2026–27 Planting Forecast

When to sow, every region

Best sowing windows for the 2026–27 season

Solid bars show the main sowing windows. Striped bars show dormant sowing, when seed goes onto cold ground and waits for spring. Outlined bars show the spring window. The dashed bar shows how far the Southern California window could stretch in a strong El Niño winter. Each region’s forecast below explains the timing. Jump to a forecast in the table of contents.

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How this forecast works

How we choose the planting windows

Native species have different needs, and growing conditions vary within each region. We use the same regions as our native wildflower mixes, with separate guidance where climate or elevation changes the planting season.

We look at soil temperature, moisture after sowing, and freezing weather. The thresholds below are working settings in our forecast tool, chosen from published planting guidance and our growing experience. They help us estimate regional windows; individual species may need different conditions.

Fall, dormant and spring sowing

• Fall sowing (Pacific Northwest west of the Cascades, California, Southeast, low desert): cool-season seed sprouts with fall and winter moisture and grows toward spring bloom. UC Davis Arboretum recommends October–November for the California natives it describes; Xerces lists October–January for California annual wildflowers.
• Dormant sowing (Midwest, Northeast, West, inland Northwest): seed goes onto soil that stays cold enough to delay germination until spring. Winter can provide the cold, moist treatment some species need, and freeze-thaw cycles help seed make contact with the soil.
• Spring sowing (cold regions and the Northwest): a second window as soil warms toward 50°F and spring moisture arrives. Seed that needs cold treatment may need it before planting. Xerces notes that spring sowing can favor grasses over wildflowers; we generally favor fall or dormant sowing for these mixes.

Quickstart

• Clear weeds and grass; lightly rake the soil surface.
• Mix seed with clean sand or rice hulls so it spreads evenly.
• Scatter by hand, then press seed against the soil by walking or rolling over it. Keep small seed at or near the surface, following the mix’s sowing-depth instructions.
• For seed germinating now, water gently as needed to keep the seed zone moist. As seedlings establish, gradually water less often and soak farther into the root zone. Rain counts; check the soil rather than following a fixed schedule. Dormant seed waiting through winter does not need the same watering routine.

Methodology

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California

Valley, coast, Bay Area and Southern California

Best sowing

November 1 to late January for the valley and coast · October through mid-February in the Bay Area · mid-November through January in Southern California, possibly into mid-March in a strong El Niño winter

Covers

California

Sample cities

Sacramento, Modesto (valley) · Salinas, Arcata (coast) · San Francisco · Los Angeles, San Diego

Valley and coast

Sow into the first real rains

Central Valley Mix → Coastal Mix →

Our Central Valley averages show soil near 70°F in October, falling to 57°F in November as monthly precipitation rises from 1.7 to 2.7 inches. December and January each average about 5 inches. Salinas runs cooler, at 63°F in October, but its rain arrives later too. Sow as the soil cools and winter rain arrives.

Month by month · Valley (Sacramento) and Coast (Salinas)

Month	Valley soil	Valley precip.	Valley ≤28°F	Coast soil	Coast precip.	Coast ≤28°F
Oct	70°F	1.7"	—	63°F	0.8"	—
Nov	57°F	2.7"	—	56°F	2.1"	—
Dec	49°F	5.1"	0.3	52°F	4.0"	—
Jan	49°F	5.1"	0.1	51°F	4.6"	—
Feb	51°F	4.4"	0.2	52°F	3.2"	—
Mar	55°F	4.2"	—	54°F	4.0"	—
Apr	62°F	1.5"	—	57°F	1.3"	—
May	72°F	0.8"	—	60°F	0.6"	—

Our advice

• Prepare beds in fall; aim to sow ahead of a soaking November rain, allowing for runoff.
• Coast: begin late October if a storm is in the forecast.
• Valley: aim for mid-November to mid-December.
• Sowing through January still works, with a shorter run before spring heat.
• Where this varies: the foothills, the Sierra and the desert edge follow their own calendars. This section covers the valley, the coast, the Bay Area and Southern California’s coastal plain.

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El Niño SF Bay Forecast

What a strong El Niño winter means for sowing

Shop the SF Bay Area Mix →

NOAA’s October 8, 2026 update has an El Niño Advisory in effect, with Niño-3.4 sea surface temperatures about 2.1°C above normal and a greater than 83% chance of strong-to-very-strong El Niño through January–March 2027. We compared that outlook with 76 San Francisco wet seasons, from 1950–51 through 2025–26, grouping October–April rainfall by winter El Niño strength.

What the record shows · San Francisco, October–April, 1950–51 through 2025–26

Winter type	Winters	Avg precip.	Rainy days	1"+ storm days	Dec–Feb	Mar–Apr
Strong El Niño	7	26.1"	53	4.3	15.2"	6.4"
All El Niño	25	19.9"	42	3.2	12.2"	4.5"
Neutral	25	16.6"	34	2.6	9.8"	4.0"
La Niña	26	16.6"	37	2.1	8.8"	4.4"
All other winters	51	16.6"	35	2.3	9.3"	4.2"

In our analysis, the seven strong El Niño winters averaged 26.1 inches of rain, compared with 16.6 inches across the 51 neutral and La Niña winters. They averaged 4.3 days with at least an inch of rain, versus 2.3. The season’s first accumulated inch arrived around October 27 in strong El Niño winters and November 8 in the other winters.

Across all 25 El Niño winters in our analysis, 64% exceeded the long-term median rainfall, compared with 43% of neutral and La Niña winters. El Niño winters were more often wetter than the median.

Month by month · San Francisco and Sacramento (typical year)

Month	SF soil	SF precip.	SF ≤28°F	Sacramento soil	Sacramento precip.	Sacramento ≤28°F
Oct	67°F	1.2"	—	70°F	1.7"	—
Nov	58°F	2.5"	—	57°F	2.7"	—
Dec	52°F	5.2"	—	49°F	5.1"	0.3
Jan	52°F	5.0"	—	49°F	5.1"	0.1
Feb	53°F	3.8"	—	51°F	4.4"	0.2
Mar	55°F	4.0"	—	55°F	4.2"	—
Apr	60°F	1.3"	—	62°F	1.5"	—
May	65°F	0.7"	—	72°F	0.8"	—

Our take

If this winter follows the wetter pattern, rain could reduce the need for supplemental watering. Heavy storms could also wash seed off bare or sloping ground. Sow ahead of rain that can soak in, protect runoff-prone beds, and check moisture between storms. Seasonal rainfall totals cannot tell us how evenly that water will arrive.

• Sow any time from October through mid-February. Earlier gives seed more time to settle before the biggest storms.
• Aim to sow just ahead of a forecast soaking rain, and press the seed in firmly.
• On slopes or bare runoff paths, hold off when a 1-inch-plus storm is in the forecast.

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Southern California

Spotlight on Los Angeles and San Diego

Shop the California Mix →

Los Angeles and San Diego soil averages about 75°F in October, 66°F in November, and the high 50s in December. Rain increases from roughly half an inch in October to 1.4–1.6 inches in November and 2.2–3.7 inches in December. We recommend mid-November through January to catch that cooler, wetter stretch. Los Angeles averages more December rain than San Diego.

Month by month · Los Angeles and San Diego

Month	LA soil	LA precip.	LA ≤28°F	SD soil	SD precip.	SD ≤28°F
Oct	75°F	0.6"	—	74°F	0.5"	—
Nov	66°F	1.6"	—	66°F	1.4"	—
Dec	58°F	3.7"	—	59°F	2.2"	—
Jan	56°F	3.6"	—	57°F	2.9"	—
Feb	58°F	3.2"	—	59°F	2.2"	—
Mar	61°F	3.1"	—	62°F	2.5"	—
Apr	68°F	0.7"	—	68°F	0.8"	—
May	73°F	0.4"	—	72°F	0.5"	—

How we’d sow it

• Aim for mid-November onward, when cooler soil and more rain overlap in these averages.
• Sow ahead of the first December storm.
• Keep sowing through January; water between storms if the seedbed starts to dry.
• If this winter follows the strong El Niño pattern, the window could stretch into mid-March. In past strong El Niño winters, February and March brought most of the extra rain.

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Pacific Northwest

Washington, Oregon and northern Idaho: west-side rain, inland cold

Best sowing

Mid-October through November west of the Cascades · dormant sowing mid-November into January inland · March to mid-April in spring

Covers

Washington, Oregon, northern Idaho

Sample cities

Portland, Seattle (west) · Spokane (inland)

Shop the Pacific Northwest Mix →

Portland’s October–November soil cools from 56°F to 48°F as monthly precipitation rises from 5.7 to 7.7 inches. Fall seed gets both warmth for germination and returning rain. Spokane reaches 40°F soil and about 10 nights at or below 28°F in November, so inland sowing shifts to seed waiting through winter. West of the Cascades, spring brings another stretch of cool soil and rain before the dry summer.

Month by month · west (Portland) and inland (Spokane)

How we’d sow it

• West of the Cascades: aim for mid-October through November, with enough moisture to support germination.
• Eastern Washington and Oregon, northern Idaho: plan for dormant sowing from mid-November into January, once sustained cold arrives and seed can reach the soil.
• Missed fall? March to mid-April is a strong second window on the west side.
• Where this varies: higher elevations and rain-shadow areas run colder and drier, so treat them like the inland calendar.

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Midwest

Prairie country: sow dormant, then again in spring

Best sowing

Dormant sowing mid-November into early January · spring sowing April to mid-May

Covers

Illinois, Indiana, Iowa, Kansas, Michigan, Minnesota, Missouri, Nebraska, Ohio, Wisconsin

Sample cities

Des Moines, Columbus

Shop the Midwest Mix →

By November, soil averages 44°F in Des Moines and 47°F in Columbus, with about 6–9 nights at or below 28°F. Wait for sustained cold so dormant-sown seed stays dormant through winter. Des Moines is drier, generally under 2 inches of monthly winter precipitation, while Columbus averages 3–4 inches. Spring brings warmer soil and more moisture; May averages nearly 5 inches of precipitation in both cities.

Month by month · Des Moines and Columbus

Our advice

• Plan to sow from mid-November into early January, once soil stays cold enough to delay germination and seed can reach the ground.
• A thin snow layer can work if seed can reach the soil as it melts. Avoid deep snow, ice and runoff.
• Spring: sow in April and into May once soil is workable.
• Where this varies: some prairie species need no cold treatment; others need a specific period of cold and moisture. Dormant sowing can provide that treatment naturally for species with those requirements.

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Northeast

New England to the Mid-Atlantic: dormant sowing as sustained cold arrives

Best sowing

Dormant sowing mid-November into early January (Mid-Atlantic into December) · spring sowing early April to late May

Covers

Connecticut, Delaware, DC, Maine, Maryland, Massachusetts, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island, Vermont, West Virginia

Sample cities

Albany, Philadelphia

Shop the Northeast Mix →

Albany cools sooner than Philadelphia: November soil averages 44°F versus 51°F, with about 7 nights at or below 28°F versus 2. Dormant sowing therefore starts earlier upstate. The difference carries into spring: Philadelphia soil averages 54°F in April, while Albany is still 47°F and reaches 57°F in May. Monthly precipitation stays around 3–5 inches, including the water equivalent of snow.

Month by month · Albany and Philadelphia

How we’d sow it

• New England and upstate New York: sow from mid-November onto cold soil.
• Mid-Atlantic: aim for late November through December, once soil stays cold enough to delay germination.
• Spring: sow in April once soil is workable; early May for northern New England.
• Where this varies: coastal areas and cities run warmer than Albany, and the mountains run colder.

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Southeast

From the Carolinas to the Gulf: fall and winter windows

Best sowing

Mid-October to early December (Piedmont and upper South) · fall through January (Florida, varying north to south) · winter (Gulf Coast, locally adjusted) · mid-February through March (spring)

Covers

Alabama, Arkansas, Florida, Georgia, Kentucky, Louisiana, Mississippi, North Carolina, South Carolina, Tennessee, Virginia, eastern Texas

Sample cities

Atlanta, Raleigh · Orlando · Austin

Shop the Southeast Mix → Florida Mix → Texas Mix →

Atlanta and Raleigh soil cools from 65–68°F in October to 55–58°F in November, with about 3 inches of monthly precipitation. Fall offers time for seedlings to establish before colder weather. Some wildflowers form winter rosettes; seed needing cold may wait until spring. Florida’s season shifts from fall in the north to early winter in the south. The late-winter window catches warming soil before summer heat, with more rain in Atlanta than Raleigh.

Month by month · Atlanta and Raleigh

Florida and eastern Texas

Our advice

• Piedmont and upper South: aim for mid-October through early December, with time for fall-germinating species to establish before damaging cold.
• Florida: mid-September–mid-October in the north, mid-October–December in central Florida, and November–January in the south, following Florida Wildflower Foundation guidance. Gulf Coast timing depends on location and mix.
• Eastern Texas: November and December.
• Missed fall? Mid-February through March still works before the heat.
• Where this varies: the mountains of the Carolinas, Tennessee and Virginia behave more like the Northeast.

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Southwest

Arid country: sow ahead of the rains

Best sowing

November through December (low desert cool-season seed) · late fall for species that need cold, moist conditions before germinating · May–June ahead of local summer rains for warm-season species

Covers

Arizona, New Mexico, Oklahoma, western Texas, southern Utah and Colorado

Sample cities

Phoenix, Albuquerque

Shop the Southwest Mix → Texas Mix →

Moisture is the main constraint in these sample cities. Phoenix soil averages 84°F in October, 70°F in November and 60°F in December, with roughly an inch of monthly winter precipitation. We recommend November–December for cool-season wildflowers, with supplemental water when rain falls short. Albuquerque is drier, with less than an inch of monthly winter precipitation and about 12–19 nights at or below 28°F in December and January. There, distinguish seed that needs winter cold from warm-season species suited to summer rain. Xerces lists February–May for Southwest wildflowers; Arizona guidance also supports fall sowing for cool-season desert flowers. The different windows reflect different species and climates.

Month by month · Phoenix and Albuquerque

Our advice

• Low desert (Phoenix, Tucson): sow in November and December. For seed germinating now, water gently as needed to keep the seed zone moist, then gradually space waterings farther apart and soak farther into the root zone as seedlings establish.
• High desert (New Mexico, southern Colorado and Utah): sow species that need cold, moist conditions in late fall onto cold ground. Sow summer germinators in May–June ahead of local summer rains, adjusting for elevation and the arrival of rain.
• Oklahoma and western Texas: dormant sowing in late November, or spring with April rains.

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West

Mountains and high plains: dormant sowing and spring moisture

Best sowing

Dormant sowing mid-November to mid-January · spring sowing mid-April through May

Covers

Colorado, Idaho, Montana, North Dakota, South Dakota, Utah, Wyoming, northern Nevada, eastern Washington and Oregon

Sample cities

Denver, Boise, Reno

Shop the West Mix → Nevada Mix →

Denver’s November soil averages 44°F, with about 16 nights at or below 28°F. Winter precipitation is around an inch a month or less, making snowmelt and spring moisture valuable for dormant-sown seed. Boise gets more winter precipitation, around 2 inches a month in December–February. By April, soil in both cities reaches about 50°F; Denver’s precipitation rises to 3.5 inches in May.

Month by month · Denver and Boise

How we’d sow it

• Sow from mid-November onto cold, bare ground, ideally just before a snow.
• Press seed in firmly and protect exposed beds from wind and runoff.
• Spring: sow from mid-April into May, timing to the spring storms.
• Where this varies: timing shifts with elevation, and mountain towns can run weeks behind Denver.

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All regions at a glance

Soil temperature and monthly rain, side by side

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Behind the numbers

Data, calculations and planting guidance

Weather data

• Source: ERA5 and ERA5-Land reanalysis from the European Centre for Medium-Range Weather Forecasts, retrieved through Open-Meteo. Reanalysis combines observations and models to estimate past weather across a grid. ERA5 cells are roughly 25 km across; ERA5-Land cells are roughly 11 km across.
• Period: daily values for 2016 through 2025, averaged by calendar day. Soil curves are smoothed over 7 days.
• Sample cities: Portland, Seattle and Spokane (Pacific Northwest); San Francisco, Sacramento, Modesto, Salinas, Arcata, Los Angeles and San Diego (California); Des Moines and Columbus (Midwest); Albany and Philadelphia (Northeast); Atlanta, Raleigh, Orlando and Austin (Southeast); Phoenix and Albuquerque (Southwest); Denver, Boise and Reno (West).
• Soil temperature represents the 7–28 cm layer, about 3–11 inches deep. Precipitation is summed by week or month. Freeze counts are the average number of days per month with minimum air temperature at or below 28°F. Fractional counts are averages across years. A dash marks a value displayed as zero; it does not establish that a freeze is impossible.

El Niño comparison

• Rain: reanalysis at the San Francisco grid point, October 1–April 30, for each of the 76 winters from 1950–51 through 2025–26. These are gridded estimates, not totals from a San Francisco rain gauge.
• Classifying winters: we group winters by their December–February Oceanic Niño Index: El Niño at +0.5 or higher, strong at +1.5 or higher, La Niña at −0.5 or lower, and neutral between those thresholds. This single-season grouping is our comparison method, rather than NOAA’s full event definition. The seven strong winters are 1957–58, 1972–73, 1982–83, 1991–92, 1997–98, 2015–16 and 2023–24.
• First inch of rain: the date each season’s rain total first reaches one inch, counting from October 1.
• Storm days: days with at least one inch of rain. Rainy days: days with at least a tenth of an inch.

Sowing windows

We choose the windows by comparing the three working rules with regional weather patterns, published planting guidance, and our growing experience. The dates are regional estimates. We have not modeled the requirements of every species in each mix.

Sources

• NOAA Climate Prediction Center, ENSO diagnostic discussion (October 8, 2026)
• NOAA Oceanic Niño Index
• Open-Meteo historical weather API (ERA5 and ERA5-Land)
• UC Davis Arboretum and Public Garden, California native wildflower seeds
• Xerces Society, Establishing Pollinator Meadows from Seed
• Prairie Moon Nursery, Cultural Guide (germination codes and fall sowing)
• Farmers for Monarchs, Dormant seeding
• Lady Bird Johnson Wildflower Center, when to plant wildflower seeds
• Water – Use It Wisely, fall planting wildflowers (Arizona)
• Florida Wildflower Foundation, Starting a Wildflower Garden from Seed
• University of Arizona Cooperative Extension, Wildflowers (2023)

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