, burning or mowing the site prior to the second native seed application
is a good method for opening up the site.
For drilled seed, the suggested sowing rate is 7 – 9 lbs/acre for grasses
and 4-5 lbs/acre for forbs. For seed that is broadcasted or hydroseeded this
rate should be doubled (this allows for seed predation, and loss due to
erosion, desiccation, and poor soil contact). Seed size should be taken into
consideration with higher rates used for large seeds and lower rates for small
seeds. Seed mixes can be calculated to take into account the seeds/lb of
species desired. Drill seed to a maximum
depth of ¼”. Mulching is not recommended for drilled seed due the necessity of
light for most native prairie species to germinate. For broadcast seed, light
mulch may be applied but it must be weed free!
wp = wet prairie; up = upland prairie; w = woodland
|
Species |
Annual
or Perennial |
Common
Name |
|
Grasses, Sedges, Rushes |
||
|
Carex
tumulicola (up) |
P |
Foothill
sedge |
|
Danthonia
californica (up, wp) |
P |
|
|
Deschampsia
cespitosa (wp) |
P |
Tufted
hairgrass |
|
Elymus
glaucus (up, wp) |
P |
Blue
wildrye |
|
Elymus
trachycaulus (Agropyron caninum) (up) |
P |
Slender
wheatgrass |
|
Festuca
californica (w, up) |
P |
|
|
Festuca
roemeri (up) |
P |
Roemer’s
fescue |
|
Juncus
tenuis (wp) |
P |
Slender
rush |
|
Koeleria
macrantha (up) |
P |
Srairie
junegrass |
|
Luzula comosa (L. campestris) (up) |
P |
Woodrush |
|
Poa secunda (P. scabrella) (up, wp) |
P |
Pine
bluegrass |
|
Forbs |
||
|
Achillea
millefolium (up, wp) |
P |
Yarrow |
|
Agoseris
grandiflora (up) |
P |
Large-flowered
agoseris |
|
Allium
amplectens (wp) |
P |
Slim-leaf
onion |
|
Allium
accuminatum |
P |
Taper-tip
onion |
|
Aquilegia
|
P |
Columbine |
|
Asclepia
speciosus (up, wp) |
P |
Showy
milkweed |
|
Aster
hallii (up, wp) |
P |
Hall's
aster |
|
Aster
subspicatus (w) |
P |
|
|
Balsamorhiza
deltoidea |
P |
Balsamroot |
|
Brodieae
coronaria (up, wp) |
P |
Harvest
brodieae |
|
Calochortus
tolmiei |
P |
Cat’s
ears |
|
Camassia
leichtlinii (up, wp) |
P |
Leichtlin's
camas |
|
Cammasia
quamash (wp) |
P |
Common
cammas |
|
Castilleja
tenuis (Orthocarpus hispidis) (wp) |
A |
Hairy Owl
clover |
|
Clarkia
amoena (up, wp) |
A |
Farewell
to spring |
|
Clarkia
purpurea ssp purpurea (up) |
A |
Purple
godetia |
|
Clarkia
rhomboidea (up) |
A |
Rhombic-petaled
clarkia |
|
Collinsia
grandiflora (up, wp) |
A |
Large-flowered
blue-eyed mary |
|
Collomia
grandiflora (up) |
A |
Large-flowered
collomia |
|
Delphinium
menziesii (up) |
P |
Menzie’s
larkspur |
|
Delphinium
oreganum (up) |
P |
|
|
Dichelostemma
congestum (Brodieae
congesta) (up) |
P |
Ookow |
|
Dodecatheon
hendersonii (up, w) |
P |
Broad-leaved
shooting star |
|
Dodecatheon
pulchellum (wp) |
P |
Few-flowered
shooting star |
|
Eriophyllum
lanatum (up, wp) |
P |
|
|
Erythronium
oregonum (up) |
P |
Fawn lily |
|
Geranium
oreganum (up) |
P |
|
|
Gilia
capitata (up) |
A |
Blue
field gilia |
|
Iris
tenax (up) |
P |
|
|
Ligusticum
apiifolium (up) |
P |
Licorice
root |
|
Lomatium
dissectum (up) |
P |
Fern-leaved
lomatium/biscuit root |
|
Lomatium
nudicale (up) |
P |
Bare stem
lomatium/biscuit root |
|
Lomatium
utriculatum (up) |
P |
Spring
gold |
|
Lotus
micranthus (up) |
A |
Small-flowered
deervetch |
|
Lotus
unifoliolatus (L.
purshianus) (up, wp) |
A |
Spanish clover |
|
Lupinus
albicaulis (up) |
P |
Sickle-keeled
lupine |
|
Lupinus
bicolor (up) |
A |
Small-flowered
lupine |
|
Lupinus
polyphyllus (wp) |
P |
Large-leaf
lupine |
|
Madia
elegans (up) |
A |
Showy
tarweed |
|
Madia
gracilis (up) |
A |
Common / grassy
tarweed |
|
Perideridia
oregana or P.
gairdneri (up, wp) |
P |
Yampah |
|
Potentilla
glandulosa (up) |
P |
Slicky
cinqufoil |
|
Potentilla
gracilis (up, wp) |
P |
|
|
Prunella vulgaris var. lanceolata (up, wp) |
P |
Self-heal |
|
Psoralea
physodes (up) |
P |
Scurf pea |
|
Ranunculus
occidentalis (up) |
P |
Western
buttercup |
|
Sanguisorba
occidentalis (up, wp) |
A |
Western
burnet |
|
Sanicula
bipinnatifida (up) |
P |
Purple
sancicle |
|
Sidalcea
campestris (up) |
P |
Meadow
checker mallow |
|
Sidalcea malviflora ssp. virgata (up) |
P |
Rose
checker mallow |
|
Silene
hookerii (up) |
P |
Hooker’s
silene |
|
Sisyrinchium
angustifolium (wp) |
P |
Blue-eyed
grass |
|
Spiranthes
romanzoffiana (up, wp) |
P |
Ladies’ tresses |
|
Trifolium
tridentatum (up) |
A |
Tomcat
clover |
|
Triteleia
hyacinthina (Brodieae
hyacinthina) (up, wp) |
P |
Hyacinth
brodieae |
|
Vicia |
P |
American
vetch |
|
Viola
adunca (up) |
P |
Early
blue violet |
|
Viola nuttallii var. praemorsa (up) |
P |
Yellow
prairie violet |
|
Wyethia
angustifolia (up) |
P |
Mule’s
ear |
|
Zigadenus
venenosus (up, wp) |
P |
Death
camas |
1)
Mature
oak woodland with conifers over-topping the oaks and young conifer and oak in
the understory
2)
Young
oak in very thick stands
3)
Invasive
shrubs
4)
Bare-ground
after tree and shrub removal
5)
Canadian
thistle, knapweed, and biennial thistle infestations
6)
Oak
savanna (grassland with large, open-growth oaks spaced 2-5 trees/acre)
7) No/Few Oak
(1) Remove conifers by hand-cutting. Conifers that would harm oaks if felled can be limbed and topped to provide wildlife habitat. Also, some conifers can be partially limbed and left for replacement snags. Young, skinny oaks with no lower branches should be thinned. Retain any oaks that are in more open habitat and have developed lower branches. Woodland target density should be approximately 40 – 50 trees/acre.
Table 2 – Suggested Understory Vegetation for Oak
|
Species |
Annual or Perennial |
Common Name |
|
Grasses & Sedges |
||
|
Bromus sitchensis |
P |
|
|
Bromus vulgaris |
P |
|
|
Carex deweyana |
P |
Dewey’s sedge |
|
Elymus glaucus |
P |
Blue wildrye |
|
Festuca californica |
P |
|
|
Forbs |
||
|
Aquilegia |
P |
Columbine |
|
Camassia leichlinii |
P |
Tall camas |
|
Erythronium oregonum |
P |
Fawn lily |
|
Geum macrophyllum |
P |
Large-leaved avens |
|
Iris tenax |
P |
|
|
Ligusticum apiifolium |
P |
Licorice root |
|
Lomatium dissectum |
P |
Fern-leaved lomatium |
|
Osmorhiza chilensis |
P |
Sweet cicely |
|
Prunella vulgaris ssp.
lanceolata |
P |
Self-heal |
|
Rupertia physodes
(Psoralea p) |
P |
Scurf pea |
|
Sidalcea campestris |
P |
Meadow checkmallow |
|
Tellima grandiflora |
P |
Fringe cup |
|
Small Trees & Shrubs |
||
|
Amelanchier alnifolia |
P |
Serviceberry |
|
Corylus cornuta (var
californica) |
P |
Western hazelnut |
|
Holodiscus discolor |
P |
Ocean spray |
|
Mahonia (berberis)
aquifolium |
P |
Oregon grape |
|
Oemleria cerasiformis |
P |
Oso berry or Indian plum |
|
Ribes sanguineum |
P |
Red-flowering current |
|
|
P |
Baldhip rose |
|
Symphoricarpos albus |
P |
White snowberry |
(2) Remove the majority of the
oaks so that grassland can be reestablished or enhanced. Retain oaks with lower
branches and remove the others. The trees with lower branches will be able to
mature into open-grown oaks with large crowns.
These large branches will contain numerous microhabitats, will become
draped with nutritious lichens, and produce abundant acorns. Target density
should be 2 – 5 trees/acre. Hand-cutting
is one option but there are low-impact (rubber-tracked) skid-steers available
that can mechanically remove the trees and apply herbicide to the stump (oaks
resprout). Since it is desirable to re-seed immediately after exposing
bare soil (see #4 below), logging should be done just before spring rains stop
or fall rains begin.
(3) Mow or hand-cut invasive
shrubs such as Himalayan and evergreen blackberry, poison-oak (native but can become
noxious if not controlled), Scotchbroom, English hawthorn, holly, and
sweetbriar rose. Many rubber-tracked skid-steers have brushing mowers that can
handle large areas of tall brush. Hawthorn will re-sprout so application
of herbicide to the freshly cut stump is imperative. Poison oak and English ivy
climbing trees can be cut from the trees using handsaws or a heavy jabbing tool
with a sharp blade at the end to cut the weed’s roots near the base of the
tree. English ivy growing on the ground can be hand-pulled or cut. However, it
roots at the nodes so must be put onto plastic to dry and die. For long-term
maintenance and control of brush, see #4 below.
(4) Bare soil is an open
invitation to weeds (especially thistles) so it must be immediately
seeded with aggressive native grasses such as Elymus trachycaulus and Elymus
glaucus. They will germinate readily if sown while there is rain. This will
also reestablish native grassland in these areas and allow for long-term shrub
control by periodic fire. After seeding the grass, the broad-leaf weeds can be
spot-sprayed until under control. Allow two years before burning the grasses to
ensure hardiness of the crown. If burning is not an option, mowing is the best
alternative. If the area is clean of invasive broadleaf species, sow native
forbs after the burning or mowing treatment.
Note: Both of these grass species germinate really well on the residue
left after a brush pile has been burned and ensure that weeds to not overtake
the bare ground.
(5) Canadian thistle and knapweed
are rhizomatous perennials and must not be pulled or tilled as a weed
control method. The most effective method of control is to spot-spray the
rosettes with a composite-specific herbicide (containing clopyralid) very early
in the spring before the grass becomes too tall. Note: herbicides with clopyralid are
long-lived in soil and compost so the chemical should only be applied to
the target plant. Biennial thistles (bull, Italian, milk) can be treated with
glyphosate in the rosette stage. If they are in the early flowering stage, it
is best to treat them early with a general broadleaf herbicide, which will kill
the plants more quickly, and before seed set.
(6) Work to improve the grassland
for ground nesting species (see Conservation Strategy for Landbirds in Lowlands and Valleys
of Western Oregon and Washington listed in Suggested References and the Grassland Section
above). Retain some smaller
oaks as replacement trees.
Note: Retain or plant
some native shrubs where appropriate (ravines or around mature trees). Good
wildlife shrub species are: Amelanchier
alnifolia, Rhamnus purshianus,
and Holodiscus bicolor. Non-native
shrubs such as Himalayan /evergreen blackberry, English hawthorn, and scotch
broom should be removed. Again, there are low-impact skid-steers available that
can mow these species down. Re-growth of blackberry can be spot-sprayed with
glyphosate in October. Spot spraying for three years has proven very effective.
Regular maintenance of the site by burning or mowing should keep the shrubs in
control.
(7) If you want to plant oak on
your site AND want native grassland habitat, establish the prairie first (see
above for suggested methods). When the grassland is established (in 2 – 3
years), mow or burn the site in the fall and plant oaks in clusters of 4 – 5
trees. Plant the clusters at a savanna density (2 – 5 clusters/acre). Oaks (and
other native trees and shrubs) establish best when planted in the winter. Spring
is often iffy due to unpredictable rainfall. When the oaks are 5-10 years old, the
clusters can be thinned to ensure open-growth oaks are established at a savanna
density.
APPENDIX A
Suggested Additional Resources
Ø
Techniques
for Restoring Native Plant Communities in
http://www.ci.eugene.or.us/parks/wetlands/pdfs/EPA-WhitePaperFinal.pdf
Ø
Native
Seed Network http:www.nativeseednetwork.org
Ø OSU Professor of Botany, Mark Wilson http://www.onid.orst.edu/~wilsomar/Index.htm
Ø The
Institute for Applied Ecology http://www.appliedeco.org/
Ø Conservation Strategy for Landbirds in
Lowlands and Valleys of Western Oregon and
http://community.gorge.net/natres/pif/con_plans/west_low/west_low_plan.html
Ø Restoring Rare Native Habitats in the
http://www.biodiversitypartners.org/pubs/index.shtml
Ø A Landowner’s Guide for Restoring and
Managing
Ø
Landowner Video Guide for
Restoring and Managing Oregon White Oak Habitats (65 min) On-the ground coverage of
habitat conditions, management opportunities, restoration projects, common
landowner goals, controlling invasive species, etc. by Hugh Snook, BLM, and Barry Schreiber, Flora & Fauna Video
Production. Available free at www.OR.BLM.gov/Salem
Ø
R-J Consulting Services, LLC
(contract brush and tree removal with low-impact skid steer). 541-967-9550 (home) 541-979-7282 (cell) mailto:rowen2378@juno.com
Ø Integrated Resource Management (contract brush and tree removal
with low-impact skid steer and grant writing). 541-484-1217
mailto:darin@irmforestry.com
Ø USFW Partners for Fish and Wildlife Program http://partners.fws.gov/, Steve Smith,
Ø ODFW Landowners Incentive Program http://www.dfw.state.or.us/test/LIP/overview.html,
Bruce Campbell, Willamette Valley Administrator 503-947-6099 mailto:Bruce.H.Campbell@DFW.STATE.OR.US
Ø OSU Extension Service, Private Landowner Workshops
For Conservation and Restoration of Native Woodlands. Brad Withrow-Robinson
503-434-7517 brad.w-r@oregonstate.edu
Ø Cereal Grains as Cover Crops. OSU Extension Service http://eesc.orst.edu/agcomwebfile/edmat/html/EM/EM8692/EM8692.html
APPENDIX B
Target Chemicals for Weed Control
Seed Production and
Restorations
Lots of Info on Web – Here are some I have
found helpful
http://www.greensmiths.com/herbicides.htm
Overview of some
chemicals for specific weeds
http://www.ipaw.org/herbicides.htm
http://grounds-mag.com/mag/grounds_maintenance_new_pest_controls/
Note this site
says Envoy effective on perennial grasses! I found this to be true
http://grounds-mag.com/mag/grounds_maintenance_understand_mode_action/
How they work
http://stephenville.tamu.edu/~butler/foragesoftexas/weedcontrol/hermode.pdf
http://www.utextension.utk.edu/publications/pbfiles/PB1728_sec2.pdf
http://www.maltawildplants.com/ASTR/Docs/CNZBO/Weedchart.pdf
Weeds
susceptible to various herbicides
My Experience
Note: Broadleaf
(dicots) chemicals are safe for monocots (grasses, sedges, rushes, lilies,
iris) EXCEPT WHEN FLOWERING (contorts seed heads and lowers yields)
Ø
Glyphostate
[short lived in soil]
o
Everything!
[However, spraying post pollination, they will set seed]
o
Fall
applied to blackberry 3-5 years, effective control
Ø
Envoy
(grass-specific)
o
Works
on all wide-leaf grasses (even perennials)
o
Not on
annual fescue, and red fescue (skinny leaves)
o
Hit
while young and growing (ineffective in flower)
o
Safe
for non-grass monocots (lilies, iris, sedges, rushes)
Ø
2,4,-D
(broadleaf) [short-lived in soil]
o
Good
for: composites (thistles, dandelion ect), pearlwort, mustards, geraniums
o
Not
good for: clover, speedwell, chickweeds, miners lettuce, vetch
Ø
Mecoprop
“MCPP” (broadleaf) – Combined with MCPA and dicamba or MCPA and 2,4-DP [short
lived in soil]
o
Kills
pretty much everything (not very effective on vetch)!
o
Clover,
speedwell (MCPA), chickweeds, burdock, bedstraw!
o
Best
to target prior to pollination or seed-set may still take place.
Ø
Clopyralid
and Triclopyr [long-lived in soil]
o
Targets
are composites (especially Canadian thistle) and legumes (great on clover)
o
Spot-spray
ONLY