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Alameda County, CA — Planting Guide

Alameda County is in USDA Zone 9b. The average last spring frost is January 18 and the first fall frost is December 12, giving you a growing season of approximately 329 days.

At an elevation of 379 ft, Alameda County receives approximately 16.4 in of rainfall annually. Summer highs average 97°F with winter lows around 56°F. The predominant soil type is Loam.

Based on 13 years of NOAA climate station data, the last frost date here varies by 79 days year to year — ranging from January 5 in warm years to March 24 in cold years. The growing season is trending longer by about 25.71 days per decade. Alameda County scores 43/100 (Moderate) on the Microclimate Index.

🌡️ Zone

9b (25°F to 30°F min)

❄️ Last Frost

January 18

🍂 First Frost

December 12

📅 Growing Season

329 days

⛰️ Elevation

379 ft

🌧️ Annual Rainfall

16.4 in

Alameda County, CA Year-round
328 days
Last Spring Frost January 18
328 growing days
First Fall Frost December 12

Monthly Watering Calendar

When you'll need to water your garden — based on average monthly rainfall vs. the ~1 inch/week most gardens need.

1"/wk 0" 1.3" 2.5" 3.8" 5" Jan 3" +0.7" Feb 3.6" +1.7" Mar 2.6" +3.1" Apr 1.2" +3.9" May 0.4" +4.2" Jun 0.1" +4.3" Jul 0" +4.3" Aug 0" +4.1" Sep 0.2" +3.7" Oct 0.6" +2.8" Nov 1.5" Dec 3.1"
Rainfall sufficient Supplemental water needed Heavy watering required - - - 1"/week garden need
View detailed monthly data
MonthAvg RainfallRainy DaysExtra Water NeededWatering Effort
Jan 3 in 10 days None
Feb 3.6 in 10 days 0.7 in Moderate
Mar 2.6 in 7 days 1.7 in High
Apr 1.2 in 4 days 3.1 in Critical
May 0.4 in 1 days 3.9 in Critical
Jun 0.1 in 0 days 4.2 in Critical
Jul 0 in 0 days 4.3 in Critical
Aug 0 in 0 days 4.3 in Critical
Sep 0.2 in 0 days 4.1 in Critical
Oct 0.6 in 2 days 3.7 in Critical
Nov 1.5 in 5 days 2.8 in High
Dec 3.1 in 9 days None

Annual total: 16.3 in. Water needs vary by crop — tomatoes need ~1.2"/week while herbs like rosemary need only 0.3"/week. Check individual plant pages for crop-specific water budgets that factor in your county's rainfall and soil drainage.

Alameda County Soil Profile

Soil Type

Loam

Soil pH

6.3-7.7

Drainage

Well Drained

Frost Risk Probability

Based on 13 years of NOAA weather station data from 3 stations

Too early frost risk Safe to Plant Jan 18 → Dec 12 329 frost-free days Protect crops frost returns Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Safe: Mar 24 Protect by: Dec 24

Beginners: Plant frost-sensitive crops (tomatoes, peppers, squash) after the "Safe" date on the left. Harvest or cover them before the "Protect by" date on the right. Hardy crops (lettuce, peas, kale) can go in the yellow transition zones.

How to read this table: "Conservative" means you're safe from frost 9 out of 10 years — best for beginners and frost-sensitive crops. "Average year" is the typical date. "Aggressive" means only 1 in 10 years is that warm — experienced gardeners with frost protection can try these dates.

Planting Strategy Last Spring Frost First Fall Frost Frost-Free Days
Conservative (safest) Mar 24 Dec 24 275 days
Cautious Feb 17 Dec 19 305 days
Average year Jan 18 Dec 12 328 days
Optimistic Jan 14 Dec 5 325 days
Aggressive (risky) Jan 5 Nov 22 321 days
📊
How predictable are frost dates here?

Not very — frost dates can vary by ±79 days year-to-year. Use the "Conservative" row in the table below, and keep row covers handy for surprise late frosts.

🌱
Is the growing season changing?

Yes — growing seasons are getting longer here (about 25.7 days per decade). Spring is arriving earlier than it used to. Good news for gardeners.

Gardening Difficulty Score

43 Moderate
Frost Timing Risk
10.0/10
Drought Risk
7.5/10
Soil Difficulty
1.0/10
Altitude Challenge
0.0/10
Climate Shift
10.0/10
Rainfall Challenge
5.4/10

Alameda County presents some gardening challenges. Choose adapted varieties and plan around frost dates.

Zone 9b Frost Countdown
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Last Frost: Jan 18 First Frost: Dec 12

Local Gardening Help in Alameda County

Free expert help is closer than you think. Your county's cooperative extension office connects you with trained gardeners, soil testing labs, and local programs — all specific to Alameda County's climate and soil.

County Extension Office

Alameda County University of California Cooperative Extension Extension Office

Phone: 530-750-1200

Visit Extension Office Website →

Extension offices are run by land-grant universities and funded by the USDA. Their advice is free, research-based, and tailored to your county's specific conditions.

Master Gardener Program

Free gardening help from trained volunteers

Master Gardeners are community volunteers who complete 40–60 hours of university horticultural training. They answer gardening questions, diagnose plant problems, and offer workshops — all free.

Find Master Gardeners in CA →

Many extension offices run a Master Gardener hotline where you can call or email with photos of plant problems for free diagnosis.

Soil Testing

Available through your extension office

Before amending your soil, get it tested. Your extension office offers soil testing (typically $10–$25) that tells you exact pH, nutrient levels, and amendment recommendations specific to what you want to grow.

Request a Soil Test →

Services Available in Alameda County

Soil testing Pest management Water-wise gardening Master Gardener hotline
Finding local nurseries & garden centers in Alameda County

Why Buy Local

Local nurseries carry plants that are proven to grow in your area. Staff can give you advice specific to Alameda County's soil and climate that big-box stores can't. Plants from local growers are typically hardier because they're already acclimated to your zone.

How to Find Them

Search for "nurseries near Alameda County CA" or "garden center Alameda County" on Google Maps. Also check with your extension office — they often maintain lists of reputable local nurseries and plant sales.

Community gardens & gardening groups

Community gardens are a great way to learn from experienced gardeners in your area, especially if you're limited on space. Search "community garden Alameda County CA" or check your extension office and local parks department. Facebook groups like "Alameda County Gardeners" or "California Gardening" are also excellent for local advice and plant swaps.

What to Plant After Your Harvest

After your first crops finish, use the remaining frost-free days to grow a second round.

After Sweet Potatoes (harvest ends Jun 14) 181 days until frost
After Watermelon (harvest ends May 24) 202 days until frost
After Green Beans (harvest ends May 10) 216 days until frost
After Potatoes (harvest ends Jun 14) 181 days until frost
Show 6 more succession options
After Squash (Winter) (harvest ends Jun 14) 181 days until frost
After Sweet Corn (harvest ends May 3) 223 days until frost
After Lettuce (harvest ends May 3) 223 days until frost
After Cauliflower (harvest ends May 17) 209 days until frost
After Onion (harvest ends Jun 7) 188 days until frost
After Kale (harvest ends May 10) 216 days until frost

Sunlight & Day Length

Monthly daylight hours and peak sun — critical for onion varieties, photoperiod-sensitive plants, and solar garden planning.

Longest Day

14.6 hours

Summer solstice daylight

Shortest Day

9.4 hours

Winter solstice daylight

Peak Sun Hours

13.2 hr/day peak (summer)

Peak sun hours (green dashed line below) account for cloud cover — this is the usable direct sunlight your garden actually receives. Most vegetables need 6+ peak sun hours.

14hr 12hr 4h 7h 10h 13h 16h Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Daylight hours (sunrise to sunset) Peak sun hours (direct sunlight after cloud cover) ▪ Gold zone = long day (14+ hr) ▪ Blue zone = short day (<12 hr)

Onion tip: Your long summer days (14+ hours) support long-day onion varieties like Walla Walla, Sweet Spanish, and Ailsa Craig.

View detailed monthly data
MonthDaylight HoursPeak Sun HoursDay Length
January 9.7 hr 5.5 hr Short day
February 10.6 hr 6.5 hr Short day
March 11.7 hr 7.7 hr Short day
April 13 hr 9.5 hr Neutral
May 14 hr 11.3 hr Long day
June 14.6 hr 12.4 hr Long day
July 14.4 hr 13.2 hr Long day
August 13.5 hr 11.8 hr Neutral
September 12.2 hr 10.4 hr Neutral
October 11 hr 7.8 hr Short day
November 9.9 hr 6.2 hr Short day
December 9.4 hr 5.1 hr Short day

Peak sun hours factor in typical cloud cover — use these for solar panel and shade-planning calculations.

Soil Temperature & Composting Calendar

Monthly soil temps tell you when to plant warm-season crops, and when your compost pile is actively working.

Plant Warm Crops When

Soil reaches 60°F+

Soil warm enough from Apr through Nov.

Best Month to Compost

Apr

Microbial activity peaks when soil is warm.

Active Composting

11 months

Nearly year-round composting.

60°F 70°F 30° 50° 70° 90° 110° Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
4" depth 8" depth - - - 60°F (corn, beans) - - - 70°F (tomatoes, peppers)
View detailed monthly data
MonthSoil 4" DeepSoil 8" DeepCompost ActivityTime to Finish
Jan 50°F 58°F 🐢 Slow ~24 weeks
Feb 53°F 58°F ♻️ Active ~14 weeks
Mar 59°F 60°F ♻️ Active ~14 weeks
Apr 67°F 66°F 🔥 Peak ~8 weeks
May 76°F 73°F 🔥 Peak ~8 weeks
Jun 86°F 82°F 🔥 Peak ~8 weeks
Jul 92°F 87°F 🔥 Peak ~8 weeks
Aug 95°F 90°F 🔥 Peak ~8 weeks
Sep 90°F 87°F 🔥 Peak ~8 weeks
Oct 78°F 80°F 🔥 Peak ~8 weeks
Nov 67°F 71°F 🔥 Peak ~8 weeks
Dec 58°F 64°F ♻️ Active ~14 weeks

Highlighted rows = soil 60°F+ (safe for warm-season transplants). Compost finishes fastest during peak activity months.

Pest & Disease Pressure in Alameda County

Computed from local climate patterns — warmer, humid conditions increase pest generations and fungal disease risk.

Insect Pest Pressure

8 / 10

High — expect multiple pest generations. Preventative measures essential.

Disease Risk

3.2 / 10

Low disease risk — dry conditions reduce fungal problems.

Seasonal Risk

Spring High
Summer High
Fall High
Winter Low
View 6 common pests in your area
PestRisk LevelPeak Months
Aphids High Feb, Mar, Apr, May, Jun, Jul, Aug, Sep, Oct, Nov
Whiteflies High Apr, May, Jun, Jul, Aug, Sep, Oct, Nov
Spider mites High May, Jun, Jul, Aug, Sep, Oct
Fire ants Moderate Mar, Apr, May, Jun, Jul, Aug, Sep, Oct, Nov
Thrips Moderate Apr, May, Jun, Jul, Aug
Leaf miners Low Mar, Apr, May, Jun
Organic pest management tips
  • Use row covers on susceptible crops during peak pest months
  • Apply neem oil preventatively every 7-14 days during active pest season
  • Interplant with strong-scented herbs (basil, marigold) to confuse pests
  • Hand-pick larger pests (beetles, caterpillars) in early morning when they're sluggish
  • Practice crop rotation — never plant the same family in the same spot within 3 years

Cover Crops for Alameda County

Cover crops protect bare soil, fix nitrogen, suppress weeds, and improve soil structure — with county-specific planting dates.

Spring Cover Crops (4 options) — Build soil before the main growing season
Crop Plant By Terminate N-Fixing Soil Benefit
Buckwheat Jan 24 Oct 3 Rapid growth, attracts pollinators, suppresses weeds
Cowpeas (southern peas) Jan 22 Oct 3 ✓ Yes Excellent nitrogen fixer for warm climates, edible
Sorghum-sudan grass Jan 23 Oct 10 Massive biomass, breaks compaction, suppresses nematodes
White clover Dec 18 Oct 3 ✓ Yes Living mulch, fixes nitrogen, permanent ground cover
Summer Cover Crops (1 options) — Fill gaps and suppress weeds between plantings
Crop Plant By Terminate N-Fixing Soil Benefit
Sunflowers Feb 12 Nov 21 Deep roots break compaction, attract pollinators and beneficial insects
Fall Cover Crops (4 options) — Plant after harvest to protect soil over winter
Crop Plant By Terminate N-Fixing Soil Benefit
Austrian winter peas Oct 10 Jan 4 ✓ Yes Fixes nitrogen, good for heavy clay soils
Crimson clover Oct 16 Dec 28 ✓ Yes Fixes nitrogen, attracts pollinators in spring
Daikon radish Oct 21 Jan 4 Deep taproot breaks compaction, excellent for clay soils
Hairy vetch Sep 20 Jan 4 ✓ Yes Excellent nitrogen fixer, good for depleted soils

Wind & Microclimate

Wind dries soil, stresses plants, and affects frost patterns. Understanding your exposure helps with garden placement.

Seasonal Wind Speed

Spring: 9 mph   Summer: 11 mph

Fall: 9 mph   Winter: 9 mph

Prevailing wind: W. Moderate wind — consider a temporary windbreak for young seedlings.

Windbreak Benefit

5.1/10

Moderately beneficial — a simple fence or trellis can protect delicate crops from wind stress.

Frost Pocket Risk

Low

Relatively flat terrain (379 ft range). Frost pocket risk is minimal — garden placement is flexible.

Rainwater Harvesting Potential

How much water you can collect, when to collect it, and what size system you need for your garden.

Annual Collection

8,123 gal

Per 1,000 sq ft of roof area (at 80% collection efficiency)

Recommended Setup

8 rain barrels (55 gal each)

For a typical 500 sq ft garden. Serious collectors: consider a 2,500 gal tank.

Legal Status

Unrestricted

Rainwater harvesting is fully legal in your state with no restrictions.

Best Collection Months

Jan, Feb, Mar, Dec

Highest rainfall months — your barrels will fill up quickly during these months.

Months to Draw From Storage

May, Jun, Jul, Aug, Sep, Oct

Dry months when you'll rely on stored water — size your storage for this gap.

Rainwater collection tips for your area
  • Your county receives approximately 16.3 inches of rain per year
  • A 1,000 sq ft roof can collect roughly 8,123 gallons annually
  • Rainwater harvesting is fully legal in your state
  • In your dry climate, every drop counts — consider a larger cistern system
  • Position collection tanks in shade to reduce evaporation and algae growth

Soil & Growing Conditions in Alameda County

Soil Type

Loam

Soil pH 6.3–7.7 · Well Drained drainage

Native soil is well-suited to most vegetables and herbs with regular compost additions.

Watering Needs

Drought stress: 7.5/10

High drought stress. Consistent irrigation is essential — consider drip systems, heavy mulch, and drought-tolerant varieties.

Season Tips

329-day frost-free season

Your long season supports multiple successions and heat-demanding crops like melons, sweet potatoes, and peppers. Plant warm-season crops as soon as soil warms.

Free Garden Planner

Plan your entire garden season — organize planting dates, track what you're growing, and know exactly when to start seeds, transplant, and harvest.

Get My Free Planner →

Recommended for Your Garden

☀️
Garden Shade Cloth $15-35

Reduce heat stress and sun scorch in hot climates with UV-stabilized shade cloth.

🧪
Soil Test Kit $12-25

Test your soil pH, nitrogen, phosphorus, and potassium levels before planting.

📏
Digital pH Meter $10-20

Get instant, accurate soil pH readings to fine-tune your amendments.

🥬 Vegetables to Grow in Alameda County

115 vegetables that grow well in Zone 9b with planting dates for Alameda County.

Show all 115 vegetables with planting dates
Plant Start Indoors Direct Sow Transplant Harvest Days to Maturity
Acorn Squash Dec 21 Jan 18 Jan 25 Apr 19 – May 24 80–100
Amaranth Dec 7 Jan 18 Jan 25 Apr 26 – Jun 14 90–120
Artichoke Feb 1 Jun 7 – Aug 16 120–180
Arugula Dec 21 Dec 28 Jan 18 Feb 22 – Apr 26 30–50
Asparagus Feb 1 730–1095
Beets Dec 28 Feb 22 – Mar 22 50–70
Belgian Endive Dec 21 Dec 28 Jan 18 May 10 – Jul 5 110–150
Bitter Melon Dec 7 Jan 18 Jan 25 Mar 29 – May 10 60–90
Black Beans Jan 25 Apr 26 – Jun 14 90–120
Bok Choy Dec 21 Dec 28 Jan 18 Mar 1 – Apr 5 40–60
Broccoli Dec 21 Dec 28 Jan 18 Mar 22 – May 3 60–90
Broccoli Rabe Dec 21 Dec 28 Jan 18 Mar 1 – Apr 5 40–60
Brussels Sprouts Dec 21 Dec 28 Jan 18 Apr 19 – Jun 14 90–130
Butternut Squash Dec 21 Jan 18 Jan 25 Apr 26 – May 31 85–110
Cabbage Dec 21 Dec 28 Jan 18 Mar 22 – May 17 60–100
Calabash Dec 7 Jan 18 Jan 25 Apr 19 – Jun 14 80–120
Cardoon Feb 1 Jun 7 – Jul 19 120–150
Carrots Dec 28 Mar 1 – Apr 5 60–80
Cauliflower Dec 21 Dec 28 Jan 18 Mar 15 – May 17 55–100
Celeriac Dec 21 Dec 28 Jan 18 May 3 – Jun 7 100–120
Celery Dec 21 Dec 28 Jan 18 Apr 12 – Jun 7 80–120
Celtuce Dec 21 Dec 28 Jan 18 Mar 22 – May 3 60–90
Chard Dec 21 Dec 28 Jan 18 Mar 15 – May 3 50–60
Chayote Dec 7 Jan 18 Jan 25 May 31 – Aug 9 120–180
Chickpeas Dec 21 Dec 28 Jan 18 Apr 12 – May 24 80–110
Chicory Dec 21 Dec 28 Jan 18 Mar 22 – May 3 60–85
Chinese Cabbage Dec 21 Dec 28 Jan 18 Mar 15 – Apr 12 50–70
Christmas Lima Beans Dec 7 Jan 18 Jan 25 Apr 19 – May 24 80–100
Collard Greens Dec 21 Dec 28 Jan 18 Mar 15 – May 17 55–75
Corn Jan 25 Mar 29 – May 24 60–100
Cowpeas Jan 25 Mar 29 – May 10 60–90
Cress Dec 21 Dec 28 Jan 18 Feb 1 – Feb 22 14–21
Crookneck Squash Dec 21 Jan 18 Jan 25 Mar 15 – Apr 12 45–60
Crosne Dec 28 May 31 – Aug 2 150–200
Cucumber Dec 21 Jan 18 Jan 25 Mar 22 – May 17 50–70
Daikon Dec 28 Feb 22 – Mar 22 50–70
Delicata Squash Dec 21 Jan 18 Jan 25 Apr 19 – May 24 80–100
Edamame Jan 25 Apr 12 – May 24 75–100
Eggplant Dec 7 Jan 18 Jan 25 Apr 5 – Jun 7 65–85
Endive Dec 21 Dec 28 Jan 18 Mar 8 – Apr 12 45–65
Escarole Dec 21 Dec 28 Jan 18 Mar 15 – Apr 12 50–70
Fava Beans Dec 21 Dec 28 Jan 18 Apr 5 – May 17 75–100
Fennel Dec 7 Jan 18 Jan 25 Mar 29 – May 10 60–90
Garlic 90–240
Ginger Dec 7 Jan 18 Jan 25 Sep 27 – Nov 22 240–300
Green Beans Jan 25 Mar 22 – May 17 50–65
Horseradish Feb 1 Jun 7 – Aug 16 120–180
Hot Peppers Dec 7 Jan 18 Jan 25 Apr 5 – Jul 12 70–120
Hubbard Squash Dec 21 Jan 18 Jan 25 May 10 – Jun 14 100–120
Jicama Dec 7 Jan 18 Jan 25 May 31 – Aug 9 120–180
Kabocha Dec 21 Jan 18 Jan 25 Apr 26 – May 24 85–100
Kai Lan Dec 21 Dec 28 Jan 18 Mar 8 – Apr 5 45–60
Kale Dec 21 Dec 28 Jan 18 Mar 15 – May 10 50–70
Kidney Beans Jan 25 Apr 26 – May 31 85–110
Kohlrabi Dec 21 Dec 28 Jan 18 Mar 8 – Apr 12 45–65
Komatsuna Dec 21 Dec 28 Jan 18 Feb 22 – Mar 29 35–50
Leeks Dec 21 Dec 28 Jan 18 Apr 19 – Jul 5 90–150
Lentils Dec 21 Dec 28 Jan 18 Apr 12 – May 24 80–110
Lettuce Dec 21 Dec 28 Jan 18 Feb 22 – May 3 30–60
Lima Beans Jan 25 Mar 29 – May 10 60–90
Loofah Dec 7 Jan 18 Jan 25 May 10 – Jul 12 100–150
Luffa Dec 7 Jan 18 Jan 25 Apr 26 – Jul 12 90–150
Mache Dec 21 Dec 28 Jan 18 Mar 1 – Apr 5 40–60
Malabar Spinach Dec 7 Jan 18 Jan 25 Mar 22 – Apr 19 55–70
Melon Dec 21 Jan 18 Jan 25 Apr 5 – May 24 70–100
Microgreens Dec 21 Dec 28 Jan 18 Jan 25 – Feb 22 7–21
Mitsuba Dec 21 Dec 28 Jan 11 Mar 8 – May 3 50–70
Mizuna Dec 21 Dec 28 Jan 18 Feb 22 – Mar 22 30–45
Mustard Greens Dec 21 Dec 28 Jan 18 Feb 22 – Apr 26 30–50
Napa Cabbage Dec 21 Dec 28 Jan 18 Mar 15 – Apr 19 55–75
New Zealand Spinach Dec 7 Jan 18 Jan 25 Mar 22 – Apr 19 55–70
Okra Dec 7 Jan 18 Jan 25 Mar 22 – May 17 50–65
Onion Dec 21 Dec 28 Jan 18 Apr 19 – Jun 7 90–120
Pac Choi Dec 21 Dec 28 Jan 18 Mar 1 – Mar 29 40–55
Parsnip Dec 28 Apr 12 – May 24 100–130
Patty Pan Squash Dec 21 Jan 18 Jan 25 Mar 15 – Apr 12 45–60
Peas Dec 21 Dec 28 Jan 18 Mar 15 – May 10 55–70
Peppers Dec 7 Jan 18 Jan 25 Mar 29 – Jun 7 60–90
Pole Beans Dec 7 Jan 18 Jan 25 Mar 22 – May 17 55–70
Potatoes Dec 7 Jan 18 Jan 25 Apr 5 – Jun 14 70–120
Pumpkin Dec 21 Jan 18 Jan 25 Apr 26 – Jun 14 85–120
Purslane Dec 21 Dec 28 Jan 18 Mar 1 – Apr 5 40–60
Radicchio Dec 21 Dec 28 Jan 18 Mar 22 – Apr 26 60–80
Radish Dec 28 Jan 25 – Feb 15 22–35
Romanesco Dec 21 Dec 28 Jan 18 Apr 5 – May 17 75–100
Rutabaga Dec 28 Mar 22 – Apr 26 80–100
Salsify Dec 28 Apr 12 – May 24 100–130
Savoy Cabbage Dec 21 Dec 28 Jan 18 Mar 29 – May 24 70–110
Scallions Dec 21 Dec 28 Jan 18 Mar 15 – Apr 12 50–70
Scarlet Runner Beans Dec 7 Jan 18 Jan 25 Mar 29 – May 3 60–80
Shallot Dec 21 Dec 28 Jan 18 Apr 19 – Jun 7 90–120
Shiso Dec 7 Jan 25 Jan 25 Mar 22 – May 17 50–70
Snap Peas Dec 7 Jan 18 Jan 25 Mar 22 – May 17 55–70
Snow Peas Dec 21 Dec 28 Jan 18 Mar 15 – May 10 50–65
Soybeans Jan 25 Apr 19 – Jun 14 80–120
Spaghetti Squash Dec 21 Jan 18 Jan 25 Apr 26 – May 24 85–100
Spinach Dec 21 Dec 28 Jan 18 Feb 22 – Apr 26 35–50
Squash (Summer) Dec 21 Jan 18 Jan 25 Mar 15 – May 17 45–65
Squash (Winter) Dec 21 Jan 18 Jan 25 Apr 19 – Jun 14 80–120
Sunchoke Feb 1 May 24 – Jul 19 110–150
Sunflower Dec 7 Jan 18 Jan 25 Apr 5 – May 24 70–100
Sweet Corn Jan 25 Mar 29 – May 10 60–90
Sweet Potatoes Dec 7 Jan 18 Jan 25 Apr 26 – Jun 14 90–120
Tatsoi Dec 21 Dec 28 Jan 18 Feb 22 – Mar 29 35–50
Tomatillo Dec 7 Jan 18 Jan 25 Mar 29 – Jun 7 60–85
Tomatoes Dec 7 Jan 18 Jan 25 Mar 29 – Jun 7 60–85
Turmeric Dec 7 Jan 18 Jan 25 Sep 27 – Nov 22 240–300
Turnip Dec 28 Feb 8 – Mar 15 40–60
Watercress Dec 21 Dec 28 Jan 18 Mar 1 – Apr 5 40–60
Watermelon Dec 21 Jan 18 Jan 25 Apr 5 – May 24 70–100
Wax Beans Jan 25 Mar 22 – May 17 50–65
Winter Melon Dec 7 Jan 18 Jan 25 Apr 26 – Jun 14 90–120
Yam Dec 7 Jan 18 Jan 25 Jul 26 – Nov 22 180–330
Yard Long Beans Dec 7 Jan 18 Jan 25 Mar 22 – May 3 55–80
Zucchini Dec 21 Jan 18 Jan 25 Mar 15 – May 10 45–60

🍓 Fruits to Grow in Alameda County

24 fruits that grow well in Zone 9b with planting dates for Alameda County.

Show all 24 fruits with planting dates
Plant Start Indoors Direct Sow Transplant Harvest Days to Maturity
Alpine Strawberries Feb 1 May 3 – Aug 16 90–180
Blackberries Feb 1 365–730
Boysenberries Feb 1 365–730
Cantaloupe Feb 1 Apr 12 – May 17 70–90
Che Fruit Feb 1 1095–1825
Dragon Fruit Feb 1 365–730
Elderberries Feb 1 730–1095
Figs Feb 1 730–1825
Goji Berries Feb 1 730–1095
Grapes Feb 1 730–1095
Ground Cherry Feb 1 Apr 12 – Jun 7 65–80
Guava Feb 1 365–730
Honeydew Feb 1 Apr 26 – Jun 7 80–110
Kiwi Feb 1 1095–1825
Loquat Feb 1 730–1825
Mulberries Feb 1 730–1825
Passion Fruit Feb 1 365–545
Pawpaw Feb 1 1095–2555
Persimmon Feb 1 1095–2555
Pomegranate Feb 1 730–1095
Quince Feb 1 1095–1825
Raspberries Feb 1 365–730
Serviceberries Feb 1 730–1095
Strawberries Feb 1 May 3 – Nov 29 90–365

🌿 Herbs to Grow in Alameda County

40 herbs that grow well in Zone 9b with planting dates for Alameda County.

Show all 40 herbs with planting dates
Plant Start Indoors Direct Sow Transplant Harvest Days to Maturity
Anise Dec 21 Dec 28 Jan 11 Apr 12 – Jun 28 90–120
Basil Dec 7 Jan 25 Jan 25 Mar 22 – May 24 50–75
Bee Balm Jan 25 Apr 26 – Jul 12 90–120
Borage Dec 21 Dec 28 Jan 11 Mar 8 – Apr 26 50–60
Caraway Dec 21 Dec 28 Jan 11 365–450
Catnip Jan 25 Mar 29 – May 31 60–80
Chamomile Dec 21 Dec 28 Jan 11 Mar 15 – May 24 60–90
Chervil Dec 21 Dec 28 Jan 11 Feb 22 – Apr 26 40–60
Chives Jan 25 Mar 29 – Jun 7 60–90
Cilantro Dec 21 Dec 28 Jan 11 Feb 22 – Apr 26 40–60
Comfrey Jan 25 Mar 29 – Jun 7 60–90
Cumin Dec 21 Dec 28 Jan 11 Apr 26 – Jun 28 100–120
Dill Dec 21 Dec 28 Jan 11 Feb 22 – Apr 26 40–60
Echinacea Jan 25 May 31 – Sep 6 120–180
Epazote Dec 7 Jan 25 Jan 25 Mar 15 – May 10 45–60
Fennel (herb) Dec 21 Dec 28 Jan 11 Mar 15 – May 24 60–90
Feverfew Jan 25 Apr 26 – Jul 12 90–120
Garlic Chives Jan 25 Mar 29 – Jun 7 60–90
Horehound Jan 25 Apr 12 – Jun 7 75–90
Hyssop Jan 25 Apr 5 – Jun 7 70–90
Lavender Jan 25 Apr 26 – Sep 27 90–200
Lemon Balm Jan 25 Mar 29 – May 17 60–70
Lemon Thyme Jan 25 Apr 5 – Jun 7 70–90
Lemon Verbena Dec 7 Jan 25 Jan 25 Mar 29 – Jun 7 60–90
Lemongrass Dec 7 Jan 25 Jan 25 Apr 12 – Jul 12 75–120
Marjoram Jan 25 Mar 29 – Jun 7 60–90
Mint Jan 25 Mar 29 – Jun 7 60–90
Oregano Jan 25 Mar 29 – Jun 7 60–90
Parsley Dec 21 Dec 28 Jan 11 Mar 15 – May 17 60–80
Rosemary Jan 25 Apr 19 – Sep 6 80–180
Rue Jan 25 Apr 5 – Jun 7 70–90
Sage Jan 25 Apr 12 – Jun 7 75–90
Savory Jan 25 Mar 22 – May 17 50–70
Sorrel Dec 21 Dec 28 Jan 11 Feb 22 – Apr 26 40–60
Stevia Dec 7 Jan 25 Jan 25 Mar 29 – Jun 7 60–90
Tarragon Jan 25 Mar 29 – Jun 7 60–90
Thai Basil Dec 7 Jan 25 Jan 25 Mar 22 – May 24 50–75
Thyme Jan 25 Apr 5 – Jun 7 70–90
Valerian Jan 25 May 31 – Sep 6 120–180
Yarrow Jan 25 Apr 26 – Jul 12 90–120

Monthly Planting Guide for Alameda County

Gardening Guides & Resources

Helpful guides from The Ultimate Homestead to improve your garden in Alameda County.

Frequently Asked Questions

What planting zone is Alameda County, CA?

Alameda County is in USDA Hardiness Zone 9b. This zone classification determines which perennial plants survive winter and sets the baseline for frost timing across the county.

When is the last frost in Alameda County, CA?

Based on 13 years of NOAA weather station data, the median last spring frost in Alameda County falls around January 18. In 8 out of 10 years, last frost lands between January 5 and March 24 — a 79-day window of variability. Use March 24 as your conservative safe-to-plant date for frost-sensitive crops.

When is the first fall frost in Alameda County, CA?

The median first fall frost in Alameda County arrives around December 12. In cold years it can arrive as early as November 22; in mild years as late as December 24. Harvest or protect frost-sensitive crops — tomatoes, peppers, basil, squash — before this date.

How long is the growing season in Alameda County?

Alameda County has a frost-free growing season of approximately 329 days. This long season supports multiple succession plantings and warm-season crops that need extended heat, like sweet potatoes and melons. Climate records show the growing season is trending longer by about 25.71 days per decade.

What is the soil like in Alameda County for gardening?

Alameda County has predominantly Loam soil with a pH range of 6.3–7.7 and Well Drained drainage. Most vegetables and herbs grow well with standard composting and seasonal soil amendment.

What is grown commercially in Alameda County?

Alameda County has commercial agriculture that includes Almonds, Grapes, Dairy, Tomatoes, Walnuts. These crops reflect the local climate and soil conditions — what succeeds commercially often translates well to home gardens in the same area.

Is Alameda County a good location for home gardening?

Alameda County scores 43/100 (Moderate) on our Microclimate Index, which combines frost reliability, drought pressure, soil challenge, elevation risk, and long-term climate trend. Gardening here benefits from close attention to frost timing and season extension due to the challenging microclimate factors.

🌱

Plan Your Garden with Confidence

Get our free Garden Planner — designed to help Alameda County gardeners in Zone 9b organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA GHCN-D daily station data (1994–2024) from 3 weather stations in or near Alameda County (13 years of records). Frost dates represent 50% probability averages; local conditions vary by elevation and microclimate. Last updated: April 2026.