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When to Plant Lentils in Jasper County, IA

Lentils are an ancient pulse crop producing small, lens-shaped seeds packed with protein and iron. They grow on short, bushy plants and are surprisingly easy to cultivate.

Jasper County, Iowa is in USDA Zone 5a. The average last spring frost is May 2 and the first fall frost is October 7, giving you a growing season of approximately 158 days.

At an elevation of 1,048 feet, Jasper County receives approximately 38 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85ยฐF, providing good warmth for Lentils during the growing season.

Jasper County, IA (Zone 5a) Moderate season
158 days
Last Spring Frost May 2
158 growing days
First Fall Frost October 7

Jasper County Soil Profile

Soil Type

Silt Loam

Soil pH

6-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (36 days to spare)
Start indoors: Mar 18 Transplant: Apr 22 🍅 Harvest: Jul 15 – Aug 26
Recommended (50%) ✓ Fits season (32 days to spare)
Start indoors: Mar 28 Transplant: May 2 🍅 Harvest: Jul 25 – Sep 5
Safe Start (90%) ✓ Fits season (28 days to spare)
Start indoors: Apr 10 Transplant: May 15 🍅 Harvest: Aug 7 – Sep 18

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.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
1.0″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Lentils needs ~1,306 GDD — county provides 2,172 GDD Excellent fit

Lentils Planting Timeline โ€” Jasper County, IA

Lentils Planting Calendar

Activity When Date Range
Start Indoors March 28 Mar 28 โ€“ Apr 11
Transplant Outdoors May 2 May 2 โ€“ May 16
Direct Sow April 18 Apr 18 โ€“ May 9
Fall Sowing July 29 Jul 29 โ€“ Aug 12
Harvest July 25 Jul 25 โ€“ Sep 5

Plant 0.5" deep ยท 6" apart ยท Rows 12" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March Start Indoors
April Start Indoors Direct Sow
May Transplant Outdoors Direct Sow
June โ€”
July Fall Sowing Harvest
August Fall Sowing Harvest
September Harvest
October โ€”
November โ€”
December โ€”

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Low โ€” drought tolerant

Days to Maturity

80โ€“110 days

Soil pH

6 โ€“ 8

USDA Zone

Zone 5a

Growing Season

158 days

Growing Tips for Jasper County

Direct sow in early spring as lentils tolerate frost. Provide short supports as plants tend to lodge. Harvest when lower pods turn brown. Pull entire plants and dry in bundles.

Companion Planting

Good Companions

Avoid Planting Near

  • Onion
  • Garlic

Level Up Your Garden

Frequently Asked Questions

When should I plant Lentils in Jasper County, IA?

Jasper County is in Zone 5a with an average last frost of May 2. Plan your Lentils planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Jasper County, IA?

Jasper County, Iowa is in USDA Hardiness Zone 5a. The average last spring frost is May 2 and first fall frost is October 7.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Jasper County gardeners in Zone 5a organize planting dates, track what's growing, and never miss a planting window.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Jasper County, IA. Local conditions may vary. Last updated: April 2026.