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When to Plant Calabash in Yolo County, CA

Yolo County, California Zone 9b May

Yolo County, California gardeners: here's your May plan

A quick May briefing for Yolo County, California gardeners — what's urgent, what's next, and what can wait.

Avg. last frost February 9
Avg. first frost December 3
Soil temp (4") 76°F
Watering Critical
Pest pressure High
Daylight 14.1 hrs
  1. Harvest calabash as they ripen

    Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.

Before June arrives, get these ready
  • First harvests: calabash

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Calabash (bottle gourd) is a tropical vine producing edible young fruits used in Asian and African cooking. Mature dried fruits serve as natural containers and utensils.

Yolo County, California is in USDA Zone 9b. The average last spring frost is February 9 and the first fall frost is December 3, giving you a growing season of approximately 297 days.

At an elevation of 163 feet, Yolo County receives approximately 27.7 inches of rainfall annually with predominantly loam soil. Summer highs average 95°F, so Calabash may need afternoon shade and extra watering during peak heat.

Yolo County, CA (Zone 9b) Year-round
297 days
Last Spring Frost February 9
297 growing days
First Fall Frost December 3

Yolo County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (158 days to spare)
Start indoors: Dec 14 Transplant: Feb 1 🍅 Harvest: Apr 26 – Jun 21
Recommended (50%) ✓ Fits season (150 days to spare)
Start indoors: Dec 29 Transplant: Feb 16 🍅 Harvest: May 11 – Jul 6
Safe Start (90%) ✓ Fits season (134 days to spare)
Start indoors: Jan 30 Transplant: Mar 20 🍅 Harvest: Jun 12 – Aug 7

Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.

Soil Compatibility in Yolo County

How your county's soil matches Calabash's growing requirements.

Soil pH

Your soil pH (6.7–7.8) overlaps with Calabash's range (6.0–7.5), though not a perfect match.

Soil Texture

The loam soil in Yolo County is excellent for Calabash — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.4%). Annual compost additions will help Calabash.

How to Plant Calabash

1"
Planting Depth
30"
Between Plants
42"
Between Rows

Succession Planting Calabash

4
successive plantings in your 297-day season

Sow every 9.1 weeks. Last sowing by Aug 05 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.4″/week
You supply
0.7″/week
Watering frequency 2-3 times/week
Season total 1,940 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Calabash

Calabash needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Calabash Needs Rainfall You Supplement Action
Jan 6" 0" ❄️ Dormant
Feb 4.3" 5.4" 0" ✅ Rainfall sufficient
Mar 4.3" 4" 0.3" 💧 Light watering
Apr 4.3" 2.3" 2" 💧 Light watering
May 4.3" 0.8" 3.5" 🚿 Regular watering
Jun 4.3" 0.1" 4.2" 🚿 Regular watering
Jul 4.3" 0" 4.3" 🚿 Regular watering
Aug 4.3" 0" 4.3" 🚿 Regular watering
Sep 4.3" 0.3" 4" 🚿 Regular watering
Oct 4.3" 1.1" 3.2" 🚿 Regular watering
Nov 4.3" 2.6" 1.7" 💧 Light watering
Dec 4.3" 5.1" 0" ✅ Rainfall sufficient

Water needs are for active growing months only (Feb–Dec in Yolo County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Calabash Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Calabash needs ~2,125 GDD — county provides 6,332 GDD Excellent fit

Calabash Planting Timeline — Yolo County, CA

Calabash Planting Calendar

Activity When Date Range
Start Indoors December 29 Dec 29 – Jan 12
Transplant Outdoors February 16 Feb 16 – Mar 2
Direct Sow February 9 Feb 9 – Mar 2
Harvest May 11 May 11 – Jul 6

Plant 1" deep · 30" apart · Rows 42" apart

Month-by-Month Timeline

MonthActivities
January Start Indoors
February Transplant Outdoors Direct Sow
March Transplant Outdoors Direct Sow
April
May Harvest
June Harvest
July Harvest
August
September
October
November
December Start Indoors

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 2-3 times/week

📅 Days to Maturity

80–120 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 9b

📆 Growing Season

297 days in Yolo County

Growing Tips for Calabash in Yolo County

Direct sow Calabash outdoors after February 09 in Yolo County when soil has warmed and frost danger has passed.

Common pests for Calabash in this region include squash vine borer and cucumber beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

Start seeds indoors 4 weeks early. Provide a very strong trellis for heavy fruits. Harvest young for cooking or let mature on the vine for crafts. Requires a long, warm season.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Calabash in Yolo County, CA?

Yolo County is in Zone 9b with an average last frost of February 9. Plan your Calabash planting based on this frost date — see the calendar above for exact timing.

What planting zone is Yolo County, CA?

Yolo County, California is in USDA Hardiness Zone 9b. The average last spring frost is February 9 and first fall frost is December 3.

🌱

Your Yolo County Garden Planner — Free

A 24-page printable planner built for Yolo County (Zone 9b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Yolo County, CA. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.