Imperial County, CA — Planting Guide
May in Imperial County, California — your action list
If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.
-
Pick basil, cucumber, and green beans
The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.
Get ahead of June
- First harvests: basil, peppers, and thai basil
Imperial County is in USDA Zone 10a. The average last spring frost is January 29 and the first fall frost is December 20, giving you a growing season of approximately 326 days.
At an elevation of 181 ft, Imperial County receives approximately 16.8 in of rainfall annually. Summer highs average 93°F with winter lows around 59°F. The predominant soil type is Loam.
Based on 12 years of NOAA climate station data, the last frost date here varies by 41 days year to year — ranging from January 4 in warm years to February 14 in cold years. The growing season is trending longer by about 9.89 days per decade. Imperial County scores 40/100 (Moderate) on the Microclimate Index.
🌡️ Zone
10a (°F to °F min)
❄️ Last Frost
January 29
🍂 First Frost
December 20
📅 Growing Season
326 days
⛰️ Elevation
181 ft
🌧️ Annual Rainfall
16.8 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 | 3.3 in | 11 days | 1 in | Moderate |
| Mar | 3.1 in | 8 days | 1.2 in | Moderate |
| Apr | 1.4 in | 4 days | 2.9 in | High |
| May | 0.4 in | 1 days | 3.9 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 | 1 days | 4.1 in | Critical |
| Oct | 0.6 in | 3 days | 3.7 in | Critical |
| Nov | 1.5 in | 6 days | 2.8 in | High |
| Dec | 3.3 in | 10 days | 1 in | Moderate |
Annual total: 16.9 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.
Imperial County Soil Profile
Soil Type
Loam
Soil pH
5.7-7.3
Drainage
Well Drained
Frost Risk Probability
Based on 12 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) | Feb 14 | Dec 27 | 316 days |
| Cautious | Feb 4 | Dec 26 | 325 days |
| Average year | Jan 29 | Dec 20 | 325 days |
| Optimistic | Jan 16 | Dec 15 | 333 days |
| Aggressive (risky) | Jan 4 | Nov 29 | 329 days |
Not very — frost dates can vary by ±41 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 longer here (about 9.9 days per decade). Spring is arriving earlier than it used to. Good news for gardeners.
Gardening Difficulty Score
Imperial County presents some gardening challenges. Choose adapted varieties and plan around frost dates.
Local Gardening Help in Imperial 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 Imperial County's climate and soil.
County Extension Office
Imperial 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 Imperial County
Finding local nurseries & garden centers in Imperial County
Why Buy Local
Local nurseries carry plants that are proven to grow in your area. Staff can give you advice specific to Imperial 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 Imperial County CA" or "garden center Imperial 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 Imperial County CA" or check your extension office and local parks department. Facebook groups like "Imperial 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 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 | 5.5 hr | Short day |
| February | 10.8 hr | 6.3 hr | Short day |
| March | 11.8 hr | 7.4 hr | Short day |
| April | 12.8 hr | 9.5 hr | Neutral |
| May | 13.7 hr | 11.4 hr | Neutral |
| June | 14.2 hr | 12.5 hr | Long day |
| July | 14 hr | 13 hr | Long day |
| August | 13.2 hr | 11.8 hr | Neutral |
| September | 12.2 hr | 10 hr | Neutral |
| October | 11.2 hr | 8 hr | Short day |
| November | 10.3 hr | 6.1 hr | Short day |
| December | 9.8 hr | 5.6 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 Dec.
Best Month to Compost
Mar
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 | 56°F | 63°F | ♻️ Active | ~14 weeks |
| Feb | 58°F | 65°F | ♻️ Active | ~14 weeks |
| Mar | 66°F | 67°F | 🔥 Peak | ~8 weeks |
| Apr | 72°F | 71°F | 🔥 Peak | ~8 weeks |
| May | 78°F | 77°F | 🔥 Peak | ~8 weeks |
| Jun | 86°F | 86°F | 🔥 Peak | ~8 weeks |
| Jul | 93°F | 90°F | 🔥 Peak | ~8 weeks |
| Aug | 94°F | 91°F | 🔥 Peak | ~8 weeks |
| Sep | 90°F | 90°F | 🔥 Peak | ~8 weeks |
| Oct | 81°F | 84°F | 🔥 Peak | ~8 weeks |
| Nov | 70°F | 77°F | 🔥 Peak | ~8 weeks |
| Dec | 64°F | 69°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 Imperial County
Computed from local climate patterns — warmer, humid conditions increase pest generations and fungal disease risk.
Insect Pest Pressure
High — expect multiple pest generations. Preventative measures essential.
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 | Low | 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 Imperial 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 | Feb 1 | Oct 25 | — | Rapid growth, attracts pollinators, suppresses weeds |
| Cowpeas (southern peas) | Feb 8 | Oct 25 | ✓ Yes | Excellent nitrogen fixer for warm climates, edible |
| Sorghum-sudan grass | Jan 30 | Oct 18 | — | Massive biomass, breaks compaction, suppresses nematodes |
| White clover | Jan 4 | Oct 18 | ✓ 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 9 | Nov 29 | — | 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 | Oct 15 | Jan 15 | ✓ 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: 9 mph
Fall: 7 mph Winter: 9 mph
Prevailing wind: W. Moderate wind — consider a temporary windbreak for young seedlings.
Windbreak Benefit
3.4/10
Low need — wind is not a major factor in your garden planning.
Frost Pocket Risk
Moderate
Some terrain variation (630 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
8,422 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 16.9 inches of rain per year
- A 1,000 sq ft roof can collect roughly 8,422 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 Imperial County
Soil Type
Loam
Soil pH 5.7–7.3 · Well Drained drainage
Native soil is well-suited to most vegetables and herbs with regular compost additions.
Watering Needs
Drought stress: 9.5/10
Very high drought stress. Irrigation is critical for garden success. Focus on water-efficient techniques and drought-adapted crops.
Season Tips
326-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.
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 Imperial County
106 vegetables that grow well in Zone 10a with planting dates for Imperial County.
Show all 106 vegetables with planting dates
| Plant | Start Indoors | Direct Sow | Transplant | Harvest | Days to Maturity |
|---|---|---|---|---|---|
| Acorn Squash | Jan 1 | Jan 29 | Feb 5 | Apr 30 – Jun 4 | 80–100 |
| Amaranth | Dec 18 | Jan 29 | Feb 5 | May 7 – Jun 25 | 90–120 |
| Artichoke | — | — | Feb 12 | Jun 18 – Aug 27 | 120–180 |
| Arugula | Jan 1 | Jan 8 | Jan 29 | Mar 5 – May 7 | 30–50 |
| Asparagus | — | — | Feb 12 | — | 730–1095 |
| Beets | — | Jan 8 | — | Mar 5 – Apr 2 | 50–70 |
| Belgian Endive | Jan 1 | Jan 8 | Jan 29 | May 21 – Jul 16 | 110–150 |
| Bitter Melon | Dec 18 | Jan 29 | Feb 5 | Apr 9 – May 21 | 60–90 |
| Black Beans | — | Feb 5 | — | May 7 – Jun 25 | 90–120 |
| Bok Choy | Jan 1 | Jan 8 | Jan 29 | Mar 12 – Apr 16 | 40–60 |
| Broccoli | Jan 1 | Jan 8 | Jan 29 | Apr 2 – May 14 | 60–90 |
| Broccoli Rabe | Jan 1 | Jan 8 | Jan 29 | Mar 12 – Apr 16 | 40–60 |
| Brussels Sprouts | Jan 1 | Jan 8 | Jan 29 | Apr 30 – Jun 25 | 90–130 |
| Butternut Squash | Jan 1 | Jan 29 | Feb 5 | May 7 – Jun 11 | 85–110 |
| Cabbage | Jan 1 | Jan 8 | Jan 29 | Apr 2 – May 28 | 60–100 |
| Calabash | Dec 18 | Jan 29 | Feb 5 | Apr 30 – Jun 25 | 80–120 |
| Cardoon | — | — | Feb 12 | Jun 18 – Jul 30 | 120–150 |
| Carrots | — | Jan 8 | — | Mar 12 – Apr 16 | 60–80 |
| Cauliflower | Jan 1 | Jan 8 | Jan 29 | Mar 26 – May 28 | 55–100 |
| Celery | Jan 1 | Jan 8 | Jan 29 | Apr 23 – Jun 18 | 80–120 |
| Celtuce | Jan 1 | Jan 8 | Jan 29 | Apr 2 – May 14 | 60–90 |
| Chard | Jan 1 | Jan 8 | Jan 29 | Mar 26 – May 14 | 50–60 |
| Chayote | Dec 18 | Jan 29 | Feb 5 | Jun 11 – Aug 20 | 120–180 |
| Chickpeas | Jan 1 | Jan 8 | Jan 29 | Apr 23 – Jun 4 | 80–110 |
| Chicory | Jan 1 | Jan 8 | Jan 29 | Apr 2 – May 14 | 60–85 |
| Chinese Cabbage | Jan 1 | Jan 8 | Jan 29 | Mar 26 – Apr 23 | 50–70 |
| Christmas Lima Beans | Dec 18 | Jan 29 | Feb 5 | Apr 30 – Jun 4 | 80–100 |
| Collard Greens | Jan 1 | Jan 8 | Jan 29 | Mar 26 – May 28 | 55–75 |
| Corn | — | Feb 5 | — | Apr 9 – Jun 4 | 60–100 |
| Cowpeas | — | Feb 5 | — | Apr 9 – May 21 | 60–90 |
| Cress | Jan 1 | Jan 8 | Jan 29 | Feb 12 – Mar 5 | 14–21 |
| Crookneck Squash | Jan 1 | Jan 29 | Feb 5 | Mar 26 – Apr 23 | 45–60 |
| Cucumber | Jan 1 | Jan 29 | Feb 5 | Apr 2 – May 28 | 50–70 |
| Daikon | — | Jan 8 | — | Mar 5 – Apr 2 | 50–70 |
| Delicata Squash | Jan 1 | Jan 29 | Feb 5 | Apr 30 – Jun 4 | 80–100 |
| Edamame | — | Feb 5 | — | Apr 23 – Jun 4 | 75–100 |
| Eggplant | Dec 18 | Jan 29 | Feb 5 | Apr 16 – Jun 18 | 65–85 |
| Endive | Jan 1 | Jan 8 | Jan 29 | Mar 19 – Apr 23 | 45–65 |
| Escarole | Jan 1 | Jan 8 | Jan 29 | Mar 26 – Apr 23 | 50–70 |
| Fava Beans | Jan 1 | Jan 8 | Jan 29 | Apr 16 – May 28 | 75–100 |
| Fennel | Dec 18 | Jan 29 | Feb 5 | Apr 9 – May 21 | 60–90 |
| Ginger | Dec 18 | Jan 29 | Feb 5 | Oct 8 – Dec 17 | 240–300 |
| Green Beans | — | Feb 5 | — | Apr 2 – May 28 | 50–65 |
| Hot Peppers | Dec 18 | Jan 29 | Feb 5 | Apr 16 – Jul 23 | 70–120 |
| Hubbard Squash | Jan 1 | Jan 29 | Feb 5 | May 21 – Jun 25 | 100–120 |
| Jicama | Dec 18 | Jan 29 | Feb 5 | Jun 11 – Aug 20 | 120–180 |
| Kabocha | Jan 1 | Jan 29 | Feb 5 | May 7 – Jun 4 | 85–100 |
| Kai Lan | Jan 1 | Jan 8 | Jan 29 | Mar 19 – Apr 16 | 45–60 |
| Kale | Jan 1 | Jan 8 | Jan 29 | Mar 26 – May 21 | 50–70 |
| Kidney Beans | — | Feb 5 | — | May 7 – Jun 11 | 85–110 |
| Kohlrabi | Jan 1 | Jan 8 | Jan 29 | Mar 19 – Apr 23 | 45–65 |
| Komatsuna | Jan 1 | Jan 8 | Jan 29 | Mar 5 – Apr 9 | 35–50 |
| Leeks | Jan 1 | Jan 8 | Jan 29 | Apr 30 – Jul 16 | 90–150 |
| Lentils | Jan 1 | Jan 8 | Jan 29 | Apr 23 – Jun 4 | 80–110 |
| Lettuce | Jan 1 | Jan 8 | Jan 29 | Mar 5 – May 14 | 30–60 |
| Lima Beans | — | Feb 5 | — | Apr 9 – May 21 | 60–90 |
| Loofah | Dec 18 | Jan 29 | Feb 5 | May 21 – Jul 23 | 100–150 |
| Luffa | Dec 18 | Jan 29 | Feb 5 | May 7 – Jul 23 | 90–150 |
| Mache | Jan 1 | Jan 8 | Jan 29 | Mar 12 – Apr 16 | 40–60 |
| Malabar Spinach | Dec 18 | Jan 29 | Feb 5 | Apr 2 – Apr 30 | 55–70 |
| Melon | Jan 1 | Jan 29 | Feb 5 | Apr 16 – Jun 4 | 70–100 |
| Microgreens | Jan 1 | Jan 8 | Jan 29 | Feb 5 – Mar 5 | 7–21 |
| Mizuna | Jan 1 | Jan 8 | Jan 29 | Mar 5 – Apr 2 | 30–45 |
| Mustard Greens | Jan 1 | Jan 8 | Jan 29 | Mar 5 – May 7 | 30–50 |
| Napa Cabbage | Jan 1 | Jan 8 | Jan 29 | Mar 26 – Apr 30 | 55–75 |
| New Zealand Spinach | Dec 18 | Jan 29 | Feb 5 | Apr 2 – Apr 30 | 55–70 |
| Okra | Dec 18 | Jan 29 | Feb 5 | Apr 2 – May 28 | 50–65 |
| Onion | Jan 1 | Jan 8 | Jan 29 | Apr 30 – Jun 18 | 90–120 |
| Pac Choi | Jan 1 | Jan 8 | Jan 29 | Mar 12 – Apr 9 | 40–55 |
| Patty Pan Squash | Jan 1 | Jan 29 | Feb 5 | Mar 26 – Apr 23 | 45–60 |
| Peas | Jan 1 | Jan 8 | Jan 29 | Mar 26 – May 21 | 55–70 |
| Peppers | Dec 18 | Jan 29 | Feb 5 | Apr 9 – Jun 18 | 60–90 |
| Pole Beans | Dec 18 | Jan 29 | Feb 5 | Apr 2 – May 28 | 55–70 |
| Potatoes | Dec 18 | Jan 29 | Feb 5 | Apr 16 – Jun 25 | 70–120 |
| Pumpkin | Jan 1 | Jan 29 | Feb 5 | May 7 – Jun 25 | 85–120 |
| Purslane | Jan 1 | Jan 8 | Jan 29 | Mar 12 – Apr 16 | 40–60 |
| Radicchio | Jan 1 | Jan 8 | Jan 29 | Apr 2 – May 7 | 60–80 |
| Radish | — | Jan 8 | — | Feb 5 – Feb 26 | 22–35 |
| Romanesco | Jan 1 | Jan 8 | Jan 29 | Apr 16 – May 28 | 75–100 |
| Savoy Cabbage | Jan 1 | Jan 8 | Jan 29 | Apr 9 – Jun 4 | 70–110 |
| Scallions | Jan 1 | Jan 8 | Jan 29 | Mar 26 – Apr 23 | 50–70 |
| Scarlet Runner Beans | Dec 18 | Jan 29 | Feb 5 | Apr 9 – May 14 | 60–80 |
| Shallot | Jan 1 | Jan 8 | Jan 29 | Apr 30 – Jun 18 | 90–120 |
| Shiso | Dec 18 | Feb 5 | Feb 5 | Apr 2 – May 28 | 50–70 |
| Snap Peas | Dec 18 | Jan 29 | Feb 5 | Apr 2 – May 28 | 55–70 |
| Snow Peas | Jan 1 | Jan 8 | Jan 29 | Mar 26 – May 21 | 50–65 |
| Soybeans | — | Feb 5 | — | Apr 30 – Jun 25 | 80–120 |
| Spaghetti Squash | Jan 1 | Jan 29 | Feb 5 | May 7 – Jun 4 | 85–100 |
| Spinach | Jan 1 | Jan 8 | Jan 29 | Mar 5 – May 7 | 35–50 |
| Squash (Summer) | Jan 1 | Jan 29 | Feb 5 | Mar 26 – May 28 | 45–65 |
| Squash (Winter) | Jan 1 | Jan 29 | Feb 5 | Apr 30 – Jun 25 | 80–120 |
| Sunflower | Dec 18 | Jan 29 | Feb 5 | Apr 16 – Jun 4 | 70–100 |
| Sweet Corn | — | Feb 5 | — | Apr 9 – May 21 | 60–90 |
| Sweet Potatoes | Dec 18 | Jan 29 | Feb 5 | May 7 – Jun 25 | 90–120 |
| Tatsoi | Jan 1 | Jan 8 | Jan 29 | Mar 5 – Apr 9 | 35–50 |
| Tomatillo | Dec 18 | Jan 29 | Feb 5 | Apr 9 – Jun 18 | 60–85 |
| Tomatoes | Dec 18 | Jan 29 | Feb 5 | Apr 9 – Jun 18 | 60–85 |
| Turmeric | Dec 18 | Jan 29 | Feb 5 | Oct 8 – Dec 17 | 240–300 |
| Turnip | — | Jan 8 | — | Feb 19 – Mar 26 | 40–60 |
| Watercress | Jan 1 | Jan 8 | Jan 29 | Mar 12 – Apr 16 | 40–60 |
| Watermelon | Jan 1 | Jan 29 | Feb 5 | Apr 16 – Jun 4 | 70–100 |
| Wax Beans | — | Feb 5 | — | Apr 2 – May 28 | 50–65 |
| Winter Melon | Dec 18 | Jan 29 | Feb 5 | May 7 – Jun 25 | 90–120 |
| Yam | Dec 18 | Jan 29 | Feb 5 | Aug 6 – Jan 21 | 180–330 |
| Yard Long Beans | Dec 18 | Jan 29 | Feb 5 | Apr 2 – May 14 | 55–80 |
| Zucchini | Jan 1 | Jan 29 | Feb 5 | Mar 26 – May 21 | 45–60 |
🍓 Fruits to Grow in Imperial County
16 fruits that grow well in Zone 10a with planting dates for Imperial County.
Show all 16 fruits with planting dates
| Plant | Start Indoors | Direct Sow | Transplant | Harvest | Days to Maturity |
|---|---|---|---|---|---|
| Alpine Strawberries | — | — | Feb 12 | May 14 – Aug 27 | 90–180 |
| Blackberries | — | — | Feb 12 | — | 365–730 |
| Boysenberries | — | — | Feb 12 | — | 365–730 |
| Cantaloupe | — | — | Feb 12 | Apr 23 – May 28 | 70–90 |
| Che Fruit | — | — | Feb 12 | — | 1095–1825 |
| Dragon Fruit | — | — | Feb 12 | — | 365–730 |
| Figs | — | — | Feb 12 | — | 730–1825 |
| Goji Berries | — | — | Feb 12 | — | 730–1095 |
| Grapes | — | — | Feb 12 | — | 730–1095 |
| Ground Cherry | — | — | Feb 12 | Apr 23 – Jun 18 | 65–80 |
| Guava | — | — | Feb 12 | — | 365–730 |
| Honeydew | — | — | Feb 12 | May 7 – Jun 18 | 80–110 |
| Loquat | — | — | Feb 12 | — | 730–1825 |
| Passion Fruit | — | — | Feb 12 | — | 365–545 |
| Pomegranate | — | — | Feb 12 | — | 730–1095 |
| Strawberries | — | — | Feb 12 | May 14 – Feb 11 | 90–365 |
🌿 Herbs to Grow in Imperial County
23 herbs that grow well in Zone 10a with planting dates for Imperial County.
Show all 23 herbs with planting dates
| Plant | Start Indoors | Direct Sow | Transplant | Harvest | Days to Maturity |
|---|---|---|---|---|---|
| Anise | Jan 1 | Jan 8 | Jan 22 | Apr 23 – Jul 9 | 90–120 |
| Basil | Dec 18 | Feb 5 | Feb 5 | Apr 2 – Jun 4 | 50–75 |
| Borage | Jan 1 | Jan 8 | Jan 22 | Mar 19 – May 7 | 50–60 |
| Chervil | Jan 1 | Jan 8 | Jan 22 | Mar 5 – May 7 | 40–60 |
| Chives | — | — | Feb 5 | Apr 9 – Jun 18 | 60–90 |
| Cilantro | Jan 1 | Jan 8 | Jan 22 | Mar 5 – May 7 | 40–60 |
| Cumin | Jan 1 | Jan 8 | Jan 22 | May 7 – Jul 9 | 100–120 |
| Dill | Jan 1 | Jan 8 | Jan 22 | Mar 5 – May 7 | 40–60 |
| Epazote | Dec 18 | Feb 5 | Feb 5 | Mar 26 – May 21 | 45–60 |
| Fennel (herb) | Jan 1 | Jan 8 | Jan 22 | Mar 26 – Jun 4 | 60–90 |
| Garlic Chives | — | — | Feb 5 | Apr 9 – Jun 18 | 60–90 |
| Horehound | — | — | Feb 5 | Apr 23 – Jun 18 | 75–90 |
| Lemon Verbena | Dec 18 | Feb 5 | Feb 5 | Apr 9 – Jun 18 | 60–90 |
| Lemongrass | Dec 18 | Feb 5 | Feb 5 | Apr 23 – Jul 23 | 75–120 |
| Marjoram | — | — | Feb 5 | Apr 9 – Jun 18 | 60–90 |
| Mint | — | — | Feb 5 | Apr 9 – Jun 18 | 60–90 |
| Oregano | — | — | Feb 5 | Apr 9 – Jun 18 | 60–90 |
| Parsley | Jan 1 | Jan 8 | Jan 22 | Mar 26 – May 28 | 60–80 |
| Rosemary | — | — | Feb 5 | Apr 30 – Sep 17 | 80–180 |
| Sage | — | — | Feb 5 | Apr 23 – Jun 18 | 75–90 |
| Savory | — | — | Feb 5 | Apr 2 – May 28 | 50–70 |
| Stevia | Dec 18 | Feb 5 | Feb 5 | Apr 9 – Jun 18 | 60–90 |
| Thai Basil | Dec 18 | Feb 5 | Feb 5 | Apr 2 – Jun 4 | 50–75 |
Monthly Planting Guide for Imperial County
Gardening Guides & Resources
Helpful guides from The Ultimate Homestead to improve your garden in Imperial County.
Frequently Asked Questions
What planting zone is Imperial County, CA?
Imperial County is in USDA Hardiness Zone 10a. 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 Imperial County, CA?
Based on 12 years of NOAA weather station data, the median last spring frost in Imperial County falls around January 29. In 8 out of 10 years, last frost lands between January 4 and February 14 — a 41-day window of variability. Use February 14 as your conservative safe-to-plant date for frost-sensitive crops.
When is the first fall frost in Imperial County, CA?
The median first fall frost in Imperial County arrives around December 20. In cold years it can arrive as early as November 29; in mild years as late as December 27. Harvest or protect frost-sensitive crops — tomatoes, peppers, basil, squash — before this date.
How long is the growing season in Imperial County?
Imperial County has a frost-free growing season of approximately 326 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 9.89 days per decade.
What is the soil like in Imperial County for gardening?
Imperial County has predominantly Loam soil with a pH range of 5.7–7.3 and Well Drained drainage. Most vegetables and herbs grow well with standard composting and seasonal soil amendment.
What is grown commercially in Imperial County?
Imperial 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 Imperial County a good location for home gardening?
Imperial County scores 40/100 (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.
Your Imperial County Garden Planner — Free
A 24-page printable planner built for Imperial County (Zone 10a). 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