San Diego County, CA — Planting Guide
May in San Diego County, California — your action list
We've pulled the most time-sensitive tasks for San Diego County, California this May and put them front and centre. Tackle them in order.
-
Fire up the seed-starting tray: basil, cucumber, and kale
Starting these indoors now means sturdy transplants ready the moment your soil warms up.
-
Collect carrots, lettuce, and radish at their peak
This is the payoff month. Bring a basket, bring a friend, and get into the beds.
Coming up in June — start thinking about
- First harvests: basil, carrots, and cucumber
San Diego County is in USDA Zone 10b. The average last spring frost is April 16 and the first fall frost is November 1, giving you a growing season of approximately 199 days.
At an elevation of 2,613 ft, San Diego County receives approximately 18.2 in of rainfall annually. Summer highs average 92°F with winter lows around 51°F. The predominant soil type is Loam.
Based on 31 years of NOAA climate station data, the last frost date here varies by 73 days year to year — ranging from March 9 in warm years to May 21 in cold years. The growing season is trending shorter by about 4.57 days per decade. San Diego County scores 39/100 (Challenging) on the Microclimate Index.
🌡️ Zone
10b (°F to °F min)
❄️ Last Frost
April 16
🍂 First Frost
November 1
📅 Growing Season
199 days
⛰️ Elevation
2,613 ft
🌧️ Annual Rainfall
18.2 in
Monthly Watering Calendar
When you'll need to water your garden — based on average monthly rainfall vs. the ~1 inch/week most gardens need.
View detailed monthly data
| Month | Avg Rainfall | Rainy Days | Extra Water Needed | Watering Effort |
|---|---|---|---|---|
| Jan | 3 in | 9 days | 1.3 in | Moderate |
| Feb | 3.9 in | 10 days | 0.4 in | Low |
| Mar | 3.1 in | 8 days | 1.2 in | Moderate |
| Apr | 1.4 in | 5 days | 2.9 in | High |
| May | 0.5 in | 1 days | 3.8 in | Critical |
| Jun | 0.1 in | 1 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 | 0.8 in | 2 days | 3.5 in | Critical |
| Nov | 1.8 in | 6 days | 2.5 in | High |
| Dec | 3.3 in | 8 days | 1 in | Moderate |
Annual total: 18.1 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.
San Diego County Soil Profile
Soil Type
Loam
Soil pH
5.7-7.5
Drainage
Well Drained
Frost Risk Probability
Based on 31 years of NOAA weather station data from 3 stations
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) | May 21 | Dec 2 | 195 days |
| Cautious | Apr 26 | Nov 18 | 206 days |
| Average year | Apr 16 | Nov 1 | 199 days |
| Optimistic | Apr 9 | Oct 20 | 194 days |
| Aggressive (risky) | Mar 9 | Oct 6 | 211 days |
Not very — frost dates can vary by ±73 days year-to-year. Use the "Conservative" row in the table below, and keep row covers handy for surprise late frosts.
Yes — growing seasons are getting shorter here (about 4.6 days per decade). Use the "Conservative" dates and choose fast-maturing varieties.
Gardening Difficulty Score
San Diego County has challenging growing conditions. Season extension and careful variety selection are essential.
Local Gardening Help in San Diego 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 San Diego County's climate and soil.
County Extension Office
San Diego 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.
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.
Services Available in San Diego County
Finding local nurseries & garden centers in San Diego County
Why Buy Local
Local nurseries carry plants that are proven to grow in your area. Staff can give you advice specific to San Diego 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 San Diego County CA" or "garden center San Diego 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 San Diego County CA" or check your extension office and local parks department. Facebook groups like "San Diego 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.
Show 6 more succession options
Sunlight & Day Length
Monthly daylight hours and peak sun — critical for onion varieties, photoperiod-sensitive plants, and solar garden planning.
Longest Day
14.2 hours
Summer solstice daylight
Shortest Day
9.8 hours
Winter solstice daylight
Peak Sun Hours
13.1 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.
Onion tip: Day-neutral onion varieties like Candy, Cabernet, and Sierra Blanca perform best in your day-length range.
View detailed monthly data
| Month | Daylight Hours | Peak Sun Hours | Day Length |
|---|---|---|---|
| January | 10 hr | 5.6 hr | Short day |
| February | 10.8 hr | 6.4 hr | Short day |
| March | 11.8 hr | 7.8 hr | Short day |
| April | 12.8 hr | 9.5 hr | Neutral |
| May | 13.7 hr | 11.4 hr | Neutral |
| June | 14.2 hr | 12.9 hr | Long day |
| July | 14 hr | 13.1 hr | Long day |
| August | 13.2 hr | 11.9 hr | Neutral |
| September | 12.2 hr | 10.6 hr | Neutral |
| October | 11.2 hr | 8.4 hr | Short day |
| November | 10.3 hr | 6.1 hr | Short day |
| December | 9.8 hr | 5.4 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 Mar through Nov.
Best Month to Compost
Apr
Microbial activity peaks when soil is warm.
Active Composting
12 months
Nearly year-round composting.
View detailed monthly data
| Month | Soil 4" Deep | Soil 8" Deep | Compost Activity | Time to Finish |
|---|---|---|---|---|
| Jan | 51°F | 58°F | ♻️ Active | ~14 weeks |
| Feb | 55°F | 59°F | ♻️ Active | ~14 weeks |
| Mar | 60°F | 62°F | ♻️ Active | ~14 weeks |
| Apr | 66°F | 66°F | 🔥 Peak | ~8 weeks |
| May | 75°F | 72°F | 🔥 Peak | ~8 weeks |
| Jun | 80°F | 79°F | 🔥 Peak | ~8 weeks |
| Jul | 89°F | 84°F | 🔥 Peak | ~8 weeks |
| Aug | 88°F | 86°F | 🔥 Peak | ~8 weeks |
| Sep | 87°F | 84°F | 🔥 Peak | ~8 weeks |
| Oct | 79°F | 78°F | 🔥 Peak | ~8 weeks |
| Nov | 67°F | 71°F | 🔥 Peak | ~8 weeks |
| Dec | 58°F | 62°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 San Diego County
Computed from local climate patterns — warmer, humid conditions increase pest generations and fungal disease risk.
Insect Pest Pressure
Moderate — common pests appear but manageable with monitoring.
Disease Risk
Low disease risk — dry conditions reduce fungal problems.
Seasonal Risk
View 6 common pests in your area
| Pest | Risk Level | Peak Months |
|---|---|---|
| Aphids | High | Jan, Feb, Mar, Apr, May, Jun, Jul, Aug, Sep, Oct, Nov, Dec |
| Whiteflies | High | Jan, Feb, Mar, Apr, May, Jun, Jul, Aug, Sep, Oct, Nov, Dec |
| Spider mites | High | Mar, Apr, May, Jun, Jul, Aug, Sep, Oct, Nov |
| Thrips | High | Mar, Apr, May, Jun, Jul, Aug, Sep |
| Scale insects | Moderate | Apr, May, Jun, Jul, Aug, Sep, Oct |
| Nematodes | Moderate | May, Jun, Jul, Aug, Sep |
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 San Diego 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 | Apr 21 | Sep 6 | — | Rapid growth, attracts pollinators, suppresses weeds |
| Cowpeas (southern peas) | Apr 21 | Aug 23 | ✓ Yes | Excellent nitrogen fixer for warm climates, edible |
| Sorghum-sudan grass | Apr 26 | Aug 30 | — | Massive biomass, breaks compaction, suppresses nematodes |
| White clover | Mar 22 | Sep 6 | ✓ 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 | May 3 | Oct 11 | — | Deep roots break compaction, attract pollinators and beneficial insects |
Fall Cover Crops (1 options) — Plant after harvest to protect soil over winter
| Crop | Plant By | Terminate | N-Fixing | Soil Benefit |
|---|---|---|---|---|
| Crimson clover | Aug 27 | Mar 26 | ✓ Yes | Fixes nitrogen, attracts pollinators in spring |
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: 10 mph
Fall: 9 mph Winter: 9 mph
Prevailing wind: W. Moderate wind — consider a temporary windbreak for young seedlings.
Windbreak Benefit
5.4/10
Moderately beneficial — a simple fence or trellis can protect delicate crops from wind stress.
Frost Pocket Risk
Moderate
Some terrain variation (838 ft range). Garden on slopes or higher ground if possible to avoid late-season frost pockets.
Rainwater Harvesting Potential
How much water you can collect, when to collect it, and what size system you need for your garden.
Annual Collection
9,021 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 18.1 inches of rain per year
- A 1,000 sq ft roof can collect roughly 9,021 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 San Diego County
Soil Type
Loam
Soil pH 5.7–7.5 · Well Drained drainage
Good candidate for raised beds to maximise drainage and extend the season.
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
199-day frost-free season
Plenty of time for warm-season crops. Start heat-lovers indoors 6–8 weeks before last frost to maximise your harvest window.
Your Free Printable Garden Planner
Plan every bed, every planting, every harvest — in one place. This 24-page printable includes your zone's planting calendar, a month-by-month task list, a seed inventory tracker, a harvest log, and succession-planting charts. Built to print, write in, and actually use all season.
Recommended for Your Garden
Reduce heat stress and sun scorch in hot climates with UV-stabilized shade cloth.
Test your soil pH, nitrogen, phosphorus, and potassium levels before planting.
Get instant, accurate soil pH readings to fine-tune your amendments.
🥬 Vegetables to Grow in San Diego County
106 vegetables that grow well in Zone 10b with planting dates for San Diego County.
Show all 106 vegetables with planting dates
| Plant | Start Indoors | Direct Sow | Transplant | Harvest | Days to Maturity |
|---|---|---|---|---|---|
| Acorn Squash | Mar 19 | Apr 16 | Apr 23 | Jul 16 – Aug 20 | 80–100 |
| Amaranth | Mar 5 | Apr 16 | Apr 23 | Jul 23 – Sep 10 | 90–120 |
| Artichoke | — | — | Apr 30 | Sep 3 – Nov 12 | 120–180 |
| Arugula | Mar 19 | Mar 26 | Apr 16 | May 21 – Jul 23 | 30–50 |
| Asparagus | — | — | Apr 30 | — | 730–1095 |
| Beets | — | Mar 26 | — | May 21 – Jun 18 | 50–70 |
| Belgian Endive | Mar 19 | Mar 26 | Apr 16 | Aug 6 – Oct 1 | 110–150 |
| Bitter Melon | Mar 5 | Apr 16 | Apr 23 | Jun 25 – Aug 6 | 60–90 |
| Black Beans | — | Apr 23 | — | Jul 23 – Sep 10 | 90–120 |
| Bok Choy | Mar 19 | Mar 26 | Apr 16 | May 28 – Jul 2 | 40–60 |
| Broccoli | Mar 19 | Mar 26 | Apr 16 | Jun 18 – Jul 30 | 60–90 |
| Broccoli Rabe | Mar 19 | Mar 26 | Apr 16 | May 28 – Jul 2 | 40–60 |
| Brussels Sprouts | Mar 19 | Mar 26 | Apr 16 | Jul 16 – Sep 10 | 90–130 |
| Butternut Squash | Mar 19 | Apr 16 | Apr 23 | Jul 23 – Aug 27 | 85–110 |
| Cabbage | Mar 19 | Mar 26 | Apr 16 | Jun 18 – Aug 13 | 60–100 |
| Calabash | Mar 5 | Apr 16 | Apr 23 | Jul 16 – Sep 10 | 80–120 |
| Cardoon | — | — | Apr 30 | Sep 3 – Oct 15 | 120–150 |
| Carrots | — | Mar 26 | — | May 28 – Jul 2 | 60–80 |
| Cauliflower | Mar 19 | Mar 26 | Apr 16 | Jun 11 – Aug 13 | 55–100 |
| Celery | Mar 19 | Mar 26 | Apr 16 | Jul 9 – Sep 3 | 80–120 |
| Celtuce | Mar 19 | Mar 26 | Apr 16 | Jun 18 – Jul 30 | 60–90 |
| Chard | Mar 19 | Mar 26 | Apr 16 | Jun 11 – Jul 30 | 50–60 |
| Chayote | Mar 5 | Apr 16 | Apr 23 | Aug 27 – Nov 5 | 120–180 |
| Chickpeas | Mar 19 | Mar 26 | Apr 16 | Jul 9 – Aug 20 | 80–110 |
| Chicory | Mar 19 | Mar 26 | Apr 16 | Jun 18 – Jul 30 | 60–85 |
| Chinese Cabbage | Mar 19 | Mar 26 | Apr 16 | Jun 11 – Jul 9 | 50–70 |
| Christmas Lima Beans | Mar 5 | Apr 16 | Apr 23 | Jul 16 – Aug 20 | 80–100 |
| Collard Greens | Mar 19 | Mar 26 | Apr 16 | Jun 11 – Aug 13 | 55–75 |
| Corn | — | Apr 23 | — | Jun 25 – Aug 20 | 60–100 |
| Cowpeas | — | Apr 23 | — | Jun 25 – Aug 6 | 60–90 |
| Cress | Mar 19 | Mar 26 | Apr 16 | Apr 30 – May 21 | 14–21 |
| Crookneck Squash | Mar 19 | Apr 16 | Apr 23 | Jun 11 – Jul 9 | 45–60 |
| Cucumber | Mar 19 | Apr 16 | Apr 23 | Jun 18 – Aug 13 | 50–70 |
| Daikon | — | Mar 26 | — | May 21 – Jun 18 | 50–70 |
| Delicata Squash | Mar 19 | Apr 16 | Apr 23 | Jul 16 – Aug 20 | 80–100 |
| Edamame | — | Apr 23 | — | Jul 9 – Aug 20 | 75–100 |
| Eggplant | Mar 5 | Apr 16 | Apr 23 | Jul 2 – Sep 3 | 65–85 |
| Endive | Mar 19 | Mar 26 | Apr 16 | Jun 4 – Jul 9 | 45–65 |
| Escarole | Mar 19 | Mar 26 | Apr 16 | Jun 11 – Jul 9 | 50–70 |
| Fava Beans | Mar 19 | Mar 26 | Apr 16 | Jul 2 – Aug 13 | 75–100 |
| Fennel | Mar 5 | Apr 16 | Apr 23 | Jun 25 – Aug 6 | 60–90 |
| Ginger | Mar 5 | Apr 16 | Apr 23 | Dec 24 – Mar 4 | 240–300 |
| Green Beans | — | Apr 23 | — | Jun 18 – Aug 13 | 50–65 |
| Hot Peppers | Mar 5 | Apr 16 | Apr 23 | Jul 2 – Oct 8 | 70–120 |
| Hubbard Squash | Mar 19 | Apr 16 | Apr 23 | Aug 6 – Sep 10 | 100–120 |
| Jicama | Mar 5 | Apr 16 | Apr 23 | Aug 27 – Nov 5 | 120–180 |
| Kabocha | Mar 19 | Apr 16 | Apr 23 | Jul 23 – Aug 20 | 85–100 |
| Kai Lan | Mar 19 | Mar 26 | Apr 16 | Jun 4 – Jul 2 | 45–60 |
| Kale | Mar 19 | Mar 26 | Apr 16 | Jun 11 – Aug 6 | 50–70 |
| Kidney Beans | — | Apr 23 | — | Jul 23 – Aug 27 | 85–110 |
| Kohlrabi | Mar 19 | Mar 26 | Apr 16 | Jun 4 – Jul 9 | 45–65 |
| Komatsuna | Mar 19 | Mar 26 | Apr 16 | May 21 – Jun 25 | 35–50 |
| Leeks | Mar 19 | Mar 26 | Apr 16 | Jul 16 – Oct 1 | 90–150 |
| Lentils | Mar 19 | Mar 26 | Apr 16 | Jul 9 – Aug 20 | 80–110 |
| Lettuce | Mar 19 | Mar 26 | Apr 16 | May 21 – Jul 30 | 30–60 |
| Lima Beans | — | Apr 23 | — | Jun 25 – Aug 6 | 60–90 |
| Loofah | Mar 5 | Apr 16 | Apr 23 | Aug 6 – Oct 8 | 100–150 |
| Luffa | Mar 5 | Apr 16 | Apr 23 | Jul 23 – Oct 8 | 90–150 |
| Mache | Mar 19 | Mar 26 | Apr 16 | May 28 – Jul 2 | 40–60 |
| Malabar Spinach | Mar 5 | Apr 16 | Apr 23 | Jun 18 – Jul 16 | 55–70 |
| Melon | Mar 19 | Apr 16 | Apr 23 | Jul 2 – Aug 20 | 70–100 |
| Microgreens | Mar 19 | Mar 26 | Apr 16 | Apr 23 – May 21 | 7–21 |
| Mizuna | Mar 19 | Mar 26 | Apr 16 | May 21 – Jun 18 | 30–45 |
| Mustard Greens | Mar 19 | Mar 26 | Apr 16 | May 21 – Jul 23 | 30–50 |
| Napa Cabbage | Mar 19 | Mar 26 | Apr 16 | Jun 11 – Jul 16 | 55–75 |
| New Zealand Spinach | Mar 5 | Apr 16 | Apr 23 | Jun 18 – Jul 16 | 55–70 |
| Okra | Mar 5 | Apr 16 | Apr 23 | Jun 18 – Aug 13 | 50–65 |
| Onion | Mar 19 | Mar 26 | Apr 16 | Jul 16 – Sep 3 | 90–120 |
| Pac Choi | Mar 19 | Mar 26 | Apr 16 | May 28 – Jun 25 | 40–55 |
| Patty Pan Squash | Mar 19 | Apr 16 | Apr 23 | Jun 11 – Jul 9 | 45–60 |
| Peas | Mar 19 | Mar 26 | Apr 16 | Jun 11 – Aug 6 | 55–70 |
| Peppers | Mar 5 | Apr 16 | Apr 23 | Jun 25 – Sep 3 | 60–90 |
| Pole Beans | Mar 5 | Apr 16 | Apr 23 | Jun 18 – Aug 13 | 55–70 |
| Potatoes | Mar 5 | Apr 16 | Apr 23 | Jul 2 – Sep 10 | 70–120 |
| Pumpkin | Mar 19 | Apr 16 | Apr 23 | Jul 23 – Sep 10 | 85–120 |
| Purslane | Mar 19 | Mar 26 | Apr 16 | May 28 – Jul 2 | 40–60 |
| Radicchio | Mar 19 | Mar 26 | Apr 16 | Jun 18 – Jul 23 | 60–80 |
| Radish | — | Mar 26 | — | Apr 23 – May 14 | 22–35 |
| Romanesco | Mar 19 | Mar 26 | Apr 16 | Jul 2 – Aug 13 | 75–100 |
| Savoy Cabbage | Mar 19 | Mar 26 | Apr 16 | Jun 25 – Aug 20 | 70–110 |
| Scallions | Mar 19 | Mar 26 | Apr 16 | Jun 11 – Jul 9 | 50–70 |
| Scarlet Runner Beans | Mar 5 | Apr 16 | Apr 23 | Jun 25 – Jul 30 | 60–80 |
| Shallot | Mar 19 | Mar 26 | Apr 16 | Jul 16 – Sep 3 | 90–120 |
| Shiso | Mar 5 | Apr 23 | Apr 23 | Jun 18 – Aug 13 | 50–70 |
| Snap Peas | Mar 5 | Apr 16 | Apr 23 | Jun 18 – Aug 13 | 55–70 |
| Snow Peas | Mar 19 | Mar 26 | Apr 16 | Jun 11 – Aug 6 | 50–65 |
| Soybeans | — | Apr 23 | — | Jul 16 – Sep 10 | 80–120 |
| Spaghetti Squash | Mar 19 | Apr 16 | Apr 23 | Jul 23 – Aug 20 | 85–100 |
| Spinach | Mar 19 | Mar 26 | Apr 16 | May 21 – Jul 23 | 35–50 |
| Squash (Summer) | Mar 19 | Apr 16 | Apr 23 | Jun 11 – Aug 13 | 45–65 |
| Squash (Winter) | Mar 19 | Apr 16 | Apr 23 | Jul 16 – Sep 10 | 80–120 |
| Sunflower | Mar 5 | Apr 16 | Apr 23 | Jul 2 – Aug 20 | 70–100 |
| Sweet Corn | — | Apr 23 | — | Jun 25 – Aug 6 | 60–90 |
| Sweet Potatoes | Mar 5 | Apr 16 | Apr 23 | Jul 23 – Sep 10 | 90–120 |
| Tatsoi | Mar 19 | Mar 26 | Apr 16 | May 21 – Jun 25 | 35–50 |
| Tomatillo | Mar 5 | Apr 16 | Apr 23 | Jun 25 – Sep 3 | 60–85 |
| Tomatoes | Mar 5 | Apr 16 | Apr 23 | Jun 25 – Sep 3 | 60–85 |
| Turmeric | Mar 5 | Apr 16 | Apr 23 | Dec 24 – Mar 4 | 240–300 |
| Turnip | — | Mar 26 | — | May 7 – Jun 11 | 40–60 |
| Watercress | Mar 19 | Mar 26 | Apr 16 | May 28 – Jul 2 | 40–60 |
| Watermelon | Mar 19 | Apr 16 | Apr 23 | Jul 2 – Aug 20 | 70–100 |
| Wax Beans | — | Apr 23 | — | Jun 18 – Aug 13 | 50–65 |
| Winter Melon | Mar 5 | Apr 16 | Apr 23 | Jul 23 – Sep 10 | 90–120 |
| Yam | Mar 5 | Apr 16 | Apr 23 | Oct 22 – Apr 8 | 180–330 |
| Yard Long Beans | Mar 5 | Apr 16 | Apr 23 | Jun 18 – Jul 30 | 55–80 |
| Zucchini | Mar 19 | Apr 16 | Apr 23 | Jun 11 – Aug 6 | 45–60 |
🍓 Fruits to Grow in San Diego County
16 fruits that grow well in Zone 10b with planting dates for San Diego County.
Show all 16 fruits with planting dates
| Plant | Start Indoors | Direct Sow | Transplant | Harvest | Days to Maturity |
|---|---|---|---|---|---|
| Alpine Strawberries | — | — | Apr 30 | Jul 30 – Nov 12 | 90–180 |
| Blackberries | — | — | Apr 30 | — | 365–730 |
| Boysenberries | — | — | Apr 30 | — | 365–730 |
| Cantaloupe | — | — | Apr 30 | Jul 9 – Aug 13 | 70–90 |
| Che Fruit | — | — | Apr 30 | — | 1095–1825 |
| Dragon Fruit | — | — | Apr 30 | — | 365–730 |
| Figs | — | — | Apr 30 | — | 730–1825 |
| Goji Berries | — | — | Apr 30 | — | 730–1095 |
| Grapes | — | — | Apr 30 | — | 730–1095 |
| Ground Cherry | — | — | Apr 30 | Jul 9 – Sep 3 | 65–80 |
| Guava | — | — | Apr 30 | — | 365–730 |
| Honeydew | — | — | Apr 30 | Jul 23 – Sep 3 | 80–110 |
| Loquat | — | — | Apr 30 | — | 730–1825 |
| Passion Fruit | — | — | Apr 30 | — | 365–545 |
| Pomegranate | — | — | Apr 30 | — | 730–1095 |
| Strawberries | — | — | Apr 30 | Jul 30 – Apr 29 | 90–365 |
🌿 Herbs to Grow in San Diego County
23 herbs that grow well in Zone 10b with planting dates for San Diego County.
Show all 23 herbs with planting dates
| Plant | Start Indoors | Direct Sow | Transplant | Harvest | Days to Maturity |
|---|---|---|---|---|---|
| Anise | Mar 19 | Mar 26 | Apr 9 | Jul 9 – Sep 24 | 90–120 |
| Basil | Mar 5 | Apr 23 | Apr 23 | Jun 18 – Aug 20 | 50–75 |
| Borage | Mar 19 | Mar 26 | Apr 9 | Jun 4 – Jul 23 | 50–60 |
| Chervil | Mar 19 | Mar 26 | Apr 9 | May 21 – Jul 23 | 40–60 |
| Chives | — | — | Apr 23 | Jun 25 – Sep 3 | 60–90 |
| Cilantro | Mar 19 | Mar 26 | Apr 9 | May 21 – Jul 23 | 40–60 |
| Cumin | Mar 19 | Mar 26 | Apr 9 | Jul 23 – Sep 24 | 100–120 |
| Dill | Mar 19 | Mar 26 | Apr 9 | May 21 – Jul 23 | 40–60 |
| Epazote | Mar 5 | Apr 23 | Apr 23 | Jun 11 – Aug 6 | 45–60 |
| Fennel (herb) | Mar 19 | Mar 26 | Apr 9 | Jun 11 – Aug 20 | 60–90 |
| Garlic Chives | — | — | Apr 23 | Jun 25 – Sep 3 | 60–90 |
| Horehound | — | — | Apr 23 | Jul 9 – Sep 3 | 75–90 |
| Lemon Verbena | Mar 5 | Apr 23 | Apr 23 | Jun 25 – Sep 3 | 60–90 |
| Lemongrass | Mar 5 | Apr 23 | Apr 23 | Jul 9 – Oct 8 | 75–120 |
| Marjoram | — | — | Apr 23 | Jun 25 – Sep 3 | 60–90 |
| Mint | — | — | Apr 23 | Jun 25 – Sep 3 | 60–90 |
| Oregano | — | — | Apr 23 | Jun 25 – Sep 3 | 60–90 |
| Parsley | Mar 19 | Mar 26 | Apr 9 | Jun 11 – Aug 13 | 60–80 |
| Rosemary | — | — | Apr 23 | Jul 16 – Dec 3 | 80–180 |
| Sage | — | — | Apr 23 | Jul 9 – Sep 3 | 75–90 |
| Savory | — | — | Apr 23 | Jun 18 – Aug 13 | 50–70 |
| Stevia | Mar 5 | Apr 23 | Apr 23 | Jun 25 – Sep 3 | 60–90 |
| Thai Basil | Mar 5 | Apr 23 | Apr 23 | Jun 18 – Aug 20 | 50–75 |
Monthly Planting Guide for San Diego County
Gardening Guides & Resources
Helpful guides from The Ultimate Homestead to improve your garden in San Diego County.
Frequently Asked Questions
What planting zone is San Diego County, CA?
San Diego County is in USDA Hardiness Zone 10b. 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 San Diego County, CA?
Based on 31 years of NOAA weather station data, the median last spring frost in San Diego County falls around April 16. In 8 out of 10 years, last frost lands between March 9 and May 21 — a 73-day window of variability. Use May 21 as your conservative safe-to-plant date for frost-sensitive crops.
When is the first fall frost in San Diego County, CA?
The median first fall frost in San Diego County arrives around November 1. In cold years it can arrive as early as October 6; in mild years as late as December 2. Harvest or protect frost-sensitive crops — tomatoes, peppers, basil, squash — before this date.
How long is the growing season in San Diego County?
San Diego County has a frost-free growing season of approximately 199 days. This is enough time for most warm-season crops including tomatoes, peppers, and squash with proper timing. Climate records show the growing season is trending shorter by about 4.57 days per decade.
What is the soil like in San Diego County for gardening?
San Diego County has predominantly Loam soil with a pH range of 5.7–7.5 and Well Drained drainage. Most vegetables and herbs grow well with standard composting and seasonal soil amendment.
What is grown commercially in San Diego County?
San Diego County has commercial agriculture that includes Lettuce, Broccoli, Strawberries. These crops reflect the local climate and soil conditions — what succeeds commercially often translates well to home gardens in the same area.
Is San Diego County a good location for home gardening?
San Diego County scores 39/100 (Challenging) 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.
Your San Diego County Garden Planner — Free
A 24-page printable planner built for San Diego County (Zone 10b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.
The Gardener's Encyclopedia to Companion Planting
The pairings that make vegetables, herbs, and flowers grow better — and the ones that quietly wreck a bed.
- Proven pairings for 200+ vegetables, herbs, flowers, and fruits
- Full seed-starting + planting schedule with timing and spacing
- Bonus: square-foot gardening guide + printable seasonal planners
Seed Saving & Storage Guide
Most saved seeds go bad before next season. This shows exactly when to pick, how to dry, and where to store seeds from 200 plants so yours don't.
- 200 plants, step-by-step: life cycle, pollination type, isolation
- Exact temperature + humidity ranges that keep seeds viable
- Bonus: searchable Google Sheets tracker + custom GPT assistant
Composting Guide for Homesteaders
Turn kitchen scraps and yard waste into compost that actually feeds the garden — instead of a pile that smells, attracts pests, and never breaks down.
- 14 sections on composting methods, soil science, and troubleshooting
- The 7-step hot-compost system from start to finish
- Bonus tools: troubleshooting chart, safety guide, monitoring log