APPENDIX A
CITY INTEGRATED PEST MANAGEMENT POLICY
P
LANT DISEASE MANAGEMENT
W
ith few exceptions, plant diseases do not constitute a severe enough problem to require extensive control efforts. Leaf blights caused by anthracnose, powdery mildew and entomosporium leaf spot can occur on several of our city’s tree and shrub species and can at times cause severe and repeated defoliation. These problems are weather dependent. That is, they spread during specific weather conditions. When weather conditions change, the disease subsides, and the problem resolves itself.
While control can be achieved chemically, it would typically require many repeat applications during these specific weather conditions. Because of these factors a non- chemical approach is utilized with these diseases; no action thresholds set for parks with the exception being Luther Burbank Home & Gardens. (See Luther Burbank Home & Garden Pest Management Action Thresholds table below.)
ANI
MAL PEST MANAGEMENT
I
nsects
Insect pest management involves controlling damaging insects and those causing nuisance problems. These pests can cause significant flower and foliar damage, physically weaken plants, spread disease, and provide opportunities for disease and other insects to invade plants. Although control can be achieved through a variety of methods, focus on plant health resolves most cases.
T
he typical insect pest problems found in the city involve only a few insect pests and a handful of plant species. Whether this is fully attributable to beneficial insect diversity or because the plants that remain are those that suffer fewer insect pest problems and/or can tolerate higher insect populations is not known.
M
echanically, pests and/or infested plant parts should be removed by hand when possible.
Removal of “brood wood” is effective in controlling certain insect species. Periodic, high pressure water washes can be used when insect populations are low.
C
ulturally, maintenance of plant health is of foremost importance in insect pest control. Properly cared for plants are less stressed and therefore less susceptible to insect (and disease) attack. Along the same lines, plant materials should be selected with care, matching species to conditions present at the site.
B
iologically, beneficial insects provide the single greatest effort in controlling plant pests. This has resulted i n few insect pest outbreaks, many of which require no attention on our part.
Maintenance of beneficial insects is the key to controlling pest problems. This is accomplished by encouraging additional beneficial insects’ habitat.
C
hemicals may be a directive of the City Council, County or State for public health or neighboring Attachment 2
economic crop loss reasons. Those pesticides that are reduced risk are to be considered first. The use of attractants in conjunction with traps can be used, though this approach is mos t effective in dealing with specific pests and best used when monitoring pest levels. No action thresholds are necessary, currently, for park lands except for Luther Burbank Home & Gardens. (See Luther Burbank Home & Garden Pest Management Action Thresholds table).
Bees
Bees are a beneficial insect of immeasurable value because of their pollination efforts. Bees in general are not viewed by the city as threatening though bee stings are painful and cause extreme allergic reactions in some people. Management activities are designed to eliminate plant materials that are attractive to bees.
Where possible, every effort should be made to preserve bee populations in physical activities and in the selection and use of pesticides. Occasionally situations arise when the removal of a hive by a beekeeper is necessary.
Wasps, hornets, yellowjackets
These groups of stinging insects are collectively known as wasps. Most of these species are beneficial in they are predatory on soft -bodied insects and are best known for their aggressive, unwanted behavior. Their stings are painful and can cause extreme allergic reactions.
Yellowjackets may reach nuisance level in park s during the late summer and fall. The Marin/Sonoma Mosquito & Vector Control District is currentl y offering nest eradication for clearly identified yellowjacket ground nest.
Digger bees (digger wasps, sand wasps)
This is an interesting insect closely related to the wasp group. They are found in large colonies in most of the sand play areas in our pa rks. This beneficial insect looks and behaves like a yellow jacket and can be a cause for alarm. Though fully capable of stinging, this insect is not aggressive and is no cause for concern. Manage by regularly racking playground sand areas to disturb and discourage nesting activities.
Spiders
This county has many spider species found in a variety of habitats. The black widow spider is also beneficial though its bite is painful and can be fatal. Control of black widow spiders is rarely warranted and more often when single female is found, it is eliminated via mechanical means.
Gophers & Moles
While gopher and mole are quite different in appearance, diet, and behavior, both are burrowing rodents that damage the landscape. Gophers create the greatest landscape damage by digging subterranean tunnels. Gophers also gnaw and damage plastic water lines and lawn systems. Their tunnels can divert irrigation water and destroy layers of soil in athletic fields, such as the soccer fields at A Place to Play Park. Gopher mounds in park turf grass areas interfere with mowing equipment and are oftentimes enlarged by dogs creating larger holes. Collapsed tunnels are another tripping hazard in turf grass. Gophers can also undermine structural integrity of dam and levee surfaces by increasing infiltration into the dam face which increases chance of dam failures. Most of the city’s dams fall under regulations by the California Department of Water Resources’
Division of Safety of Dams. It is imperative to reduce costly gopher damage by eradication prior to establishment within turf fields and dam surfaces. Refer to UC IPM Pocket Gopher for more information about life cycles and management tips.
Ground Squirrels
Ground squirrels injure many types of plants, harbor diseases harmful to humans, and their burrowing damages landscapes. Ground squirrels are common in this area and large colonies exist at Howarth Park. Their nest hole burrow can get quite large, having the potential to be a trip hazard and cause soil erosion issues. Abundant population can lead to unnatural, aggressive food stealing interaction with humans. Ground squirrels present a potential for catastrophic hazards if allowed to burrow in the Lake Ralphine dam at Howarth Park or the two dams at Fountaingrove Lake within Nagasawa Park. The State Division of Safety of Dams requires eradication of burrowing animals. Refer to UC IPM Ground Squirrels for more information about life cycles and management tips, http://ipm.ucanr.edu/QT/groundsquirrelcard.html .
LUTHER BURBANK HOME & GARDENS
The Luther Burbank Home & Gardens (Gardens) is a two-acre site in downtown Santa Rosa that was Burbank’s residence and where he conducted a large part of his plant research. This site is a Registered National Historic Landmark and is visited by thousands of people from around the world annually.
The gardens offer a glimpse at the wide variety of plant materials with which Burbank worked.
These are displayed in demonstration gardens throughout the site and include species he worked with and varieties representative of those he developed. Other garden displays include a drought tolerant garden, sensory garden with plants selected for touch and smell qualities, a garden designed to attract birds and a border garden that illustrates the plant materials used for landscaping in Burbank’s day.
Because of the amount and variety of landscape materials fo und in the Gardens, insect pests and plant disease levels can reach elevated levels quite rapidly. Insect pests rarely reach levels needing chemical treatment because this wide plant diversity supports many beneficial insects. Plant diseases, however, can and do reach damaging levels quite rapidly. Fortunately, most of these diseases are host specific and do not spread between different plant species.
Many of the maintenance activities inside the Gardens are thankfully performed by a large contingent of knowledgeable volunteers whose various tasks include hand removal of pests and plant parts that infested or infected with insects or disease. Additionally, these volunteers can provide the visitor with valuable horticultural information including IPM.
ACTION THRESHOLDS CHARTS
VEGETATION MANAGEMENT
ACTION THRESHOLDS
GENERAL LANDSCAPED AND OFFICE BUILDING AREAS
LOCATION
ACTION THRESHOLD
ACTION
All areas of city responsibility.
Weeds covering 10% or less of
the ground where not desired.
Mechanically remove.
Use weed burner.
Where possible, add mulch to a
minimum depth of 4 inches.
Consider the use of densely
growing plant materials.
Weeds cover more than 10% of
the ground where not desired.
Any of the above non-chemical
tactics.
Spot treat with appropriate
herbicide.
Weeds cover 5% or less of the
ground in planter beds.
Mechanically remove.
Use weed burner.
Where possible, add mulch to a
minimum depth of 4 inches.
Consider the use of densely
growing plant materials.
Weeds cover more than 5% of
the ground in planter beds.
Any of the above non-chemical
tactics.
Spot treat with appropriate
herbicide.
Any area historically requiring
weed control measures.
Spring and/or Fall application of
pre-emergent herbicide.
VEGETATION MANAGEMENT
ACTION THRESHOLDS
TURF AREAS
LOCATION
ACTION THRESHOLD
ACTION
All turf areas.
Broadleaf or grassy weeds cover
less than 20% of the turf area.
Observe proper mower
sanitation.
Remove mechanically.
Re-evaluate cultural practices,
test soil fertility.
Broadleaf or grassy weeds cover
20% or more of the turf area.
Any of the above tactics.
Spot treat with appropriate
herbicide.
Turf edges that can be edged
with power edger.
Any time edging is necessary.
Use power edger.
Turf edges that cannot be edged
with power edger.
Turf growing up to 3 inches
over pavement edge.
Remove mechanically.
Use weed burner.
Turf growing more than 3
inches over pavement edge.
Any of the above tactics.
Spot treat with appropriate
herbicide.
Turf irrigation heads
Turf growing around head
causing water to pond or other
disruption of proper operation.
Mechanically remove.
Vertical mow to remove built-
up thatch.
Raise head in extreme case.
VEGETATION MANAGEMENT
ACTION THRESHOLDS
ATHLETIC FIELDS
LOCATION
ACTION THRESHOLD
ACTION
All areas of city responsibility.
Winter weed removal for pre-
season preparation of baseball
and softball fields.
Mechanically remove weed
growth with field drags.
Spot treat with appropriate
herbicide.
Turf encroached up to 12 inches
into bare areas of ball diamonds.
Mechanically remove.
Use weed burner.
Turf encroached 12 inches or
more into bare areas of ball
diamonds.
Any of the above tactics.
Spot treat with appropriate
herbicide.
30% of field lines have
unwanted regrowth.
Mechanically remove.
Spot treat with appropriate
herbicide.
MISCELLANEOUS AREAS
LOCATION
ACTION THRESHOLD
ACTION
Asphalt or concrete roads,
pathways, parking areas or other
paving and hard surfaces.
Weeds growing in joints or
cracks.
Mechanically remove.
Use weed burner.
Any of the above tactics.
Spot treat with appropriate
herbicide.
Surplus properties, roadsides,
pathways, other R-O-W sites
such as fire hydrants traffic
signal control boxes.
Weeds & other unwanted
vegetation cover less than
25% of the area.
Mechanically remove.
If possible, add mulch to a
minimum depth of 4 inches.
Weeds & other unwanted
vegetation cover 25% or more
of the area.
Any of the above tactics.
Treat with appropriate herbicide
.
ACTION THRESHOLDS
TRAFFIC MEDIANS
LOCATION
ACTION THRESHOLD
ACTION
All traffic medians.
Weeds cover 5% or less of the
surface of landscaped median.
Mechanically remove.
Use weed burner.
Add mulch to a minimum depth
of 4 inches.
Consider the use of densely
growing plant materials.
Weeds cover more than 5% of
the surface of landscaped
median.
Any of the above tactics.
Treat with appropriate herbicide.
Weeds cover 10% or less of the
surface of non-landscaped
median.
Mechanically remove.
Use weed burner.
Add mulch to a minimum depth
of 4 inches.
Consider the use of densely
growing plant materials.
Weeds cover more than 10% of
the surface of non-landscaped
median.
Any of the above tactics.
Treat with appropriate herbicide
Weeds in the concrete
cracks/joints of any median
cover less than 5% of the area
or are less than 6 inches in
height.
Mechanically remove.
Use weed burner.
Weeds in the concrete
cracks/joints of any median
cover 5% or more of the area or
are 6 inches or more in height.
Any of the above tactics.
Treat with appropriate herbicide.
VEGETATION MANAGEMENT
ACTION THRESHOLDS
POISON OAK - BLACKBERRIES - UNWANTED TREES/SHRUBS
LOCATION
ACTION THRESHOLD
ACTION
All areas of city responsibility.
Poison oak growing in any area
with potential for contact.
Blackberry thicket to be
partially or fully removed.
Blackberries growing in
landscaped areas.
Remove mechanically.
Treat regrowth with appropriate
herbicide.
Treat regrowth with appropriate
herbicide.
NOTE: When chemical treatment of blackberries is warranted, non-fruiting canes may be treated at any time. Any stands containing fruiting canes can only be treated after all fruit has dried.
Unwanted weed species; tree or
shrub.
Remove mechanically.
Remove stump.
Treat stump and regrowth with
appropriate herbicide.
AQUATIC WEEDS
LOCATION
ACTION THRESHOLD
ACTION
Boat launches, dams, spillways
and around fish pier at Howarth
Park/Lake Ralphine, Nagasawa
Park/Fountaingrove Lake and
Francis Nielsen Ranch Park/
Nielsen Pond, Meadowlane
Ponds, Delta Pond, Brown Farm
Pond, Alpha Farm Ponds, and
Ambrosini Pond.
Eurasian water milfoil growing
to within 18 inches of water
surface.
Treat with appropriate herbicide
per Fish & Wildlife and/or
Water Board permit.
Explore viable biological and
mechanical control methods.
Less than 1% coverage Cattails,
bulrush, and other tulles weeds
growing on the dams, near
spillways, boat ramps, areas
creating mosquito habitat and
areas where summer flows are
restricted which may cause
siltation increases chance of
winter flooding.
Evaluate site for modifications,
such as dredging.
Mechanically remove when
water levels are at their lowest
in the late summer.
Treat regrowth with appropriate
herbicide in spring.
Floating weeds such as
mosquito fern (Azolla spp.),
duckweeds (Lemna spp. &
Spirodela spp.) and Watermeal,
(Wolffia spp.) covering 5% of
the water surface.
Mechanically remove by netting
and hauling-off.
Treat with appropriate herbicide
allowable by permit.
Blue algae and other algae
species.
Aerate or increase water
circulation.
Biological treatment of
beneficial bacteria.
Physical application of aquatic
black pond dye to reduce
sunlight penetration.
GOPHER & MOLE PEST MANAGEMENT
ACTION THRESHOLDS
LOCATION
ACTION THRESHOLD
ACTION
All areas of city responsibility.
Evidence of mole is observed.
Physically remove mole.
Trap; to be set only where it
can be done safely.
1 gopher mound in any turf
area, annual planting bed, or
dam structure OR 10 mounds
in any 1,000 square feet of
planted areas OR 20 mounds
in any 1,000 square feet of
non-planted areas.
Trap in turf non-layer
athletic fields.
Bait or fumigate in athletic
fields and dam structures.
Provide control of broadleaf
weeds if in turf.
GROUND SQUIRREL PEST MANAGEMENT
ACTION THRESHOLDS
LOCATION
ACTION THRESHOLD
ACTION
All areas of city responsibility.
Any ground squirrel burrows
entrance that is a hazard.
Fill in burrow entrance.
Bait; stations to be safely set
within burrow.
Any ground squirrel
burrowing within 50 feet of
the base of dam at Lake
Ralphine.
Bait; stations to be safely set
within burrow.
LBH&G PEST MANAGEMENT
ACTION THRESHOLDS
LOCATION
ACTION THRESHOLD
ACTION
ROSES
RUST: susceptible varieties
showing 15% of foliage infected
with rust,
OR
Weather conditions favor
development of disease; 55-
75°F and wet foliage.
Provide proper soil moisture
and fertility.
Remove infected plant parts
including those which have
fallen.
Remove infected canes when
dormant pruning.
Avoid overhead watering.
Treat with fungicide.
Apply fungicide with dormant
spray.
Replace with resistant varieties.
BLACKSPOT: Susceptible
varieties showing signs of
infection on 10% of foliage,
OR
Weather conditions favor
development of disease; 55-
75°F and wet foliage.
Provide proper soil moisture
and fertility.
Remove infected plant parts
including those which have
fallen.
Remove infected canes when
dormant pruning.
Avoid overhead watering.
Treat with fungicide.
Apply fungicide with dormant
spray.
Replace with resistant varieties.
LOCATION
ACTION THRESHOLD
ACTION
ROSES, ZINNIA, DAHLIA,
CALENDULA, OTHER
SUSCEPTIBLE BEDDING
PLANTS.
POWDERY MILDEW:
Susceptible varieties showing
signs of infection on 10% of
foliage.
Provide proper soil moisture
and fertility.
Remove infected plant parts +
those which have fallen.
Remove infected canes when
dormant pruning.
Prune to promote air circulation.
Apply water in mid-afternoon
(on roses: only to varieties
resistant to Blackspot and Rust).
Treat with fungicide + with
dormant spray.
Replace with resistant varieties.
ROSES
APHID: 15 aphids found on
terminal 6 inches including
flower bud.
Insure proper cultural needs,
avoid high nitrogen levels.
Water wash at any time.
Remove infested parts.
Control ants if possible.
Treat with insecticide, + with oil
in dormant spray.
STONE FRUITS
APHID: 10 aphids found on any
10-leaf sample,
OR
Distortion affects 15% of
foliage.
GLADIOLUS
THRIPS: 2% of foliage showing
damage.
Insure cultural needs.
Remove severely infested
plants. Introduce beneficial
insects.
Treat with insecticide.
Rotate beds in future years.
Remove corms to dry.
LOCATION
ACTION THRESHOLD
ACTION
All landscape plants.
MITES: damage visible on 25%
of foliage.
Address cultural needs.
Address problems that promote
population build-ups.
Inspect for beneficial species.
Treat with miticide.
WHITEFLY: individuals of any
growth stage present on 10% of
foliage.
Address cultural needs.
Inspect for beneficial species.
Release parasitic wasps.
Remove infested plant parts.
Treat with insecticide.
SCALE: visible on 15% of
branches.
Address cultural needs.
Inspect for beneficial species.
Remove infested plant parts.
Treat with insecticide.
Use oil in with dormant spray.