Brambles (genus Rubus) may be native but they are
generally undesirable in a prairie or savanna. This post is based on over 20
years of restoration work at Pleasant Valley Conservancy.
The story starts when Kathie
and I first started clearing invasive brush and trees from prairie and savanna
remnants at PVC in 1997. There was lots of bad stuff: shrubs such as buckthorn,
honeysuckle, and prickly ash and trees such as elm, cedar, red pine (planted),
box elder. If there were brambles, we did not notice them. Probably they were
shade-suppressed.
But once the site was opened
up, brambles started to flourish. Originally they were just small patches, which
in our ignorance we ignored. In 1999 some of these bramble patches were large
enough that we got rid of them. There may have been some larger patches, but in
a property as large as Pleasant Valley Conservancy, it was easy to overlook
them.
The Ecology of Brambles
Brambles are members of the
genus Rubus. They have perennial
roots systems but biennial tops. The roots continue to spread but new canes are
formed each year. The first year cane just grows vegetatively and in the second
year flowers and forms fruits. After fruit formation it dies. Thus, a bramble
patch is a mixture of first year and second year canes, as well as dead canes
which senesce.
We have three species of Rubus at PVC: blackberries, black
raspberries, red raspberries. All are bad, and we do not distinguish between
them, although red raspberries presents a special challenge.
The First Survey
It was 2005 before brambles
started to be so obvious that we could not ignore them. That year I made a
survey, marking each patch with a numbered stake. There were 17 patches, all in
open savannas. My notes in the table here give some idea of how large these bramble
patches were.
Data from June 5-6 2005
|
Stake #
|
Unit #
|
Location
|
Notes
|
|
1
|
12A
|
~75 ft below the upper road (below Toby’s); large patch in
flower
|
White Oak Savanna
|
|
2
|
12A
|
~75 ft farther down the hill from #1; edge of Unit 12E;
large patch in flower
|
White Oak Savanna
|
|
3
|
12A
|
Smaller patch but taller stems west of #1
|
White Oak Savanna
|
|
4
|
12C
|
Large patch among two large dead oaks; also outliers east
and downhill
|
White Oak Savanna
|
|
5
|
12C
|
About 75 ft east of trail down; along a drainage; follow
the drainage up and down
|
White Oak Savanna
|
|
6
|
11A
|
Edge of open area and edge of ridge; shorter plants but
lots; forming berries
|
Bur Oak Savanna
|
|
7
|
11A
|
Near road; low but lots forming berries
|
Bur Oak Savanna
|
|
8
|
11A
|
50 fit West of #7 near fallen oak
|
Bur Oak Savanna
|
|
9
|
13B
|
Lots of 1st year plants mixed in with Geraniuum
etc. Can cut it all. Whole top of knoll, also
|
Woods near east property boundary
|
|
10
|
17
|
N of Toby’s in former aspen zone; scattered but large
patch; 1st year plants
|
Between Toby’s NE corner and woods
|
|
11
|
11B
|
Above Paul Ihm’s wood pile
|
Bur Oak Savanna
|
|
12
|
11A
|
SE corner of saddle; large patch with little good; mow up
hill and to the east also
|
Bur Oak Savanna
|
|
13
|
23
|
Large patch of low brambles; uphill to the west from the
saddle; do the whole patch
|
East-facing hill above Hickory Ravine
|
|
14
|
7
|
Very large patch uphill from Hickory Ravine; mow down hill
and to the east
|
|
|
15
|
6
|
Top of hill near fire break; 75 ft west of side road;
large patch of low brambles; mow down the hill and into the gully
|
|
|
16
|
10
|
Across the fire break from stake #15; big patch mixed in
with brush; cut it all and then treat the brush
|
Should have a second person with you for treating the cut
stumps
|
|
17
|
5C/5B
|
West of Unit 4 along and below the fire break on both
sides of the gully; huge area
|
This is a two-three person job!
|
Getting Serious
At that time the only
information I could find about how to eradicate brambles was: Mowing several times a year will reduce
their vigor.
Reducing vigor did not sound
like a promising method for eradication.
By the late fall of 2005
Kathie and I had decided that our goal should be to get rid of all brambles, as
well as other invasive brush that had sprung up in our restored areas. After
all, we had spent a lot of effort opening up these prairies and savanna. If we
did not get rid of all these new invaders, we could be back where we started.
An awful thought!
We experimented with several
different methods of herbicide application: foliar spraying the bramble patches
(low herbicide concentration); basal bark (high concentration, in oil); cut and
treat the cut stems (high concentration, either aqueous of in oil). We rejected
foliar spraying of the large patches because of the possible peripheral herbicide
damage. We tried basal bark, but application from a backpack sprayer was also “wasterful”
of herbicide, and because of the high concentration, there were bare zones
around the treated patches. We also tried a sponge method for basal bark, but
the thorns on the brambles tore the sponges to shreds.
Cut-and-treat method
We chose the “cut-and-treat”
method because only small amounts of herbicide would be used, and it could be
applied carefully by a spray bottle. Because of the extent of the infestations,
this was usually a four- to five-person job. One person operated the Stihl
brush cutter and the others followed along with spray bottles containing 50% glyphosate. Since we were working primarily in
the winter, when it was below freezing we diluted the glyphosate with
windshield washer fluid. Where there was a lot of buckthorn, we used Garlon 4
in oil, which presented no freezing problem in the winter. The “treaters”
fanned out behind the brush cutter and treated each cut stem.
A great advantage of this
method is that it could be done any time of year, and especially at times when
weed work, plant surveys, seed collecting, etc. could not be done. We worked
with a combination of hired employees and volunteers.
I ran some preliminary
versions of this method in late November 2005. We then set up a major effort on
the White Oak Savanna starting in early January 2006. Todd Shumate from Michler
& Brown ran the brush cutter and three or four “treaters” followed behind.
Todd cut every woody shrub in the savanna. Brambles constituted at least half of
the brush, but honeysuckle and prickly ash were substantial.
The brush cutter was equipped
with a saw blade. Todd ran the brush cutter until he ran out of gas (about 45
minutes per tank). He then sharpened the saw blade with a special Stihl file.
This kept the cut stems clean and flat so they could be treated properly. Cut
stems that were dead were not treated. (Living cut stems are green even in the
winter.)
The First Major Effort
The table gives an example of
this work for a five-acre white oak savanna. Finishing the whole unit took 9
days, working about 40 person hours per acre. Fortunately, January of 2006 was
surprisingly mild and snow-free. Often we were in shirt sleeves at noon.
Table shows brush cutting work on Unit 12A (the White Oak Savanna). Total area 5.3 acres
|
|
2-Feb-06
|
31-Jan-06
|
26-Jan-06
|
24-Jan-06
|
19-Jan-06
|
17-Jan-06
|
12-Jan-06
|
5-Jan-06
|
3-Jan-06
|
Totals
|
|
Todd
|
5.5
|
5.25
|
7
|
6.75
|
6.75
|
6.75
|
5.5
|
6.75
|
|
50.25
|
|
Susan
|
5.5
|
|
|
|
5.75
|
5.25
|
5.5
|
5.75
|
|
27.75
|
|
Elke
|
5.5
|
|
6
|
|
5.75
|
|
|
|
|
17.25
|
|
Tom
|
5.5
|
4.9
|
6
|
5.5
|
5.75
|
5.25
|
5.5
|
4
|
2
|
44.4
|
|
Kathie
|
5.5
|
4.9
|
6
|
5.5
|
5.75
|
5.25
|
5.5
|
5.75
|
2
|
46.15
|
|
Brian
|
2.25
|
|
|
|
4.25
|
|
|
2
|
|
8.5
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Final total
|
|
|
|
|
|
|
|
|
|
194.3
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Averages>>
|
36.7
|
hrs/acre
|
|
|
|
|
|
|
|
|
|
|
If assume $25/hr, acreage cost is
|
|
|
|
|
|
|
|
|
|
|
|
$917.50
|
|
|
|
|
|
|
|
|
|
|
|
Roughly $1000/acre
|
|
|
|
|
|
|
|
|
|
Extending the Effort (2006-2007)
Once the White Oak Savanna
work was completed, we extended the work to the rest of the areas where brush
and brambles were rampant. The table shows the 2006-2007 work (81 work days; 30
days in 2006 and 51 days in 2007.)
In 2007 I established winter
intern positions, and we had 3 (or 4) UW-Madison students working two days a
week starting in January and continuing until mid May.
|
Date
|
Unit
|
Notes
|
|
7
Feb 2006
|
18
|
Lots
of honeysuckle; brambles; prickly ash; walnut resprouts
|
|
9
Feb 2006
|
18
|
Lots
of honeysuckle; brambles; prickly ash; walnut resprouts
|
|
14
February 2006
|
18
|
Lots
of honeysuckle; brambles; prickly ash; walnut resprouts
|
|
21
Feb 2006
|
6
|
Mostly
honeys; small buckth; few brmbles; some dogwood
|
|
23
Feb 2006
|
2
below Diag Trail
|
Lots
honeys few buckth; fee brmbles
|
|
28
Feb 2006
|
12B
|
Mostly
brambles
|
|
2
Mar 2006
|
12B
|
|
|
7
Mar 2006
|
3
(around big bur oak)
|
Mostly
brambles
|
|
7
Mar 2006
|
19C
|
Buckth
mostly
|
|
10
Mar 2006
|
6/23
|
Lots
little buckth
|
|
11
Mar 2006
|
6/23
|
|
|
14
Mar 2006
|
11
|
Big
bramble; buckth; prickly ash
|
|
21
Mar 2006
|
11
|
|
|
23
Mar 2006
|
10
|
Lots
tiny buckth; brambles
|
|
28
Mar 2006
|
6
(east)
|
Honeys;
brambles; s umac
|
|
30
Mar 2006
|
19
|
|
|
17
Nov 2006
|
7
|
Lower
part and adjacent to 18; shrubs/brambles small honeys; cut & treat glypho
|
|
19
Nov 2006
|
7
|
small
honeys buckth brambles; few walnuts
|
|
21
Nov 2006
|
7
|
|
|
27
Nov 2006
|
|
Lots
of notes about cut & treat and then plant
|
|
30
Nov 2006
|
3/6
|
Gully
above big bur; lots brambles; some honeys; few buckth; grape
|
|
5
Dec 2006
|
6/9
|
Gully
between 6 & 9; see record for details of how we did it
|
|
12
Dec 2006
|
6/9
|
top
of gully; gray dogw
|
|
15
Dec 2006
|
6/9
|
Continue
from 12 Dec
|
|
17
Dec 2006
|
12A
|
Check
for brush/bramble problems; 9 areas listed; mostly brambles (all 3 spp)
|
|
19
Dec 2006
|
6/9
|
gully/brambles
|
|
26
Dec 2006
|
6
|
gully
below S fire break;
|
|
28
Dec 2006
|
6
|
Finish
unit 6
|
|
28
Dec 2006
|
3/9
|
above
gully
|
|
2
Jan 2007
|
5
|
Up
to fire break
|
|
2
Jan 2007
|
3
|
|
|
3
Jan 2007
|
4/9
|
Winter
interns; paint stick!
|
|
4
Jan 2007
|
3/4/9
|
lots
of honeys on Unit 9; walnuts; Autumn olive!
|
|
8
Jan 2007
|
19A
|
Top,
near Toby’s; Chris instead of Todd
|
|
9
Jan 2007
|
3/4/9
|
|
|
10
Jan 2007
|
3/5
|
gully
above diagonal trail
|
|
11
Jan 2007
|
5B/C
|
|
|
15
Jan 2007
|
20
|
near
Pocket Prairie; snowed 5 inches the day before; worked anyway
|
|
17
Jan 2007
|
20
|
Also
bur oak grove near chain
|
|
18
Jan 2007
|
20
|
Along
woods road; lots blackberry lots hazel elderberry
|
|
22
Jan 2007
|
20
|
|
|
24
Jan 2007
|
20
|
Finish
Unit 20
|
|
25
Jan 2007
|
21
|
snow
too deep move to top of hill
|
|
26
Jan 2007
|
20
|
|
|
29
Jan 2007
|
21
|
West
of Ridge Prairie
|
|
30
Jan 2007
|
|
too
cold, did not work
|
|
31
Jan 2007
|
21
|
snow
mostly gone
|
|
1
Feb 2007
|
21
|
Just
T & K
|
|
5
Feb 2007
|
|
Below
zero in morning; work cancelled all week
|
|
12
Feb 2007
|
12A
|
Lots
of dead buckth but some alive
|
|
13
Feb 2007
|
19E/11E
|
19E
too windy; moved to 11D
|
|
14
Feb 2007
|
11D
|
|
|
15
Feb 2007
|
11D
|
large
blackberry patch; Mid Savanna Trail
|
|
16
Feb 2007
|
11D
|
finished
this unit
|
|
19
Feb 2007
|
2
|
gully
above 2 bur oaks
|
|
20
Feb 2007
|
2/3
|
finish
gully up to fire break; lots sumac; some honeys; some buckth; rare bramble
|
|
21
Feb 2007
|
2
|
above
diagonal trail
|
|
22
Feb 2007
|
2
|
above
diagonal trail
|
|
26
Feb 2007
|
7
|
Lower
& middle on west side
|
|
27
Feb 007
|
7
|
Middle
& upper; around East Overlook rocks
|
|
28
Feb 2007
|
6/7
|
Up
from Hickory Ravine into Unit 6
|
|
2
Mar 2007
|
Ravine
|
Ravine
between 12A and 20B; lots of snow drifts!
|
|
5
Mar 2007
|
14
|
Corner
PV Rd & Cty F; snow deep!
|
|
5
Mar 2007
|
1
|
Less
snow; road cut for Unit 1
|
|
6
Mar 2007
|
5A
|
|
|
6
Mar 2007
|
20B
|
after
lunch finish 20B
|
|
7
Mar 2007
|
14
|
below
quarry
|
|
8
Mar 2007
|
5A
|
Up
to Ridge Trail
|
|
8
Mar 2007
|
6
|
Afer
lunch, 5A too sloppy, moved to 6 lower east around rocks, lots of honeys but
small
|
|
12
Mar 2007
|
5A
|
|
|
13
Mar 2007
|
5A
|
Above
Unit 1 and along Ridge Trail; FINISH WHOLE SOUTH SLOPE!!
|
|
13
Mar 2007
|
Quarry
|
After
lunch
|
|
14
Mar 2007
|
2/19
|
Finish
Unit 2; start Unit 19
|
|
15
Mar 2007
|
6
|
along
dolomite shelf
|
|
15
Mar 2007
|
19
|
|
|
20
Mar 2007
|
19D/E
|
|
|
22
March2007
|
19C/D
|
|
|
28
Mar 2007
|
20C/19D
|
Finish
20C
|
|
4
Apr 2007
|
19C
|
|
|
5
Apr 2007
|
19C
|
|
Fire and Brambles: Spraying Resprouts
Brambles are fairly fire
sensitive and are killed by a controlled burn.
 |
| Fire moving through a bramble patch in a savanna. All bramble stems are killed. |
Starting in 2008 we added
another method of bramble control: foliar
spraying of resprouts after the bramble canes had been killed by early
spring burns. The details of this method are covered in several Tom’s Blog
posts in 2008, 2009, and 2010.
Although this method is very effective,
it is limited to May or early June, when the resprouts are small enough to
spray without too much peripheral damage. To set up the spraying routine, I
created another bramble database. By then I had learned how to use ArcGIS. On 14 and 16 April 2009 I walked
the whole south side of PVC, recording the coordinates of each patch
After a burn, bramble patches
are fairly easy to spot, as the following photo shows.
 |
| Large bramble patch easily seen after a spring burn. Unit 11B; red raspberry patch |
 |
| Typical resprouts after the brambles have been top-killed by fire; Mid-May |
 |
| Spraying bramble resprouts about mid-May. Any other woody invasives such as buckthorn or honeysuckle are also sprayed. Often a crew of 4-5 would work on the same unit |
Table used to create an ArcGIS map of brambles. The date burned was used to determine which units to spray first.
|
Patch
|
Lat
|
Lon
|
Unit
|
Species
|
Date
burned
|
Priority
|
Notes
|
|
1
|
43.10559567
|
-89.80980858
|
Cabin
|
Blackberry
|
4/3/2009
|
1
|
Small
|
|
2
|
43.10625558
|
-89.81188151
|
Crane
|
Blackberry
|
4/3/2009
|
2
|
Moderate
|
|
3
|
43.10738856
|
-89.81244938
|
Crane
|
Blackberry
|
4/3/2009
|
6
|
Huge!
|
|
4
|
43.10493216
|
-89.80763666
|
Valley
|
Blackberry
|
4/3/2009
|
4
|
Large
in line
|
|
5
|
43.10473401
|
-89.80720634
|
Valley
|
Blackberry
|
4/3/2009
|
1
|
Small
|
|
6
|
43.10489771
|
-89.80679244
|
Unit
7
|
Red
raspberry
|
3/19/2009
|
4
|
Large-blackberry
+ red raspberry
|
|
7
|
43.106673
|
-89.80296275
|
Unit
12B
|
Black
raspberry
|
4/8/2009
|
2
|
Moderate
|
|
8
|
43.10670745
|
-89.80279796
|
Unit
12B
|
Black
raspberry
|
4/8/2009
|
2
|
Moderate
|
|
9
|
43.10649136
|
-89.8028195
|
Unit
12A
|
Red
raspberry
|
4/8/2009
|
3
|
Both
red and black raspberry
|
|
10
|
43.10642933
|
-89.80255279
|
Unit
12A
|
Red
raspberry
|
4/8/2009
|
6
|
Huge!--also
hazel
|
|
11
|
43.10747255
|
-89.80242924
|
Unit
19E
|
Black
raspberry
|
4/3/2009
|
3
|
Loose
patches scattered
|
|
12
|
43.10759794
|
-89.80236797
|
Unit
19E
|
Blackberry
|
4/3/2009
|
1
|
Small
plus burdock
|
|
13
|
43.10737649
|
-89.80267533
|
Unit
19E
|
Black
raspberry
|
4/3/2009
|
1
|
Small,
near road
|
|
14
|
43.10721648
|
-89.80272344
|
Unit
11B
|
Red
raspberry
|
4/8/2009
|
2
|
By
road, across from 19E, linear along road
|
|
15
|
43.10718882
|
-89.80436982
|
Unit
11B
|
Red
raspberry
|
4/8/2009
|
6
|
Very
large! Also clone S and W of AP1
|
|
16
|
43.10696955
|
-89.8050278
|
Unit
11B
|
Red
raspberry
|
4/8/2009
|
6
|
Very
large clone around stake AP2
|
|
17
|
43.10694985
|
-89.80539626
|
Unit
11A
|
Red
raspberry
|
4/8/2009
|
6
|
Very
large clone around stake AP3
|
|
18
|
43.10729401
|
-89.80591837
|
Unit
19C
|
Red
raspberry
|
4/8/2009
|
5
|
Large
clone near road
|
|
19
|
43.10664257
|
-89.80375467
|
Unit
11D
|
Blackberry
|
4/8/2009
|
2
|
100
feet W of Junction of the two trails
|
|
20
|
43.1063953
|
-89.80440527
|
Unit
11D
|
Red
raspberry
|
4/8/2009
|
5
|
In
middle of unit, large clone
|
|
21
|
43.10640126
|
-89.80471448
|
Unit
11D
|
Red
raspberry
|
4/8/2009
|
3
|
In
middle, farther toward gully than BR20
|
|
22
|
43.10649178
|
-89.80462773
|
Unit
11D
|
Red
raspberry
|
4/8/2009
|
1
|
25
ft S of Mid Sav Trail; Small clone
|
|
23
|
43.10664115
|
-89.80473007
|
Unit
11C
|
Red
raspberry
|
4/8/2009
|
1
|
Above
Mid Sav, near trail, near large hickory; small clone
|
|
24
|
43.10663964
|
-89.80479612
|
Unit
11C
|
Red
raspberry
|
4/8/2009
|
1
|
Small
clone, short stems, above Mid Sav
|
|
25
|
43.10649354
|
-89.80546198
|
Unit
11C
|
Blackberry
|
4/8/2009
|
3
|
Near
Mid Sav and just E of large white oak
|
|
26
|
43.10438147
|
-89.80366163
|
Unit
20
|
Black
raspberry
|
4/18/2009
|
6
|
By
woods road, very large clone
|
|
27
|
43.10416186
|
-89.80353146
|
Unit
21
|
Black
raspberry
|
4/18/2009
|
1
|
Fairly
small, near woods road
|
|
28
|
43.10581922
|
-89.79962222
|
Unit
13
|
Black
raspberry
|
4/8/2009
|
6
|
Top
of knoll, very large clone, also down all sides
|
|
29
|
43.10412599
|
-89.80182314
|
Unit
21
|
Black
raspberry
|
4/18/2009
|
1
|
At
S end of Ridge Prairie, smallclone
|
|
30
|
43.10433671
|
-89.801943
|
Unit
21
|
Black
raspberry
|
4/18/2009
|
3
|
West
of BR29, larger, fairly loose clone
|
|
31
|
43.10670761
|
-89.79977419
|
Unit
13
|
Black
raspberry
|
4/8/2009
|
5
|
N
side, down hill from knoll and near fire break separating Toby's N; very
large but loose
|
|
32
|
43.10691012
|
-89.79992732
|
Toby's
N aspen
|
Blackberry
|
4/18/2009
|
1
|
Near
fire break to Unit 13, small
|
|
33
|
43.10757849
|
-89.80411207
|
Unit
19D
|
Red
raspberry
|
4/8/2009
|
3
|
Middle
betw woods road and N fire break, med-sized clone
|
|
34
|
43.10703333
|
-89.80819951
|
Unit
10
|
Black
raspberry
|
4/8/2009
|
1
|
Near
road and bur oak #704,fairly small clone
|
|
35
|
43.10691431
|
-89.8089574
|
Unit
8
|
Black
raspberry
|
4/8/2009
|
1
|
Near
Parking, small clone near downed logs
|
|
36
|
43.1066963
|
-89.8089258
|
Unit
8
|
Black
raspberry
|
4/8/2009
|
6
|
Very
large loose clone; lower SE side of unit
|
|
37
|
43.10709964
|
-89.8086979
|
Unit
19B
|
Black
raspberry
|
4/8/2009
|
5
|
fairly
large, near end road and AP-8
|
|
38
|
43.10714708
|
-89.80853898
|
Unit
19B
|
Black
raspberry
|
4/8/2009
|
6
|
very
large, up from N fire break and E of AP-8
|
|
39
|
43.10716728
|
-89.80809876
|
Unit
19B
|
Red
raspberry
|
4/8/2009
|
1
|
small
clone by road
|
|
40
|
43.10708078
|
-89.80763918
|
Unit
19B
|
Red
raspberry
|
4/8/2009
|
6
|
very
large clones of all three spp., between woods road and N fire break--MAJOR
JOB
|
|
41
|
43.10713316
|
-89.80734958
|
Unit
19B
|
Black
raspberry
|
4/8/2009
|
5
|
Large
patch, about 1/2 did not burn
|
|
42
|
43.10599859
|
-89.80708379
|
Unit
23
|
Black
raspberry
|
3/19/2009
|
1
|
Near
saddle road; may have been sprayed?
|
|
43
|
43.10604746
|
-89.80672413
|
Unit
11A
|
Black
raspberry
|
4/8/2009
|
6
|
Up
from saddle road, E of AP stake, very large clones almost merging; runs NE/SW
along the edge of the ridge, about 15 ft E of AP stake
|
|
46
|
43.10588418
|
-89.8065357
|
Unit
11A
|
Black
raspberry
|
4/8/2009
|
2
|
Downhill
from BR43, right next to saddle road; smallish clone
|
|
47
|
43.10568452
|
-89.8063311
|
Unit
11A
|
Black
raspberry
|
4/8/2009
|
6
|
Very
large clone between saddle road and Mid Sav Trail; all day job for 1 person!!
|
|
48
|
43.1054303
|
-89.80646202
|
Unit
7
|
Red
raspberry
|
3/19/2009
|
5
|
Below
saddle road;large scattered loose; from Hickory Ravine to rock outcrop
|
|
49
|
43.10424141
|
-89.80488572
|
Valley
|
Black
raspberry
|
4/3/2009
|
3
|
Far
E end by fire break; narrow patch along break; also some East of the fire
break
|
|
50
|
43.10448431
|
-89.80189255
|
Unit
21
|
Black
raspberry
|
4/18/2009
|
5
|
Near
top, W of Ridge Prairie; large; good area to plant
|
|
51
|
43.10472043
|
-89.80143623
|
Unit
21
|
Blackberry
|
4/18/2009
|
2
|
Moderate
|
|
52
|
43.10612004
|
-89.80752091
|
Unit
6
|
Black
raspberry
|
3/19/2009
|
2
|
Top
of gully near S fire break; moderate
|
|
53
|
43.10624929
|
-89.80765586
|
Unit
6
|
Black
raspberry
|
3/19/2009
|
5
|
Up
from gully near bur oak grove; large loose clone
|
|
54
|
43.10630059
|
-89.80788318
|
Unit
6
|
Black
raspberry
|
3/19/2009
|
2
|
Nearer
gully than BR53, mixed in with sumac
|
By the beginning of 2010 we
had fairly good control of brambles except for red raspberry, which forms really
dense patches of brambles with stems growing very close together. The cut-and
-treat method is not recommended because the cut stems are so close together
and it is difficult to keep track of which ones had been treated. Fortunately,
most of the areas where we were cutting and treating did not have red
raspberries.
After almost ten years
working on bramble control, I found that the best way to control red raspberry is to spray (with 3.5% aqueous Garlon 3A) all
the resprouts that arise after burns. However, not all shoots come up at the
same time, so it is necessary to spray again two weeks after the first time,
and again after another two weeks. Monitoring again in mid-summer for any “escapes”,
and again the next year is also advisable.
The importance of annual burns
One of the most important reasons
why annual burns should be done in oak savannas is because of brambles. Putting
savannas on a three-year burn cycle, such as is often done for prairies, is
exceedingly ill advised. Savannas almost always have a “legacy” of woody
invasives, of which brambles are one of the most important. Giving woody
vegetation the chance to grow unimpeded for three years does serious damage to
the herbaceous understory. In addition, the savanna will not carry a fire well
with all those woody shrubs hogging the savanna floor.
We have been burning our
savannas annually for 15 years (since 2002).
The best time to search for
undesirable woody plants is after a burn. This photo, of the Unit 10 savanna,
was taken on March 28, 2017 (the spring burn had been done on Feb 22, 2017).
Note the absence of woody vegetation (except for the blow-downs). You could
walk from one end of this savanna to the other without encountering a single
obstacle. Compare with the 2008 photo shown above.
 |
| Bur oak savanna after 15 annual burns Note the absence of woody invasives |
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