When to Plant Leeks in Tompkins County, NY
Your August planting checklist for Tompkins County, New York
Each item below is timed to Tompkins County, New York's frost dates and soil temperatures. Skip nothing, stress about nothing.
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Harvest leeks as they ripen
Check every 1–2 days. Many of these get tough or go to seed if you wait too long.
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Direct-sow leeks for cool weather
Your first frost is about 9 weeks away — plenty of time for these to mature.
Before September arrives, get these ready
- 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.
Tompkins County, New York is in USDA Zone 6a. The average last spring frost is May 10 and the first fall frost is October 11, giving you a growing season of approximately 154 days.
At an elevation of 309 feet, Tompkins County receives approximately 40.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Leeks during the growing season.
Tompkins County Soil Profile
Soil Type
Silt Loam
Soil pH
5.2-6.4
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 Tompkins County
How your county's soil matches Leeks's growing requirements.
Soil pH
Your soil pH (5.2–6.4) is more acidic than Leeks prefers (6.0–7.0). Add garden lime to raise pH.
Soil Texture
The silt loam soil in Tompkins County is excellent for Leeks — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (3.6%). Annual compost additions will help Leeks.
How to Plant Leeks
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Leeks Water Budget
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 | — | 2.8" | 0" | ❄️ Dormant |
| Mar | — | 3.4" | 0" | ❄️ Dormant |
| Apr | — | 3.3" | 0" | ❄️ Dormant |
| May | 3.5" | 3.3" | 0.2" | 💧 Light watering |
| Jun | 3.5" | 3.8" | 0" | ✅ Rainfall sufficient |
| Jul | 3.5" | 4.4" | 0" | ✅ Rainfall sufficient |
| Aug | 3.5" | 3.5" | 0" | ✅ Rainfall sufficient |
| Sep | 3.5" | 3.8" | 0" | ✅ Rainfall sufficient |
| Oct | 3.5" | 2.9" | 0.6" | 💧 Light watering |
| Nov | — | 3.5" | 0" | ❄️ Dormant |
| Dec | — | 2.6" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in Tompkins 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 — Tompkins County, NY
Leeks Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 5 | Apr 5 – Apr 19 |
| Transplant Outdoors | May 10 | May 10 – May 24 |
| Direct Sow | April 26 | Apr 26 – May 17 |
| Harvest | August 9 | Aug 9 – Oct 25 |
| Fall Sowing | August 2 | Aug 2 – Aug 16 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | — |
| July | — |
| August | Fall Sowing Harvest |
| September | Harvest |
| October | Harvest |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.8"/week · Natural rainfall sufficient
📅 Days to Maturity
90–150 days
🧪 Soil pH
Needs 6–7 · Your soil: too_acidic
🗺️ USDA Zone
Zone 6a
📆 Growing Season
154 days in Tompkins County
Growing Tips for Leeks in Tompkins County
Direct sow Leeks outdoors after May 10 in Tompkins County when soil has warmed and frost danger has passed.
Your 154.0-day growing season in Tompkins County is tight for Leeks (90.0-150.0 days to maturity). Start indoors and choose early-maturing varieties.
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 Tompkins County, NY?
Tompkins County is in Zone 6a with an average last frost of May 10. Plan your Leeks planting based on this frost date — see the calendar above for exact timing.
What planting zone is Tompkins County, NY?
Tompkins County, New York is in USDA Hardiness Zone 6a. The average last spring frost is May 10 and first fall frost is October 11.
Your Tompkins County Garden Planner — Free
A 22-page printable planner built for Tompkins County (Zone 6a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.