When to Plant Borage in Monterey County, CA
Your May gardening checklist
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.
-
It's harvest week for borage
The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.
To set up a strong June, finish these tasks
- 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.
Monterey County, California is in USDA Zone 9b. The average last spring frost is March 13 and the first fall frost is November 17, giving you a growing season of approximately 249 days.
At an elevation of 260 feet, Monterey County receives approximately 12.5 inches of rainfall annually with predominantly loam soil. Summer highs average 93°F, providing good warmth for Borage during the growing season. With low rainfall, drip irrigation is essential for growing Borage successfully. Mulch heavily to conserve soil moisture.
Monterey County Soil Profile
Soil Type
Loam
Soil pH
6.7-7.2
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 Monterey County
How your county's soil matches Borage's growing requirements.
Soil pH
Your soil pH (6.7–7.2) overlaps with Borage's range (6.0–7.0), though not a perfect match.
Soil Texture
The loam soil in Monterey County is excellent for Borage — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.7%). 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 18 to harvest before frost.
For a dedicated fall crop, sow by Sep 22.
Plant Water Budget
Water stress score is 8/10 — 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 | — | 2.7" | 0" | ❄️ Dormant |
| Feb | — | 2.6" | 0" | ❄️ Dormant |
| Mar | 2.2" | 2.1" | 0.1" | 💧 Light watering |
| Apr | 2.2" | 1" | 1.2" | 🚿 Regular watering |
| May | 2.2" | 0.3" | 1.9" | 🚿 Regular watering |
| Jun | 2.2" | 0.1" | 2.1" | 🚿 Regular watering |
| Jul | 2.2" | 0" | 2.2" | 🚿 Regular watering |
| Aug | 2.2" | 0" | 2.2" | 🚿 Regular watering |
| Sep | 2.2" | 0.1" | 2.1" | 🚿 Regular watering |
| Oct | 2.2" | 0.5" | 1.7" | 🚿 Regular watering |
| Nov | 2.2" | 1.2" | 1" | 💧 Light watering |
| Dec | — | 1.9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Mar–Nov in Monterey 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 — Monterey County, CA
Borage Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 13 | Feb 13 – Feb 27 |
| Transplant Outdoors | March 6 | Mar 6 – Mar 20 |
| Direct Sow | February 20 | Feb 20 – Mar 13 |
| Harvest | May 1 | May 1 – Jun 19 |
| Fall Sowing | September 22 | Sep 22 – Oct 6 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors Direct Sow |
| March | Transplant Outdoors Direct Sow |
| April | — |
| May | Harvest |
| June | Harvest |
| July | — |
| August | — |
| September | Fall Sowing |
| October | Fall Sowing |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.5"/week · 1-2 times/week
📅 Days to Maturity
50–60 days
🧪 Soil pH
Needs 6–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 9b
📆 Growing Season
249 days in Monterey County
Growing Tips for Borage in Monterey County
Direct sow Borage outdoors after March 13 in Monterey 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 Monterey County, CA?
Monterey County is in Zone 9b with an average last frost of March 13. Plan your Borage planting based on this frost date — see the calendar above for exact timing.
What planting zone is Monterey County, CA?
Monterey County, California is in USDA Hardiness Zone 9b. The average last spring frost is March 13 and first fall frost is November 17.
Your Monterey County Garden Planner — Free
A 24-page printable planner built for Monterey 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.