When to Plant Lima Beans in Contra Costa County, CA
May to-do list for Contra Costa County, California
Your Contra Costa County, California garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.
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It's harvest week for lima beans
Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.
To set up a strong June, finish these tasks
- First harvests: lima beans
Lima beans are a warm-season legume producing large, creamy beans with a buttery texture. Both bush and pole varieties are available, with pole types yielding more.
Contra Costa County, California is in USDA Zone 9b. The average last spring frost is February 26 and the first fall frost is November 29, giving you a growing season of approximately 276 days.
At an elevation of 88 feet, Contra Costa County receives approximately 19 inches of rainfall annually with predominantly loam soil. Summer highs average 93°F, providing good warmth for Lima Beans during the growing season. With low rainfall, drip irrigation is essential for growing Lima Beans successfully. Mulch heavily to conserve soil moisture.
Contra Costa County Soil Profile
Soil Type
Loam
Soil pH
6.7-7.8
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 Contra Costa County
How your county's soil matches Lima Beans's growing requirements.
Soil pH
Your soil pH (6.7–7.8) is more alkaline than Lima Beans prefers (6.0–7.0). Add sulfur or peat moss to lower pH.
Soil Texture
The loam soil in Contra Costa County is excellent for Lima Beans — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (3.0%). Annual compost additions will help Lima Beans.
How to Plant Lima Beans
Succession Planting Lima Beans
Sow every 6.9 weeks. Last sowing by Aug 31 to harvest before frost.
Plant Water Budget
Water stress score is 8/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Lima Beans
Lima Beans needs approximately 0.9 inches of water per week (3.9" per month). Here's how your county's rainfall compares month by month.
| Month | Lima Beans Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 4.1" | 0" | ❄️ Dormant |
| Feb | 3.9" | 4.5" | 0" | ✅ Rainfall sufficient |
| Mar | 3.9" | 3" | 0.9" | 💧 Light watering |
| Apr | 3.9" | 1.5" | 2.4" | 🚿 Regular watering |
| May | 3.9" | 0.6" | 3.3" | 🚿 Regular watering |
| Jun | 3.9" | 0.1" | 3.8" | 🚿 Regular watering |
| Jul | 3.9" | 0" | 3.9" | 🚿 Regular watering |
| Aug | 3.9" | 0" | 3.9" | 🚿 Regular watering |
| Sep | 3.9" | 0.2" | 3.7" | 🚿 Regular watering |
| Oct | 3.9" | 0.7" | 3.2" | 🚿 Regular watering |
| Nov | 3.9" | 1.6" | 2.3" | 🚿 Regular watering |
| Dec | — | 2.7" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Feb–Nov in Contra Costa County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Lima Beans 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.
Lima Beans Planting Timeline — Contra Costa County, CA
Lima Beans Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Direct Sow | March 5 | Mar 5 – Mar 26 |
| Harvest | May 7 | May 7 – Jun 18 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Direct Sow |
| April | — |
| May | Harvest |
| June | Harvest |
| July | — |
| August | — |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.9"/week · 2-3 times/week
📅 Days to Maturity
60–90 days
🧪 Soil pH
Needs 6–7 · Your soil: too_alkaline
🗺️ USDA Zone
Zone 9b
📆 Growing Season
276 days in Contra Costa County
Growing Tips for Lima Beans in Contra Costa County
Direct sow Lima Beans outdoors after February 26 in Contra Costa County when soil has warmed and frost danger has passed.
Common pests for Lima Beans in this region include bean beetles and aphids. Use row covers early in the season and inspect plants weekly.
Contra Costa County receives only 19" of rain annually. Lima Beans needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.
General growing tips
Direct sow after soil is thoroughly warm at 65F or above. Do not soak seeds before planting as they may crack. Harvest when pods are plump but still green for fresh limas.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Lima Beans in Other Locations
Frequently Asked Questions
When should I plant Lima Beans in Contra Costa County, CA?
Contra Costa County is in Zone 9b with an average last frost of February 26. Plan your Lima Beans planting based on this frost date — see the calendar above for exact timing.
What planting zone is Contra Costa County, CA?
Contra Costa County, California is in USDA Hardiness Zone 9b. The average last spring frost is February 26 and first fall frost is November 29.
Your Contra Costa County Garden Planner — Free
A 24-page printable planner built for Contra Costa 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.