When to Plant Leeks in Monterey County, CA
May in the garden — Monterey County, California
Each item below is timed to Monterey County, California's frost dates and soil temperatures. Skip nothing, stress about nothing.
A few tasks this May that'll pay off in June
- First harvests: leeks
Leeks are a mild, sweet allium that produces long white shanks. They are more refined than onions and are a key ingredient in soups, stews, and gratins.
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 Leeks during the growing season. With low rainfall, drip irrigation is essential for growing Leeks 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 Leeks's growing requirements.
Soil pH
Your soil pH (6.7–7.2) overlaps with Leeks's range (6.0–7.0), though not a perfect match.
Soil Texture
The loam soil in Monterey County is excellent for Leeks — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.7%). Annual compost additions will help Leeks.
How to Plant Leeks
Fall planting: Sow 8 weeks before your first frost date for a fall harvest.
Plant Water Budget
Water stress score is 8/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Leeks
Leeks needs approximately 0.8 inches of water per week (3.5" per month). Here's how your county's rainfall compares month by month.
| Month | Leeks Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 2.7" | 0" | ❄️ Dormant |
| Feb | — | 2.6" | 0" | ❄️ Dormant |
| Mar | 3.5" | 2.1" | 1.4" | 💧 Light watering |
| Apr | 3.5" | 1" | 2.5" | 🚿 Regular watering |
| May | 3.5" | 0.3" | 3.2" | 🚿 Regular watering |
| Jun | 3.5" | 0.1" | 3.4" | 🚿 Regular watering |
| Jul | 3.5" | 0" | 3.5" | 🚿 Regular watering |
| Aug | 3.5" | 0" | 3.5" | 🚿 Regular watering |
| Sep | 3.5" | 0.1" | 3.4" | 🚿 Regular watering |
| Oct | 3.5" | 0.5" | 3" | 🚿 Regular watering |
| Nov | 3.5" | 1.2" | 2.3" | 🚿 Regular 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.
Leeks 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.
Leeks Planting Timeline — Monterey County, CA
Leeks Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 13 | Feb 13 – Feb 27 |
| Transplant Outdoors | March 13 | Mar 13 – Mar 27 |
| Direct Sow | February 20 | Feb 20 – Mar 13 |
| Harvest | June 12 | Jun 12 – Aug 28 |
| Fall Sowing | September 22 | Sep 22 – Oct 6 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors Direct Sow |
| March | Transplant Outdoors Direct Sow |
| April | — |
| May | — |
| June | Harvest |
| July | Harvest |
| August | Harvest |
| September | Fall Sowing |
| October | Fall Sowing |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.8"/week · 2-3 times/week
📅 Days to Maturity
90–150 days
🧪 Soil pH
Needs 6–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 9b
📆 Growing Season
249 days in Monterey County
Growing Tips for Leeks in Monterey County
Direct sow Leeks outdoors after March 13 in Monterey County when soil has warmed and frost danger has passed.
Common pests for Leeks in this region include onion maggots and thrips. Use row covers early in the season and inspect plants weekly.
General growing tips
Start seeds indoors 10-12 weeks before last frost. Transplant into trenches and hill soil around stems as they grow to increase the white portion. Harvest as needed.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Leeks in Other Locations
Frequently Asked Questions
When should I plant Leeks in Monterey County, CA?
Monterey County is in Zone 9b with an average last frost of March 13. Plan your Leeks 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.