When to Plant Bitter Melon in San Francisco County, CA
Your May gardening checklist
We've pulled the most time-sensitive tasks for San Francisco County, California this May and put them front and centre. Tackle them in order.
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It's harvest week for bitter melon
Check every 1–2 days. Many of these get tough or go to seed if you wait too long.
A few tasks this May that'll pay off in June
- First harvests: bitter melon
Bitter melon is a tropical vine producing warty, bitter fruits used in Asian and Indian cuisine. The intense bitterness is prized for its culinary and health properties.
San Francisco County, California is in USDA Zone 10b. The average last spring frost is February 23 and the first fall frost is November 27, giving you a growing season of approximately 277 days.
At an elevation of 412 feet, San Francisco County receives approximately 13.5 inches of rainfall annually with predominantly loam soil. Summer highs average 86°F, providing good warmth for Bitter Melon during the growing season. With low rainfall, drip irrigation is essential for growing Bitter Melon successfully. Mulch heavily to conserve soil moisture.
San Francisco County Soil Profile
Soil Type
Loam
Soil pH
6.2-7.2
Drainage
Well Drained
Plant Planting Risk Windows
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 San Francisco County
How your county's soil matches Bitter Melon's growing requirements.
Soil pH
Your soil pH (6.2–7.2) overlaps with Bitter Melon's range (6.0–7.0), though not a perfect match.
Soil Texture
The loam soil in San Francisco County is excellent for Bitter Melon — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (3.0%). Annual compost additions will help Bitter Melon.
How to Plant Bitter Melon
Succession Planting Bitter Melon
Sow every 6.9 weeks. Last sowing by Aug 29 to harvest before frost.
Plant Water Budget
Water stress score is 8/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Bitter Melon
Bitter Melon needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Bitter Melon Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 2.3" | 0" | ❄️ Dormant |
| Feb | 4.3" | 3.1" | 1.2" | 💧 Light watering |
| Mar | 4.3" | 2.2" | 2.1" | 💧 Light watering |
| Apr | 4.3" | 1.2" | 3.1" | 🚿 Regular watering |
| May | 4.3" | 0.3" | 4" | 🚿 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" | 0.1" | 4.2" | 🚿 Regular watering |
| Oct | 4.3" | 0.6" | 3.7" | 🚿 Regular watering |
| Nov | 4.3" | 1.4" | 2.9" | 🚿 Regular watering |
| Dec | — | 2.1" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Feb–Nov in San Francisco County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Bitter Melon 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.
Bitter Melon Planting Timeline — San Francisco County, CA
Bitter Melon Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | January 12 | Jan 12 – Jan 26 |
| Transplant Outdoors | March 2 | Mar 2 – Mar 16 |
| Direct Sow | February 23 | Feb 23 – Mar 16 |
| Harvest | May 4 | May 4 – Jun 15 |
Plant 1" deep · 30" apart · Rows 42" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors |
| February | Direct Sow |
| March | Transplant Outdoors Direct Sow |
| April | — |
| May | Harvest |
| June | Harvest |
| July | — |
| August | — |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1"/week · 2-3 times/week
📅 Days to Maturity
60–90 days
🧪 Soil pH
Needs 6–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 10b
📆 Growing Season
277 days in San Francisco County
Growing Tips for Bitter Melon in San Francisco County
Direct sow Bitter Melon outdoors after February 23 in San Francisco County when soil has warmed and frost danger has passed.
Common pests for Bitter Melon in this region include squash vine borer and cucumber beetles. Use row covers early in the season and inspect plants weekly.
San Francisco County receives only 14" of rain annually. Bitter Melon needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.
General growing tips
Start seeds indoors 4 weeks before last frost. Provide a trellis for climbing. Harvest fruits while still green and firm. Reduce bitterness by salting sliced fruit before cooking.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Bitter Melon in Other Locations
Frequently Asked Questions
When should I plant Bitter Melon in San Francisco County, CA?
San Francisco County is in Zone 10b with an average last frost of February 23. Plan your Bitter Melon planting based on this frost date — see the calendar above for exact timing.
What planting zone is San Francisco County, CA?
San Francisco County, California is in USDA Hardiness Zone 10b. The average last spring frost is February 23 and first fall frost is November 27.
Your San Francisco County Garden Planner — Free
A 24-page printable planner built for San Francisco 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.