Pitch canker and California pines: what line-clearance crews watch for

Sep 21

22 min read

Pitch canker, caused by Fusarium circinatum, infects most California pines and Douglas-fir. The State Board of Forestry declared the Coastal Pitch Canker Zone of Infestation on June 4, 1997, covering all or parts of 21 counties. The zone reaches the movement, disposal and use of infected wood rather than the clearance.

A crew working a coastal California distribution circuit is almost certainly standing inside a zone of infestation that was declared before most of the poles in the span were last inspected. The State Board of Forestry approved the Coastal Pitch Canker Zone of Infestation at a regular meeting in Visalia on June 4, 1997. It covers all or parts of 21 counties, from Mendocino County to the Mexican border. It was the first zone the Board had ever declared for a tree disease.

The zone authorizes one thing, which is control of the movement, disposal and use of infected wood. Clearance distances and inspection cycles come from other instruments entirely. That single fact decides where pitch canker shows up in a line-clearance program, and it shows up in three places:

The branch tips flagging over the conductor.
The removal decision on a pine the property owner wants kept.
The back of the chip truck at the end of the day.

The disease is live. The 2024 California Forest Pest Conditions report records that Torrey pines at Torrey Pines State Natural Reserve were free of pitch canker until 2023, and that the pathogen has since spread widely in the Reserve and beyond.

The zone was declared in 1997, and it reaches the wood

The instrument is a resolution, and it recites its own authority in the first line:

WHEREAS, Public Resources Code, Article 5, Section 4712 through Section 4718 provides that whenever the Director determines that there exists an area which is infested or infected with plant diseases injurious to timber or forest growth and that the infestation or infection is of such a character as to be a menace to the timber or timberlands of California, the Director, with the approval of the State Board of Forestry, may declare a zone of infestation and describe and fix its boundaries

What a Zone of Infestation does under the Public Resources Code is set out elsewhere in this set, on the oak borer that has one, and the statute itself is section 4716. What matters here is the operative clause the Board actually adopted, because it is narrower than the statute allows:

BE IT FURTHER RESOLVED that the Director, in accordance with the established Forest Pest Management policy of the State Board of Forestry, and in the absence of action by other agencies, is hereby authorized to take actions which would control the movement, disposal and use of woody material infected with Pitch Canker

Three words in that sentence do most of the work. Movement, disposal and use. The clause reaches material. Standing trees, clearance distances, inspection intervals and the prescription a crew works to at the pole all come from somewhere else. There is also a condition on the whole grant, which is that the Director acts in the absence of action by other agencies. The agency that acts first, in practice, is the county.

The full resolution is published by the Pitch Canker Task Force at Cal Poly's Urban Forest Ecosystems Institute, signed by Dean Cromwell as Executive Officer and Robert Kerstiens as Chairman. The boundary is described the way a 1997 boundary was described, which is by highway:

All of the area within the counties of Alameda, Contra Costa, Los Angeles, Marin, Monterey, Mendocino, Napa, Orange, San Benito, San Francisco, San Luis Obispo, San Mateo, Santa Barbara, Santa Clara, Santa Cruz, Solano, Sonoma, and Ventura; and the portion of San Bernardino, Riverside and San Diego Counties which is westerly of the line beginning at the San Bernardino / Los Angeles County line and proceeding easterly along State Route (SR) 138 to Interstate Highway (I) 15; thence southerly along I-15 to I-215; thence southerly along I-215 to I-15; thence southerly along I-15 to SR-79; then southerly along SR-79 to I-8; thence easterly along I-8 to the San Diego / Imperial County line; thence southerly along the San Diego / Imperial County line to the U.S. / Mexico border.

Eighteen whole counties and three partial ones. A Southern California program can locate itself on that line without a map: SR-138, I-15, I-215, SR-79, I-8. West of it is inside.

The Board still publishes a map of the zone on its Zones of Infestation page. The map carries one note, "Pitch Canker data acquired from FRAP," and leaves its date of issue blank. A file that cites the map as its source for a county should record the date it was downloaded.

The money behind the zone has a date too, and it ran out. Senate Bill 1712, introduced by Senator McPherson and Assembly Member Keeley, was signed by Governor Pete Wilson on September 21, 1998. It gave the Department of Forestry and Fire Protection $350,000 a year for six years, $2.1 million in total, for work that included preventing transportation of infected plant material from infested to uninfested areas. A program reading the Task Force guidance today is reading a document written while that funding existed.

Three county lists, and they disagree

An inventory field that records whether a tree is "in the zone" has to choose a source. Four are in circulation, and they name different counties.

Source	Counties named	Notable
Board of Forestry resolution, June 4, 1997	18 entire, plus parts of San Bernardino, Riverside and San Diego	The legal boundary. San Diego only west of the described line
Pitch Canker Task Force, counties with infestations	16	Drops Napa, Solano and Ventura. Adds San Diego outright
UC IPM Pest Notes 74107, May 2013	"18 coastal counties"	Names a count rather than a list
CDFA pest rating proposal, official state records, 2022	14	Includes Nevada County, which is outside the coastal zone

The last row is the one worth stopping on. CDFA's official detection records name Nevada County, in the Sierra foothills, well east of a zone drawn along the coast. The host list attached to those records includes Pinus sabiniana.

Gray pine is a foothill and valley species, and its corridor problem is a fork, but its presence on a pitch canker record list puts the pathogen on a host whose range runs well inland of the zone. CDFA's own text records the same movement inland, describing detections in Douglas-fir in a breeding orchard in El Dorado County, at 1,000 meters elevation, about 3,300 feet.

The Task Force resolves the ambiguity the way a field program has to resolve it:

Know if you are in an infested area. If you are unsure, assume you are within an infested area whenever working with pine within an infested county.

Who decides for real is the County Agricultural Commissioner. CDFA's pest rating proposal is explicit that the rating has carried a regulatory consequence for more than two decades:

Pitch canker has been an unofficial "B"-rated disease since 2001. As a result, the local or destination California County Agricultural Commissioner may restrict the movement of known infected host material, and nursery cleanliness standards apply.

CDFA's 2022 proposal kept the rating at B, with a comment period running March 21, 2022 through May 5, 2022, and Heather J. Scheck named as responsible party. What a B rating authorizes, and the mechanism it runs through, is set out in this set on the Mediterranean oak borer, which carries the same rating. The short version for a pine crew is that the reach of a B rating is a shipment, and the discretion sits with a county office rather than with the state.

Which pines on the circuit are hosts

The species question has a published answer, and it is more useful than the county question because it can be settled by looking at the tree. UC IPM's Pest Notes prints a susceptibility table for conifers grown in California, rated two ways: by greenhouse inoculation and by observation of natural infections in the field.

Species	Common name	Status	Greenhouse	Field
Pinus attenuata	knobcone pine	native	S	S
Pinus canariensis	Canary Island pine	exotic	R	R
Pinus contorta ssp. contorta	shore pine	native	S	S
Pinus contorta ssp. murrayana	lodgepole pine	native	S	N
Pinus coulteri	Coulter pine	native	S	S-
Pinus eldarica	Eldarica pine	exotic	S	N
Pinus halepensis	Aleppo pine	exotic	S	S
Pinus jeffreyi	Jeffrey pine	native	S	N
Pinus lambertiana	sugar pine	native	S	N
Pinus monophylla	pinyon pine	native	S-	N
Pinus muricata	bishop pine	native	S	S
Pinus pinea	Italian stone pine	exotic	R	R
Pinus ponderosa	ponderosa pine	native	S	S-
Pinus radiata	Monterey pine	native	S	S
Pinus sabiniana	gray pine	native	S	S-
Pinus sylvestris	Scotch pine	exotic	S	N
Pinus thunbergii	Japanese black pine	exotic	R	N
Pinus torreyana	Torrey pine	native	S	S-
Pseudotsuga menziesii	Douglas-fir	native	S-	S-

S is susceptible. R is resistant. S- means most tested individuals were resistant but a small percentage appeared moderately susceptible, or in the field column that infected trees have been seen but too few to estimate. N means untested, or observed too seldom near natural inoculum for the absence of disease to carry weight.

Four rows change what a pre-inspector writes down. Canary Island pine and Italian stone pine are rated R in both columns, and both are common street and right-of-way trees in California. Aleppo pine is rated S in both, and it is the pine planted by the thousand along Southern California roadsides.

Monterey pine is S in both, and CDFA records tens of millions of planted trees statewide, popular for plantings on freeway rights-of-way where they serve as visual and sound barriers. The tree in the span is usually a planted tree, a long way from anywhere the species is native.

Douglas-fir sits at the bottom of the table with two S- ratings and one behavior that matters more than either:

Infections of Douglas-fir often induce no symptoms: consequently, infected seedlings or cuttings may serve as vehicles for dissemination of the pathogen.

A Douglas-fir carries this silently. The failure modes that put a Douglas-fir on a circuit are height and fall zone, and pitch canker leaves that assessment where it stood. It adds a reason to treat the wood the same way as pine wood when the tree comes down inside the zone.

What the flagging looks like from the ground

The pathogen is Fusarium circinatum. It creates lesions that girdle branches, exposed roots and trunks. The needles beyond a girdled branch turn yellow, then brown, then drop, leaving a bare tip. UC IPM records one structural fact about the fungus that governs the whole inspection:

The fungus isn't known to move within the tree; therefore, each canker or lesion is a separate and distinct infection.

So a crown with twenty flagged tips has sustained twenty separate infections. Counting tips is counting events, which is why a tree can hold a stable number of flags for years. It is also why a tree with a stem canker sits in a different category from a tree with tip dieback. UC IPM records that flattened or slightly sunken cankers on the main stem usually appear only after the tree already has multiple branch infections.

Under the bark at a lesion the wood is honey-colored and resin-soaked. On a stem infection the resin can coat the bark several feet below the infection site, which is the symptom most likely to be visible from a road or a right-of-way while the crown still reads as green.

The 2024 California Forest Pest Conditions report describes what the field version looked like at Torrey Pines State Natural Reserve, where the disease arrived in 2023:

Infected Torrey pines are found widely in the Reserve and beyond and have dead branch tips with reflexed needles covered in pitch.

Reflexed needles covered in pitch is a description a crew can work from at 40 feet. The same report names the look-alike found on the same trees at the same time, and gives the discriminator:

Symptoms of Diplodia were brown or grey and remain attached to the stem. Small fruiting bodies at the base of the needles are also seen with Diplodia and are not seen with pitch canker infestations.

UC IPM prints a wider comparison table of pine maladies with overlapping symptoms. It includes Ips bark beetles, twig beetles, pitch moths, red turpentine beetle, western gall rust, dwarf mistletoe, and salt, wind or drought dieback. One row on that list is work the crew itself did: "injuries or pruning wounds," which UC IPM records as usually producing oozing or streaming pitch. A fresh cut bleeding resin on a Monterey pine is on the differential with the disease, and UC IPM is direct about how the question gets settled:

Though the disease can usually be diagnosed based on symptoms, diseased tissue must be cultured in a laboratory for a definitive identification.

A pre-inspection record that says "pitch canker" without a culture is recording a field opinion. A record that says "eleven flagged tips, resin on stem at 14 feet, honey-colored wood under bark" is recording what was seen, and it survives a second look.

Infection is not a reason to remove the tree

This is the point at which a line-clearance program is most likely to get pitch canker wrong, and the correction is published. The Pitch Canker Task Force position paper on retention of infected pines, revised September 25, 2001, states it plainly:

Pitch canker infection is not a sole reason to remove a tree. The decision to remove a tree should be based on more general criteria, such as safety. Thus, if a tree has been deemed hazardous for any reason, it should be removed, regardless of its prospects for recovery from pitch canker.

The reason to be conservative is that a large share of trees recover, and many were only lightly damaged to begin with. The Task Force's own figure is that approximately 10 percent of Monterey pines are at least somewhat resistant. The field record puts it higher. Gordon and colleagues, publishing in California Agriculture in 2020, reported on plots established in the native Monterey Peninsula forest in 1996 and monitored to 2013, and on a second set of younger-tree plots established in 2011:

Over the 3 years that plots were monitored, 50% of trees (151/304) sustained no infections, and 22% (66/304) had only one (fig. 2).

Inoculation trials on standing trees put resistance at 41.3 percent, 55 trees out of 133, in 2011, against 38.8 percent in 2002. Disease severity in the 1996 plots leveled off and changed very little over the following 14 years, and by the end of the observation period symptomatic trees had become a rarity across most of the forest. The authors attribute part of that to induced resistance and part to a reduction in coastal fog, which supplies the moisture infection requires.

That evidence cuts one way for the tree and the other way for the crew. Recovery happens in living tissue only, and the Task Force is equally clear about the rest of the tree:

Any recovery of the tree will be from living material. Infected trees may have numerous dead branches or the top section of the tree may be dead. Dead parts of the tree will not recover and will become increasingly weakened and unpredictable over time. Large dead material should be mitigated as soon as possible.

Dead branches over a conductor and a dead top are reachable by rule regardless of cause. Public Resources Code section 4293 names the condition directly:

Dead trees, old decadent or rotten trees, trees weakened by decay or disease and trees or portions thereof that are leaning toward the line which may contact the line from the side or may fall on the line shall be felled, cut, or trimmed so as to remove such hazard.

"Weakened by decay or disease" is the phrase pitch canker turns on, and the radial clearance rule that sentence sits inside carries it. The parallel dead-wood provision in GO 95 Rule 35 turns on the company's actual knowledge of dead, rotten or diseased portions overhanging a span. How far that trigger reaches on a live limb is worked through in this set on valley oak.

So the record a crew writes is about the wood. A pine with forty flagged tips and sound wood over the conductor is a monitoring item. A pine with a dead top above a primary is a prescription, and the species and the pathogen sit in the note as context rather than as the reason for it.

CDFA adds one detail that belongs in a hazard note rather than a disease note. Describing the resin bleeding that runs down trunk and lower branches, its assessment records that "at this point, the breakage of these branches and even the stem can often occur." A visible stem canker is a structural observation.

The cut is a wound, and this is a wound pathogen

The mechanism that makes pitch canker a line-clearance question rather than a forestry question is that infection normally needs a wound. Gordon and colleagues state it in one sentence:

F. circinatum is a wound-infecting pathogen, and, in California, wounds created by twig beetles (Pityophthorus spp.) can serve as infection courts

The insects that make those wounds are named. UC IPM lists engraver beetles (Ips species), twig beetles (Pityophthorus species), cone beetles (Conophthorus radiatae) and deathwatch beetles (Ernobius punctulatus) as capable of vectoring the pathogen. CDFA adds the feedback loop that makes an infected pine a magnet: branch dieback and excessive pitch at the lesions attract those same beetles, which attack the tree and cause more dieback.

A pruning cut is also a wound. The observation is old and it is in the arboricultural literature, in Arboriculture & Urban Forestry in October 1989, in a paper by McCain, Correll and Gordon testing whether wound dressings could prevent infection of fresh pruning wounds on Monterey pine:

Pruning wounds can become infected and one is quickly faced with a 'Catch-22' situation.

That paper found that products applied to fresh wounds before inoculation reduced infection, and that timing mattered, with thiabendazole applied after inoculation reducing infection by only 45 percent against no infections when it was applied first. It is a 1989 result, published under the pathogen's old name. UC IPM's 2013 Pest Notes and the Task Force's current management guidance both leave wound dressings out of the prescription. The finding that survives is the first sentence: the cut is an infection court.

Two things keep this from becoming an argument against pruning.

The first is that the Task Force and UC IPM both endorse pruning in the right circumstances. UC IPM's position is conditional and worth quoting because it is frequently reported without the second half:

Where trees have sustained a limited number of infections, removing symptomatic branches can effectively eliminate the disease. Of course, new infections can occur, and studies have shown that pruning doesn't slow the development of pitch canker in stands where the disease is well established.

So pruning out infections is a treatment on an isolated tree in a lightly infested area and a cosmetic measure in a heavily infested one. A clearance prune is a third thing. It is work the code requires for a different reason, and the disease leaves that requirement standing.

The second is that the wound is one pathway among several. CDFA records the qualification directly: "Wounding is not a requirement for shoot infection under all circumstances and F. circinatum can grow within pine shoot tissue without causing symptoms." Airborne inoculum is abundant, and infections can occur at any time of the year.

Where that leaves a program is honest to state. The scheduling and dressing of a clearance prune on a host pine sit outside every California instrument on this disease. The Public Resources Code is silent on it, GO 95 is silent on it, and the Task Force guidance addresses sanitation and disposal rather than the cut.

The decision belongs to the utility's own vegetation specification, and a contractor's job is to record which trees were cut, when, and with what equipment, so that the specification can be defended if anyone asks. The eucalyptus longhorned borer version of the same problem works through a different mechanism to a similar place.

San Francisco's window is November to February

One California agency has written the timing question down, for trees it owns and regulates. San Francisco Public Works, Bureau of Urban Forestry, publishes a pine pitch canker page, and its pruning answer is a season:

To reduce the spread of the disease, it is recommended to prune pine trees when the bark beetles are less active, from November to February. Unless you need to mitigate an immediate safety hazard, it is recommended to only prune pines during this period.

Four months, and a carve-out. The carve-out is the important half for a line-clearance crew, because it is a city agency resolving the collision in advance and in writing: an immediate safety hazard is mitigated when it is found. The window binds discretionary pruning.

A clearance cycle is mandatory work, scheduled around growth rate, voltage and inspection interval. Beetle flight sits outside that calculation. Most of the work on a coastal circuit will fall outside November through February simply because most of the year does. The seasonal restrictions a California utility program already works around are nesting bird windows and fire-season constraints. The pitch canker window remains a San Francisco recommendation.

The other line on the San Francisco page is a permit, and it applies to any contractor working a street tree in that city rather than only to a homeowner:

a permit is required to remove any street tree in San Francisco

That is a removal rather than a prune, and the decision about whether a tree is pruned or removed sits with the utility. The permit is the tree owner's obligation, and a crew that arrives to remove a dying Monterey pine on a San Francisco sidewalk without it in the package loses the day. San Francisco also records the clinical grounds for that removal: "trees with large dead limbs, a dead top, or trunk cankers are likely to die from the disease."

What happens to the logs and the chips

This is the part of pitch canker that the Zone of Infestation actually reaches, and it is the part a production program is most likely to breach without noticing. The Task Force publishes treatment thresholds, by material, and they are specific enough to write into a disposal procedure.

Material	What clears it for movement out of an infested county
Chips	Composting. Uncomposted chips should stay in the county
Compost	50 degrees Celsius, 120 degrees Fahrenheit, or higher for at least 10 days, with turning, so longer than 10 days in practice
Logs	Stockpiled one year or more inside the zone, or heated to 160 degrees Fahrenheit at the center for 75 minutes, or completely debarked with all bole cankers removed
Kiln-dried lumber	Center of the largest dimensional piece reaching 140 degrees Fahrenheit
Bark	Nothing listed. Pine bark should not be transported out of infested counties
Firewood	Local use only, seasoned under a tightly sealed clear plastic tarp

The guidance for the crew that generated the material is shorter and blunter:

Limbs and small pieces of wood from diseased trees may be chipped and the mulch deposited on site or they may be burned. Any material that is removed from the site should be tightly covered with a tarp during transit and taken to the nearest landfill or designated disposal facility for prompt burial, chipping and composting, or burning. Do not transport diseased wood out of infested counties.

Chip on site, leave the chips on site, and tarp anything that travels. That collides with a lot of production practice, and it collides in a particular way with a corridor, because what happens to the material left behind a crew is itself specified by the utility and sometimes by the landowner.

It also has a limit the Task Force states: "Avoid using potentially infested chips near healthy pines or Douglas-fir." Blowing chips into a right-of-way that still has healthy host pines in it is the one placement the guidance rules out.

Chipping reduces volume. Sanitation is a separate question, and the Task Force answers it twice, in statements worth reading together because they are about different organisms:

Chipping infected wood will reduce but not eliminate insects that carry the pitch canker pathogen. Chipping has little impact on pathogen survival and may serve to more thoroughly distribute the pathogen among the chips through contamination.

And in the older background section of the same guidance:

Chipping does not eliminate insects. When branch tips infested with twig beetles are chipped, some insects may emerge up to 12 weeks after chipping.

The Task Force's own pages are not consistent on this. One paragraph says chipping "does eliminate most insects," and the passage above says it does not eliminate them. Both survive on a page that has been revised in layers since 2000. The safe reading, and the one both versions support, is that chipping reduces insect survival and leaves the fungus intact. For a program that needs a defensible rule, the operative instruction is the same either way: keep the chips in the county, and keep them away from healthy hosts.

Survival times set the clock on everything above. The fungus survives in cut wood up to a year and in soil up to 8 weeks or more. Insects may survive in cut wood or chips for many months. A brush pile left for a later haul is inside those numbers.

Tools are the last item, and the guidance on them is written in capitals:

Tools and machinery which are used to cut trees with pitch canker disease WILL BECOME CONTAMINATED with the pitch canker fungus. There is little chance of spreading pitch canker if contaminated tools are only used on dead trees or on trees that are not pines. However, if contaminated tools or machinery will be used on living pines, the tools should be cleaned and sterilized before use on uninfected trees or in uninfested areas.

The sterilants named are Lysol or a 10 percent bleach solution, one part bleach in nine parts water, with a two minute soak. The realistic alternative is named in the same paragraph: reserve one set of equipment for infested areas and another for uninfested ones. A crew working entirely inside the zone and entirely on pines carries contamination all day, which is why the exception matters. The clean condition is set at the boundary of the zone rather than at the boundary of a tree.

One further obligation reaches only part of this work. CAL FIRE has authority to impose conditions on the commercial harvest of trees from timberland inside the zone, and for all timber operations the Department regulates, the Department must be informed if pitch canker is present in the operating area. Routine line clearance on a distribution circuit falls outside that definition. A right-of-way widening on timberland can fall inside it, and that is a question for the Registered Professional Forester on the plan rather than for the general foreman.

Second in the failure record, and nobody wrote the profile

The California Tree Failure Report Program collects failure reports by species. Monterey pine sits second on the list of species with 50 or more reports.

Species	Reports
Quercus agrifolia	797
Pinus radiata	592
Hesperocyparis macrocarpa	553
Eucalyptus globulus	385
Quercus lobata	363
Pinus pinea	191
Sequoia sempervirens	136
Pinus halepensis	132
Pseudotsuga menziesii	81
Pinus attenuata	62

The program attaches its own warning to those counts, and it is the right warning:

Report numbers for species do not provide an assessment of the frequency of failure for the species (i.e., how often a species fails relative to its occurrence in a population of trees).

A number that large reflects how many Monterey pines are planted in California as much as it reflects how they behave. What is missing is the synthesis. The Britton Fund publishes five structural failure profiles, for coast live oak, blue gum eucalyptus, Monterey cypress, valley oak and Italian stone pine. Italian stone pine has a profile at 191 reports. Monterey pine, at 592, is absent from that list.

So the species with the second largest body of California failure reports lacks a published breakdown of where it fails, in what weather, or with what defect visible beforehand. The gray pine page in this set makes the same observation from the other end, with a species that has too few reports to build one.

For Monterey pine the material exists and nobody has reduced it. Until somebody does, the failure record a program has for this species is its own, which is an argument for recording dimensions rather than adjectives on every pine that comes down in the corridor.

What a pitch canker record has to carry

The fields below are the ones that decide something later. Each is tied to a source that uses it.

Field	Why it decides something	The figure behind it
Species to the epithet, not "pine"	Canary Island pine and Italian stone pine are rated R in both columns and are not hosts in practice	UC IPM Pest Notes Table 2
County, and the date the zone map was consulted	Movement restrictions are county-level and the published map carries no date	Board of Forestry map, "data acquired from FRAP"
Count of flagged tips, and whether any canker is on the stem	Each lesion is a separate infection, and stem cankers follow multiple branch infections	UC IPM: the fungus is not known to move within the tree
Dead wood over the conductor, measured, with its position	This is the rule trigger, whatever killed the wood	PRC 4293: "weakened by decay or disease"
Whether the diagnosis is field or cultured	A definitive identification requires laboratory culture	UC IPM Pest Notes
Where the chips went	Uncomposted pine chips should not leave an infested county	Pitch Canker Task Force
Whether the log left the site, and under which treatment	One year stockpiled, 160 degrees Fahrenheit for 75 minutes, or fully debarked	Pitch Canker Task Force
Equipment set used, or sanitation performed	Tools used on diseased pines are contaminated	Lysol or 10 percent bleach, two minute soak

Two of those fields are unusual for a vegetation record, and both are there because of the same 1997 resolution. Where the chips went and how the log was treated are ordinarily nobody's business once the unit closes. Inside the Coastal Pitch Canker Zone of Infestation they are the only part of the work a state instrument actually reaches, and the office that can ask about them is the County Agricultural Commissioner rather than the utility or the Commission.

The rest of the file is an ordinary hazard record. A Monterey pine with a dead top over a 12 kV primary in Pacific Grove gets prescribed for the same reason a valley oak with a dead limb does, and the note that says "pitch canker" is explaining the cause rather than supplying the authority.

The Task Force wrote the sentence that keeps those two apart twenty-five years ago, and it still reads true: infection is not a sole reason to remove a tree, and a tree deemed hazardous for any reason should be removed regardless.

Frequently asked questions

Does the Pitch Canker Zone of Infestation change what a crew has to cut?

No. The resolution adopted June 4, 1997 authorizes the Director "to take actions which would control the movement, disposal and use of woody material infected with Pitch Canker," and it does that only "in the absence of action by other agencies." It sets no clearance distance, no inspection cycle and no prescription for a standing tree. The clearance obligations on a California pine are the same ones that apply to any other tree in the span: GO 95 Rule 35 and Public Resources Code section 4293. What the zone changes is where the wood can go afterward.

Which California pines are hosts?

Nearly all of them. UC IPM's Pest Notes rates knobcone, shore, Coulter, Aleppo, bishop, ponderosa, Monterey, gray and Torrey pines as susceptible in the field, along with Douglas-fir. Three commonly planted species are rated resistant in both greenhouse and field tests: Canary Island pine, Italian stone pine and Japanese black pine. The state's own detection records name Pinus attenuata, P. canariensis, P. contorta, P. halepensis, P. muricata, P. ponderosa, P. radiata, P. sabiniana, P. torreyana and Pseudotsuga menziesii as hosts, plus two grasses.

Is a pine with pitch canker a hazard tree?

Not on that basis alone. The Pitch Canker Task Force position paper, revised September 25, 2001, states that "Pitch canker infection is not a sole reason to remove a tree" and that the decision "should be based on more general criteria, such as safety." The same paper says large dead material should be mitigated as soon as possible. Dead branches over a conductor are reachable by GO 95 Rule 35 and by PRC 4293 whatever killed them, so the trigger a crew records is the dead wood, not the diagnosis.

Can the chips go in the truck?

The Pitch Canker Task Force guidance is that pine chips should not be transported out of infested counties unless composted, and that within an infested area chips are best used near the site of origin. It also records that chipping "has little impact on pathogen survival and may serve to more thoroughly distribute the pathogen among the chips." Because the pathogen is B-rated by CDFA, the local or destination County Agricultural Commissioner may restrict the movement of known infected host material. That office is the one to call before a load leaves a county.

Does the saw need to be sanitized between trees?

The Task Force guidance says tools and machinery used on diseased trees "WILL BECOME CONTAMINATED" and should be cleaned and sterilized before use on uninfected trees or in uninfested areas. It names Lysol or a 10 percent bleach solution, one part bleach to nine parts water, with a two minute soak time for bleach. It also offers the alternative most production programs will actually adopt, which is to reserve one set of equipment for infested areas and another for uninfested ones. It adds that there is little risk if contaminated tools are used only on dead trees or on non-pines.

Utility Line Clearance

Pre-Inspection

Emergency Services

QA/QC

LiDAR

Planning

Field Apps

Mobile Mapping

Careers

Blog