Ground cover

Zone 0 mulch rules in California: what the adopted rule bans and what to put down instead

Fact-checked August 19, 2026·Sources at the end of this article

What the regulation actually says about mulch

On mulch, California's statewide Zone 0 regulation does not hedge. Section 1298.04(b)(1) of Title 14, the version for Very High Fire Hazard Severity Zones in Local Responsibility Areas, reads:

"Except as set forth herein, no Combustible materials are permitted within the full 5 feet of Zone 0. This includes, but is not limited to: fallen leaves and tree needles; Combustible mulches, including bark and woodchips; and other Combustible debris."

Board of Forestry and Fire Protection, 14 CCR §1298.04(b)(1), July 2026 draft rule text and carried unchanged into the August 19, 2026 package the Board approved. The corresponding State Responsibility Area provision sits at §1299.03(d)(1).

That is a flat prohibition. Once the regulation takes effect, bark, woodchips, and every other combustible mulch are barred from the zone measured 5 feet out from the exterior wall, roof, attached deck, stairs, or pergola, or to the property line, whichever comes first. The rule covers all property owners in State Responsibility Areas (SRAs) and in Very High Fire Hazard Severity Zones within Local Responsibility Areas (LRAs); if you're not sure where your parcel sits, start with does Zone 0 apply to my home.

Note the timing, because it is the whole story right now. The Board adopted this language on August 19, 2026, so its content is settled. It is not yet in effect: the package still has to clear the Office of Administrative Law, including a five-day public comment period, and be published by the Secretary of State. No statewide compliance clock is running, because every deadline in the rule keys off an effective date that does not yet exist. The only Zone 0 rules enforceable today are local ordinances.

One caution about the exact wording quoted here and below. The package published in the Board's August 19 binder is the pre-meeting deliberative draft. Any amendment made from the floor would not appear in it, and no certified "as adopted" text has been published yet. Treat provision-level wording as the package the Board acted on, with the certified text still pending.

The one exception: erosion control

The regulation carves out exactly one situation where mulch may stay, and it is narrower than most coverage suggests:

"Inspectors may allow temporary exceptions to limitations on mulches to prevent erosion during new or continuing construction and during emergencies."

Board of Forestry, 14 CCR §1298.04(b)(1)(A), July 2026 draft rule text, unchanged in the August 19, 2026 package; a corresponding exception appears in the State Responsibility Area version at §1299.03.

Read the qualifiers. The exception is temporary, runs through an inspector's discretion, and applies during construction and emergencies, not as a general landscaping allowance. A permanent bark bed on a slope next to the house is not what this language protects.

When the mulch has to go

The regulation phases in by structure type. Mulch sits in the first wave.

The Board's own summary describes Phase 1 this way:

"PHASE 1 (Implemented within the first 3 years): Includes removing combustible items such as firewood, dead leaves and branches, mulch, and wood chips within 5 feet of the structure."

Board of Forestry, Summary of Draft Zone 0 Regulation Language, July 2026. The rule text implements this at §1298.04(c)(3); §1298.04(c)(1) requires new construction to comply on the effective date.

One detail changed in August, and it matters if you are reading the July summary. Roof and gutter debris moved out of the three-year tier: §1298.04(c)(2) now requires existing occupied structures to comply with (b)(2), the roof and gutter provision, together with the tree items at (b)(5)(A), (B) and (C), upon the effective date. Ground-level combustibles, mulch included, stay in the three-year tier, which now reads "(b)(1) and (b)(3)-(4)" rather than the older "(b)(1)-(4)". So the leaves on your roof and in your gutters come due immediately; the bark bed at the foundation gets three years.

No calendar dates exist yet: every deadline runs from an effective date that does not exist. Staff said they would submit the package to the Office of Administrative Law as an emergency rulemaking under AB 1455 (2025), and expected the rules could become effective as early as September 2026, which would put the Phase 1 deadline for existing homes roughly in 2029. The full phase-in picture is in our timeline and enforcement guide.

Why mulch is the classic ember bed

Mulch earns its place at the top of the prohibition list. In 2022, NIST published Technical Note 2228, "Wind-Driven Fire Spread to a Structure from Fences and Mulch": 187 field experiments in winds of 6–14 m/s. Nearly all fence-and-mulch combinations generated firebrands capable of igniting downwind spot fires, and every wood fence with mulch at its base caused spot fires in the target mulch bed placed at the structure's base. NIST's announcement put it plainly:

"Flames rushed along mulch lining the base of fences, and infernos quickly swallowed up pairs of fences when they burned in close proximity to each other."

NIST news release, "NIST Study Finds Wildfire Hazards in Residential Fences and Mulch Beds," August 2022.

That is the mechanism: embers land in the mulch, the mulch bed ignites, and if a wood fence runs through it, the burning bed feeds the fence line all the way to the house. The Board of Forestry's Zone 0 FAQ uses the wick metaphor for exactly this chain, advising owners with a wood fence to upgrade the five feet touching the house with a noncombustible panel to "break the wick of fire, should the fence ignite in the future." The same FAQ calls Zone 0 "the most important area to keep clear of combustible items such as woody mulch and plants." We cover the fence half of that equation in why fences burn homes and the California Zone 0 fencing guide.

What goes in its place

Here is something most coverage gets wrong: the rule text names no approved ground covers. It prohibits combustible materials and defines "Noncombustible" as materials passing ASTM E136, a furnace test that measures whether a material itself can burn. The commonly cited replacement lists come from two other published sources, and they agree with each other:

• IBHS Wildfire Prepared Home standard (2025), section 2.2.1 requires removing all combustible groundcover ("e.g., wood and rubber mulch and exposed weed cloth") within 5 feet down to bare mineral soil, and notes: "Noncombustible hardscape materials (e.g., gravel, pavers, river rocks, decomposed granite, steppingstones, and concrete) are permitted."
• Berkeley's ordinance (Fire Code section 4907.6): "Hardscape materials, such as gravel, pavers, concrete, and other noncombustible mulch materials are permitted."

So the working menu is: rock and river rock, gravel, decomposed granite (DG), pavers, concrete, and plain bare soil. All are mineral materials that give an ember nothing to catch; which one fits is a drainage, traffic, and looks decision the rules leave entirely to you.

Where mulch bans are already in force: San Diego and Berkeley

Two California cities did not wait for Sacramento, and both treat mulch the same way the state rule does.

San Diego. Under SDMC §512.0604, Zone 0 requirements applied to all new structures seeking a building permit on or after February 28, 2026, and apply to existing structures one year later. The city's Zone 0 Guidelines for Existing Structures (Rev. 4/22/2026) state that Zone 0 "is intended to function as a non-combustible ember-resistant area," and the first condition in section 4.1 is blunt: "Combustible mulch is prohibited." The city will prioritize education and voluntary compliance in year one; enforcement begins on or after February 28, 2027, and the guidelines note they "are not enforceable until February 28, 2027, and are subject to change." Full detail in our San Diego Zone 0 guide.

Berkeley. The EMBER ordinance took effect January 1, 2026 in the Grizzly Peak and Panoramic hillside mitigation zones. Its prohibited-combustibles list expressly names "wood mulch products" alongside vegetation, firewood, synthetic lawn, and combustible fencing. And, as quoted above, the ordinance expressly permits gravel, pavers, and concrete in their place. Enforcement had a grace period, with inspections reported ramping up through 2026; confirm current practice with Berkeley Fire. Other jurisdictions with their own rules are tracked in local Zone 0 ordinances.

The cost picture

We won't quote dollar figures; honest ones depend on your square footage, slope, and zip code. But the qualitative point stands: of all the categories Zone 0 touches (fencing, decks, outbuildings, vegetation), ground cover is generally the cheapest to fix. The materials are commodity landscape products. The labor is rake-and-wheelbarrow work rather than a skilled trade, and nothing gets demolished. For many homes the whole job is a weekend.

There is also an insurance angle, in force today and separate from Zone 0. Under the Safer from Wildfires regulation (10 CCR §2644.9, operative since October 2022), insurers that price California homeowners policies on wildfire risk must reflect enumerated mitigation measures in their rating plans. One of them is "Clearing of vegetation, debris, mulch, stored combustible materials ... within five (5) feet of the Building Being Evaluated." That regulation binds insurers, not homeowners: it requires carriers to offer a credit, does not require you to touch your yard, and promises no particular savings. See the twelve Safer from Wildfires measures.

What this means for you

As of August 19, 2026, here is the practical read:

• Statewide, nothing is required yet. The Board adopted the mulch prohibition on August 19, 2026, but it does not bind anyone until the Office of Administrative Law finishes review and the Secretary of State publishes it. Once effective, existing homes get three years.
• If you're in San Diego's Very High zones or Berkeley's hillside zones, the rules are real now: new San Diego structures since February 28, 2026, existing ones on a clock toward February 2027; Berkeley's covered zones since January 1, 2026.
• The direction of travel is unambiguous. The adopted state text, both in-force city ordinances, the IBHS voluntary standard, and the insurance regulation's mitigation list all treat combustible mulch in the first five feet as the thing to remove. Work done now anticipates a requirement whose content is settled, even though its start date is not.
• Measure the five feet honestly. The zone runs from the exterior wall, roof edge, attached deck, stairs, or pergola, not just from the foundation. The August package narrowed the carve-out for noncombustible features to patios alone, so a metal or concrete attached deck now extends the zone too, and mulch under and around any attached deck counts.
• Photograph before and after. Clearing combustibles within five feet is a mitigation measure your insurer's rating plan must recognize, and documentation is how the work gets counted.

Ground cover is one item on a longer list. Walk the whole first five feet with our Zone 0 checklist, and see plants and vegetation in Zone 0 for the far more nuanced rules on living plants.