managing ox-eye daisy at milagra ridge

2014 SUMMARY REPORT Treatment and management of ox-eye daisy (Leucanthemum vulagre) Milagra Ridge

September 11, 2014

Prepared by: Ruby Kwan Park Stewardship Program Golden Gate National Parks Conservancy Fort Mason, Building 201 San Francisco, CA 94123

J:\Community Programs\Bldg 34 Files\Park Stewardship\Restoration\SITES\Milagra Ridge\mr_experiments\leuvul_control\mr_levu_report_final_20140904.docx Milagra Ridge LEVU test plots 2

SUMMARY

In 2008, the Park Stewardship Program established plots to test different methods of treating and

managing non-native ox-eye daisy (Leucanthemum vulgare), which at the time was very abundant in the

Nike Basin subsite at Milagra Ridge despite years of manual removal with volunteers. Both herbicide

(2% Roundup Pro and 1.5 % Aquamaster) and manual removal with handpicks were tested. In addition

to the treatments, straw mulch was applied to selected plots to determine if the added component

would affect results.

As of 2014 the most important pieces of information taken away from this experiment are:

Regardless of the treatment, all methods worked in reducing ox-eye daisy to a few or no

individuals given a sufficient amount of time.

A layer of straw mulch helped speed up the process of reducing ox-eye daisy.

After six years of monitoring and re-treating ox-eye daisy, a few ox eye daisy plants germinated

in most plots, likely from the seed bank. Therefore, any ox-eye daisy control should entail long-

term follow-up. Continued monitoring is needed to determine the length of time required to

eliminate the population and exhaust the seed bank.


1. BACKGROUND

Ox-eye daisy (Leucanthemum vulgare) is a perennial non-native flowering plant in the Asteraceae family

(Figure 1). The flower blooms in April through August and is a prolific seed producer thus it is important

to remove this non-native before the seed heads develop and dispose of the biomass off-site.

Work performed records showed that ox-eye daisy was removed by volunteers since 2004 (see

Appendix 1). There is a possibility that ox-eye daisy was removed even earlier since the work from 2004

onward was categorized as follow up. However, supporting records were not found via the work

performed database or in GIS. Prior to 2008, hand removal by volunteers was the primary treatment

method and efforts were focused heavily in the Nike Basin. Nevertheless, ox-eye daisy over time

remained abundant in the Nike Basin leading to concerns about the efficacy of hand removal.

Furthermore, the lack of a cumulative historical map of ox-eye daisy distribution made it even more

difficult to assess the efficacy of hand removal once it started in 2004. As a result, the need to explore

different and best methods of controlling ox-eye daisy and creating a record of the species distribution

became pertinent.

Thus in 2008, the Park Stewardship Program (PSP) initiated a study that tested the effectiveness of

different treatment methods at controlling ox-eye daisy. In conjunction with this study, PSP created a

map of the known distribution of ox-eye daisy at Milagra Ridge based on field observations, historic GIS

shapefiles, and work performed records. The goal was to help inform on-going and best management

practices for this species.

2. METHODS

2.1 Establishing test plots

Five 2 meter X 2 meter plots were created at the Nike Basin subsite of Milagra Ridge. The location of the

plots were selected 1) for a high density of ox-eye daisy, 2) to represent a range of ox-eye daisy life

stages as determined by plants with basal (younger) vs. cauline (older) leaves as well as plants with

flowers (younger) vs. seed (older), and 3) to represent a range of habitat types (grassland, shrubland,

mix). Each plot was mapped using a GPS unit and plots were marked on the ground with four wooden

stakes labeled with the plot number (Figure 2).

We assigned a different treatment method for each plot, each a variation in hand removal and foliar

treatment techniques. Plots 1, 2, and 3 were hand removal plots using only hand picks. Plots 4 and 5

were 2% Roundup Pro treatment plots and both switched to a 1.5% Aquamaster treatment in 2011. In

2010, mulch was added to Plots 3 and 5 in addition to the regular treatment as specified.


2.2 Annual treatment and monitoring

The plots were monitored and treated each year. Table 1 shows the treatment method and timing from

2008 through 2014. Before removing any ox-eye daisy, we recorded the plot number and date, and

took a before picture of the plot. Then, the ox-eye daisies at all life stages were removed/treated using

the method as specified unless otherwise noted. An after photo was taken post-removal, and we

recorded the time it took to remove the ox-eye daisy, the general life stage of the individuals removed,

how many were removed, treatment, who worked in the plot and how many people. The procedures

were repeated for the remaining plots. The ox-eye daisies removed were placed in a trash bag and

disposed of to prevent seed dispersal. Table 2 shows a sample dataset that was recorded as part of

treatment and monitoring in 2012.

FIGURE 2. Location of test plots at Milagra Ridge.


TABLE 1. Treatment methods per plot.

2008 2009 2010 2011 2012 2013 2014

Plot 1 Hand removal Hand removal Hand removal Hand removal Hand picks Handpicks Handpicks

Plot 2 Hand removal Hand removal Hand removal Hand removal Hand picks Handpicks Handpicks

Plot 3 Hand removal Hand removal Hand removal

and straw mulch Hand removal Hand picks Handpicks Handpicks

Plot 4 2% Roundup Pro 2% Roundup Pro 2% Roundup Pro *1.5% Aquamaster 1.5% Aquamaster Handpicks Handpicks

Plot 5 2% Roundup Pro 2% Roundup Pro 2% Roundup Pro and straw mulch *1.5% Aquamaster 1.5% Aquamaster Handpicks Handpicks

Treatment timing May/ June July/ August

* Partially treated in November

TABLE 2. The information contained in this table was recorded for each plot during monitoring and treatment each year.

Plot Date Time (min)

# Mature Plants and Seedlings

Condition # Workers Plot Set Up Treatment

1 8/30/2012 10 30 Small, 1 flowering, most leaves turning purple

3 Marcela Maldonado, Zachariah Jeffeson, Eira Whitty

Hand picks

2 8/30/2012 7

7 4 post flowering, green and yellow leaves

3 Marcela Maldonado, Zachariah Jeffeson, Eira Whitty

Hand picks

3 8/30/2012 3

5 2 flowered, green leaves 3 Marcela Maldonado, Zachariah Jeffeson, Eira Whitty

Hand picks

4 8/18/2012 3

4 Basal and flowers 2 Cody Ender, Marcela Maldonado

1.5% Aquamaster

5 8/18/2012 1

0 N/A 2 Cody Ender, Marcela Maldonado

1.5% Aquamaster

2.3 Mapping

A map of historical ox-eye daisy patches was created using information from work performed databases,

invasive vegetation maps, and field observations since 2008.

3. RESULTS AND DISCUSSION

3.1 Ox-eye daisy removal

Monitoring was not done in 2009 and data was not collected in 2010 at Plots 4 and 5. Since 2013, ox-eye

daisy was hand removed at all the plots because the abundance of individuals at each plot was few to

none which is a good sign that all of the treatment methods were effective in removing ox-eye daisy

over a span of six years (Figure 3).


Mulch was applied in Plots 3 and 5 in 2010. One year later (2011), the number of ox-eye daisy were

greatly reduced in these plots as compared to non-mulched plots. However, two years later (2012), ox-

eye daisy was at similar low levels in all plots. While the mulch speeded up the process, all treatments

seem to have similar levels of success in the long run, in this case, after six years. With diligent follow

up, ox-eye daisy is greatly reduced, but not eradicated from any of these plots after six years of

treatment. This underscores the importance of long-term follow up.

We were initially concerned that the mulch would break down and provide added biomass and moisture

to support ox-eye daisy regrowth. However, after monitoring in 2014, we saw that ox-eye daisy

appeared in equal amounts (at least 1 plant) in plots with and without mulch.

The largest patch of ox-eye daisy is located at the Nike Basin. However, patches and individuals were

observed in other locations at Milagra Ridge, in particular patches of basal rosettes in the Northwest

Prairie. The current map of ox-eye daisy at Milagra Ridge is important for informing management

practices and serve as historical documentation for which others can use as a reference farther down

the line (Figure 4).

FIGURE 3. Annual comparison of ox-eye daisy abundance at each plot. Plots were not monitored in 2009. Plots 4 and 5 were

not monitored in 2010.

120

20

60 72

20

127

27

57

82

12

39

4

30

7 5 4

19

1 4 4 6 2 2 4

0

20

40

60

80

100

120

140

Hand Removal Hand Removal Hand Removal 2% Roundup Pro;1.5% Aquamaster in

2011

2% Roundup Pro;1.5% Aquamaster in

2011

Plot 1 Plot 2 Plot 3 - Mulch in2010

Plot 4 Plot 5 - Mulch in2010

# o

f in

div

idu

als

rem

ove

d

2008 2010 2011 2012 2013 2014


3.1 Labor

We assessed the time spent on each technique. Hand removal with volunteers is the most time

consuming, followed by hand removal with staff/interns then herbicide. Herbiciding ox-eye daisy covers

more area in a shorter amount of time; however, the time needed for herbicide prep and clean up

reduces the time actually spent removing and treating ox-eye daisy. Therefore, hand removal is the

most straightforward method to remove ox-eye daisy while offering similar levels of success over the

long-term especially since ox-eye daisy numbers are minimal at Milagra Ridge.

FIGURE 4. Location of known historical patches and individual ox-eye daisy.


TABLE 3. Summary of work hours contributed to remove ox-eye daisy from test plots. Area is based on the total area treated or

hand removed between 2008 and 2014.

4. RECOMMENDATIONS

Continue checking plots until no ox-eye daisy is observed and removed for 2 years to determine the

length of time required to eliminate population and exhaust the seed bank.

Continue to check for and remove ox-eye daisy between April through in the Nike Basin and

Northwest Prairie. It is imperative to check known locations of ox-eye daisy weekly in order to limit

seed set.

If a new patch of ox-eye daisy is located, straw mulch should be applied after removal of basal

rosettes and flowers.

Control efforts should be implemented for over the long term (more than six years) and all sources of

seed diligently removed each year.

5. DATA STORAGE

Information pertaining to the ox-eye daisy test plots can be found at:

This report: J:\Community Programs\Bldg 34 Files\Park Stewardship\Restoration\SITES\Milagra Ridge\mr_experiments\leuvul_control\mr_leuvul_writeup_20140630

Photodocumentation: J:\Community Programs\Bldg 34 Files\Park Stewardship\Restoration\SITES\Milagra Ridge\mr_experiments\leuvul_control\Photodocumentation

GIS: O:\gis_projects\_SSP\Milagra_Ridge\veg_invasives\leu_vul

Treatment

Total # of

minutes

Total # of

individuals minutes/individual Total area area /min./individual

Herbicide -

staff/interns 24 18 1.33 40 30

Hand removal-

staff/interns 55 30 1.83 64 35

Hand removal -

volunteers 315 90 3.50 36 10

Appendix 1. Work performed records for ox-eye daisy removal

managing ox-eye daisy at milagra ridge

Documents

ox eye daisy plants

oxeye daisy control

eye daisy distribution

retreating oxeye daisy

management of ox

different methods

efficacy of hand removal

selected plots