When to plant Leeks in Needles, CA
In Needles, plant Leeks in spring between February 3 and February 24, once soil temps hold above 50°F. Needles's last frost averages February 24, so aim for a steady week of warm soil before planting. For a fall crop, sow between September 30 and October 14 — roughly 90–150 days before the first frost on November 25.
When to Plant Leeks in Needles, CA
Top priorities for San Bernardino County, California gardeners in June
If you only do a handful of things in the garden this June, make it these. They're sequenced around your zone's frost timing.
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Start harvesting leeks
Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.
Coming up in July — start thinking about
- 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.
Needles, California is in USDA Zone 10a. The average last spring frost is February 24 and the first fall frost is November 25, giving you a growing season of approximately 274 days.
At an elevation of 1,012 feet, San Bernardino County receives approximately 16.9 inches of rainfall annually with predominantly loam soil. Summer highs average 97°F, so Leeks may need afternoon shade and extra watering during peak heat. With low rainfall, drip irrigation is essential for growing Leeks successfully. Mulch heavily to conserve soil moisture.
Needles Soil Profile
Soil Type
Loam
Soil pH
5.9-7.2
Drainage
Well Drained
Leeks 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 Needles
How your county's soil matches Leeks's growing requirements.
Soil pH
Your soil pH (5.9–7.2) overlaps with Leeks's range (6.0–7.0), though not a perfect match.
Soil Texture
The loam soil in San Bernardino County is excellent for Leeks — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.4%). Annual compost additions will help Leeks.
How to Plant Leeks
Fall planting: Sow 8 weeks before your first frost date for a fall harvest.
Leeks Water Budget
Water stress score is 10/10 — 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 | — | 3.2" | 0" | ❄️ Dormant |
| Feb | 3.5" | 3.8" | 0" | ✅ Rainfall sufficient |
| Mar | 3.5" | 2.2" | 1.3" | 💧 Light watering |
| Apr | 3.5" | 1.5" | 2" | 🚿 Regular watering |
| May | 3.5" | 0.5" | 3" | 🚿 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" | 0.2" | 3.3" | 🚿 Regular watering |
| Oct | 3.5" | 0.7" | 2.8" | 🚿 Regular watering |
| Nov | 3.5" | 1.7" | 1.8" | 🚿 Regular watering |
| Dec | — | 3" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Feb–Nov in San Bernardino 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 — Needles, CA
Leeks Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | January 27 | Jan 27 – Feb 10 |
| Transplant Outdoors | February 24 | Feb 24 – Mar 10 |
| Direct Sow | February 3 | Feb 3 – Feb 24 |
| Harvest | May 26 | May 26 – Aug 11 |
| Fall Sowing | September 30 | Sep 30 – Oct 14 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors |
| February | Start Indoors Transplant Outdoors Direct Sow |
| March | Transplant Outdoors |
| April | — |
| May | Harvest |
| 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 · 1-2 times/week
📅 Days to Maturity
90–150 days
🧪 Soil pH
Needs 6–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 10a
📆 Growing Season
274 days in San Bernardino County
Growing Tips for Leeks in Needles
Direct sow Leeks outdoors after February 24 in San Bernardino County when soil has warmed and frost danger has passed.
With summer highs reaching 97°F in San Bernardino County, provide afternoon shade for Leeks and water deeply in the morning.
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
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Check more plant combinations with our Companion Planting Checker →
Leeks in Other Locations
When should I plant Leeks in Needles, CA?
In Needles, CA, plant Leeks after the last frost (around February 24) and before the first frost (around November 25). Best results when soil holds above 50°F.
What growing zone is Needles, CA for Leeks?
Needles sits in USDA Zone 10a. Leeks grows reliably in zones 3a through 10b, so it's a good fit here.
Can Leeks grow in Needles's climate?
Yes — Leeks grows well in Needles's temperate climate. Needles averages a 275-day frost-free season, with last frost around February 24 and first frost around November 25.
Your San Bernardino County Garden Planner — Free
A 22-page printable planner built for San Bernardino County (Zone 10a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.