When to Plant Borage in El Dorado County, CA
May in El Dorado County, California — your action list
Welcome to May in Zone 9b. These are the moves that will have the biggest impact on your growing season.
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Fire up the seed-starting tray: borage
Bottom-water once the first true leaves appear — it keeps stems dry and knocks back damping-off.
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Basket week: borage
Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.
Before June arrives, get these ready
- First harvests: borage
Borage is a self-seeding annual herb with star-shaped blue flowers that attract pollinators. Its leaves have a cucumber-like flavor and the flowers are edible.
El Dorado County, California is in USDA Zone 9b. The average last spring frost is April 11 and the first fall frost is November 22, giving you a growing season of approximately 225 days.
At an elevation of 2,714 feet, El Dorado County receives approximately 41 inches of rainfall annually with predominantly loam soil. Summer highs average 83°F, so choose short-season varieties of Borage to ensure they mature before fall.
El Dorado County Soil Profile
Soil Type
Loam
Soil pH
6.3-7.2
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 El Dorado County
How your county's soil matches Borage's growing requirements.
Soil pH
Your soil pH (6.3–7.2) overlaps with Borage's range (6.0–7.0), though not a perfect match.
Soil Texture
The loam soil in El Dorado County is excellent for Borage — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.9%). Annual compost additions will help Borage.
How to Plant Borage
Fall planting: Sow 8 weeks before your first frost date for a fall harvest.
Succession Planting Borage
Sow every 5.7 weeks. Last sowing by Sep 23 to harvest before frost.
For a dedicated fall crop, sow by Sep 27.
Plant Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Borage
Borage needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.
| Month | Borage Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 7.5" | 0" | ❄️ Dormant |
| Feb | — | 9.2" | 0" | ❄️ Dormant |
| Mar | — | 7" | 0" | ❄️ Dormant |
| Apr | 2.2" | 3.4" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 1.1" | 1.1" | 🚿 Regular watering |
| Jun | 2.2" | 0.2" | 2" | 🚿 Regular watering |
| Jul | 2.2" | 0" | 2.2" | 🚿 Regular watering |
| Aug | 2.2" | 0" | 2.2" | 🚿 Regular watering |
| Sep | 2.2" | 0.5" | 1.7" | 🚿 Regular watering |
| Oct | 2.2" | 1.6" | 0.6" | 💧 Light watering |
| Nov | 2.2" | 3.8" | 0" | ✅ Rainfall sufficient |
| Dec | — | 6.8" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Nov in El Dorado County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Borage 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.
Borage Planting Timeline — El Dorado County, CA
Borage Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 14 | Mar 14 – Mar 28 |
| Transplant Outdoors | April 4 | Apr 4 – Apr 18 |
| Direct Sow | March 21 | Mar 21 – Apr 11 |
| Harvest | May 30 | May 30 – Jul 18 |
| Fall Sowing | September 27 | Sep 27 – Oct 11 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors Direct Sow |
| April | Transplant Outdoors Direct Sow |
| May | Harvest |
| June | Harvest |
| July | Harvest |
| August | — |
| September | Fall Sowing |
| October | Fall Sowing |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.5"/week · Natural rainfall sufficient
📅 Days to Maturity
50–60 days
🧪 Soil pH
Needs 6–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 9b
📆 Growing Season
225 days in El Dorado County
Growing Tips for Borage in El Dorado County
Direct sow Borage outdoors after April 11 in El Dorado County when soil has warmed and frost danger has passed.
General growing tips
Direct sow in spring as borage does not transplant well. Allow some plants to go to seed for next year. Young leaves are best; older leaves become bristly.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Borage in Other Locations
Frequently Asked Questions
When should I plant Borage in El Dorado County, CA?
El Dorado County is in Zone 9b with an average last frost of April 11. Plan your Borage planting based on this frost date — see the calendar above for exact timing.
What planting zone is El Dorado County, CA?
El Dorado County, California is in USDA Hardiness Zone 9b. The average last spring frost is April 11 and first fall frost is November 22.
Your El Dorado County Garden Planner — Free
A 24-page printable planner built for El Dorado 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.