When to plant Leeks in Worth County, IA
In Worth County, plant Leeks in spring between April 16 and May 7, once soil temps hold above 50°F. Worth County's last frost averages April 30, so time plantings around the expected last-frost window for best survival. For a fall crop, sow between July 29 and August 12 — roughly 90–150 days before the first frost on October 7.
When to Plant Leeks in Worth County, IA
Your June game plan for Worth County, Iowa
Your Worth County, Iowa garden is entering a new phase. Here's what's on the schedule for June and why each task matters now.
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Begin indoor sowing: leeks
Give them 6–8 weeks indoors before the last frost and you'll transplant into warm soil with seedlings that are already leaping.
To set up a strong July, finish these tasks
- First harvests: leeks
- Fall sowing: 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.
Worth County, Iowa is in USDA Zone 5a. The average last spring frost is April 30 and the first fall frost is October 7, giving you a growing season of approximately 160 days.
At an elevation of 886 feet, Worth County receives approximately 39.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Leeks to ensure they mature before fall.
Worth County Soil Profile
Soil Type
Silt Loam
Soil pH
6-7.3
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 Worth County
How your county's soil matches Leeks's growing requirements.
Soil pH
Your soil pH (6.0–7.3) overlaps with Leeks's range (6.0–7.0), though not a perfect match.
Soil Texture
The silt loam soil in Worth County is excellent for Leeks — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.9%) — Leeks will thrive.
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 | — | 1.7" | 0" | ❄️ Dormant |
| Feb | — | 1.6" | 0" | ❄️ Dormant |
| Mar | — | 2.8" | 0" | ❄️ Dormant |
| Apr | 3.5" | 3.7" | 0" | ✅ Rainfall sufficient |
| May | 3.5" | 5" | 0" | ✅ Rainfall sufficient |
| Jun | 3.5" | 4.9" | 0" | ✅ Rainfall sufficient |
| Jul | 3.5" | 4.2" | 0" | ✅ Rainfall sufficient |
| Aug | 3.5" | 4.5" | 0" | ✅ Rainfall sufficient |
| Sep | 3.5" | 3.4" | 0.1" | 💧 Light watering |
| Oct | 3.5" | 3.3" | 0.2" | 💧 Light watering |
| Nov | — | 2.9" | 0" | ❄️ Dormant |
| Dec | — | 1.9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Worth 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 — Worth County, IA
Leeks Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 26 | Mar 26 – Apr 9 |
| Transplant Outdoors | April 30 | Apr 30 – May 14 |
| Direct Sow | April 16 | Apr 16 – May 7 |
| Harvest | July 30 | Jul 30 – Oct 15 |
| Fall Sowing | July 29 | Jul 29 – Aug 12 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Start Indoors Transplant Outdoors Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | — |
| July | Fall Sowing Harvest |
| 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: acceptable
🗺️ USDA Zone
Zone 5a
📆 Growing Season
160 days in Worth County
Growing Tips for Leeks in Worth County
Direct sow Leeks outdoors after April 30 in Worth County when soil has warmed and frost danger has passed.
Your 160.0-day growing season in Worth 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
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Check more plant combinations with our Companion Planting Checker →
Leeks in Other Locations
Frequently Asked Questions
When should I plant Leeks in Worth County, IA?
Worth County is in Zone 5a with an average last frost of April 30. Plan your Leeks planting based on this frost date — see the calendar above for exact timing.
What planting zone is Worth County, IA?
Worth County, Iowa is in USDA Hardiness Zone 5a. The average last spring frost is April 30 and first fall frost is October 7.
When should I plant Leeks in Worth County, IA?
In Worth County, IA, plant Leeks after the last frost (around April 30) and before the first frost (around October 7). Best results when soil holds above 50°F.
What growing zone is Worth County, IA for Leeks?
Worth County sits in USDA Zone 5a. Leeks grows reliably in zones 3a through 10b, so it's a good fit here.
Can Leeks grow in Worth County's climate?
Yes — Leeks grows well in Worth County's temperate climate. Worth County averages a 160-day frost-free season, with last frost around April 30 and first frost around October 7.
Your Worth County Garden Planner — Free
A 22-page printable planner built for Worth County (Zone 5a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.