Which trees can you tap in California?

Bigleaf maple (Acer macrophyllum, native): Coast Ranges, Klamath–Siskiyou mountains, 'the northern Sierra Nevada' foothills; 'limited ... by drought to the south' Boxelder (California boxelder) (Acer negundo var. californicum, native): Central Valley and foothill riparian corridors Rocky Mountain maple (Acer glabrum, native): Sierra Nevada and northern mountains; small Norway, silver and sugar maple (Acer platanoides / saccharinum / saccharum, planted): Street and yard trees in cooler valley and foothill towns Black walnut (northern California walnut) (Juglans hindsii / J. nigra (planted), native): Central Valley riparian — no California tapping record found

California · beyond the maple belt

Can you make maple syrup in California?

MarginalMarginal: bigleaf maple grows from the North Coast through the Sierra foothills, and a 2025 Humboldt State study tapped 24 trees for six weeks — but sap flow fell as temperatures rose, the authors judged the species' southern range 'not suitable for large-scale commercial expansion' though possible for hobbyists, and no California producer was found.

Local timing guidance

No California-specific guidance; the Humboldt study collected 'from February to March 2025'. PNW hobby rule: leaf-fall to bud-break, best 'in January and February'.

Source: Cal Poly Humboldt 2025 (VERIFIED, study dates only); Raven's Roots 2016 (PRACTITIONER)

Trees

Tappable trees in California

Tappable tree species in California
Species	Status	Where
Bigleaf mapleAcer macrophyllum	native	Coast Ranges, Klamath–Siskiyou mountains, 'the northern Sierra Nevada' foothills; 'limited ... by drought to the south'USFS FEIS (CA in states list)
Boxelder (California boxelder)Acer negundo var. californicum	native	Central Valley and foothill riparian corridorsUSFS FEIS ('var. californicum -- California')
Rocky Mountain mapleAcer glabrum	native	Sierra Nevada and northern mountains; smallUSFS FEIS (CA in STATES list)
Norway, silver and sugar mapleAcer platanoides / saccharinum / saccharum	planted	Street and yard trees in cooler valley and foothill townsRECALL
Black walnut (northern California walnut)Juglans hindsii / J. nigra (planted)	native	Central Valley riparian — no California tapping record foundRECALL

Who already does it

Sugaring in California, documented

Humboldt State (Cal Poly Humboldt) undergraduate study, spring 2025: 'Over six weeks of collection from February to March 2025, we tapped 24 bigleaf maple trees in Humboldt County'; sap yield correlated negatively with the day/night temperature spread (r = −0.91); 'not suitable for large-scale commercial expansion, it may support small-scale, hobbyist operations'
Reinhart, Ramos-Cool & Richardson, Cal Poly Humboldt Digital Commons · VERIFIED
Pacific Northwest hobby guide (applies to the North Coast): collect 'from the time the leaves fall off the trees, until the leaves start budding ... the best flows seem to happen in January and February'
Raven's Roots Naturalist School (Jan 2016) · PRACTITIONER
No California commercial bigleaf producer found; West Coast coverage names only Washington and BC producers
Modern Farmer 2020; session search log · PRACTITIONER

Cautions

What local sources warn about

Warmth kills flow: in Humboldt 'lower and more stable temperatures correlat[ed] with higher sap production'; the southern range is for hobbyists only. (Cal Poly Humboldt 2025 (VERIFIED))
Bigleaf sap is ~1–1.5% sugar (WSU) — 80–100 gallons per gallon of syrup. (WSU Extension (VERIFIED, WA))
Young smooth-barked stems (4–18 in) tap more easily than old furrowed trunks; collect every 2–3 days at most in mild weather. (Raven's Roots 2016 (PRACTITIONER))

Where to look

Likely sugaring country

Arcata / Eureka (Humboldt County)
Site of the only California bigleaf tapping study
Nevada City / Grass Valley (Nevada County)
Northern Sierra foothills with bigleaf maple and real winter freezes
Mount Shasta / Yreka (Siskiyou County)
Klamath–Siskiyou bigleaf country with the state's most reliable freeze-thaw

Minor place. Searches: 'California maple syrup tapping bigleaf maple OR black walnut California producer sap season Sierra'; 'California maple syrup producer tapping bigleaf Humboldt/Mendocino/Sierra'. No producer found.

FAQ

Sugaring in California: questions

Can you tap maple trees in California?: Marginal. Marginal: bigleaf maple grows from the North Coast through the Sierra foothills, and a 2025 Humboldt State study tapped 24 trees for six weeks — but sap flow fell as temperatures rose, the authors judged the species' southern range 'not suitable for large-scale commercial expansion' though possible for hobbyists, and no California producer was found.
When do you tap maple trees in California?: No California-specific guidance; the Humboldt study collected 'from February to March 2025'. PNW hobby rule: leaf-fall to bud-break, best 'in January and February'. (Cal Poly Humboldt 2025 (VERIFIED, study dates only); Raven's Roots 2016 (PRACTITIONER))
Which trees can you tap in California?: Bigleaf maple (Acer macrophyllum, native): Coast Ranges, Klamath–Siskiyou mountains, 'the northern Sierra Nevada' foothills; 'limited ... by drought to the south' Boxelder (California boxelder) (Acer negundo var. californicum, native): Central Valley and foothill riparian corridors Rocky Mountain maple (Acer glabrum, native): Sierra Nevada and northern mountains; small Norway, silver and sugar maple (Acer platanoides / saccharinum / saccharum, planted): Street and yard trees in cooler valley and foothill towns Black walnut (northern California walnut) (Juglans hindsii / J. nigra (planted), native): Central Valley riparian — no California tapping record found

Nearby

Other places beyond the belt

LuckySap · free on iPhone & Android

Try a season where you are

LuckySap turns the forecast for any spot into a day-by-day sap outlook and logs every collection and boil. Free on iPhone and Android.