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When to Plant Caraway in Osceola County, IA

Osceola County, Iowa Zone 5a April

April in the garden — Osceola County, Iowa

Here's what deserves your attention in Osceola County, Iowa this month. Everything below is tailored to Zone 5a and timed around your local frost dates.

Avg. last frost May 1
Avg. first frost October 5
Soil temp (4") 42°F
Watering Moderate
Pest pressure Low
Daylight 13.2 hrs
  1. Transplant caraway outside

    Bring a watering can to the bed. Each transplant gets a drink the moment it's in the ground, not ten minutes later.

  2. Scatter caraway into prepared beds

    Mark the row. Birds and stray feet both have opinions about unmarked beds.

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Caraway is a biennial herb grown for its distinctive crescent-shaped seeds used in rye bread, sauerkraut, and European cuisine. The leaves and roots are also edible.

Osceola County, Iowa is in USDA Zone 5a. The average last spring frost is May 1 and the first fall frost is October 5, giving you a growing season of approximately 157 days.

At an elevation of 752 feet, Osceola County receives approximately 34.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80°F, so choose short-season varieties of Caraway to ensure they mature before fall.

Osceola County, IA (Zone 5a) Moderate season
157 days
Last Spring Frost May 1
157 growing days
First Fall Frost October 5

Osceola County Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-6.9

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season
Start indoors: Mar 19 Transplant: Apr 16
Recommended (50%) ✓ Fits season
Start indoors: Mar 27 Transplant: Apr 24
Safe Start (90%) ✓ Fits season
Start indoors: Apr 10 Transplant: May 8

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 Osceola County

How your county's soil matches Caraway's growing requirements.

Soil pH

Your soil pH (5.8–6.9) overlaps with Caraway's range (6.0–7.5), though not a perfect match.

Soil Texture

The silt loam soil in Osceola County is excellent for Caraway — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (5.1%) — Caraway will thrive.

How to Plant Caraway

0.5"
Planting Depth
8"
Between Plants
12"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 143 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Caraway

Caraway needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Caraway Needs Rainfall You Supplement Action
Jan 1.3" 0" ❄️ Dormant
Feb 1.3" 0" ❄️ Dormant
Mar 2.1" 0" ❄️ Dormant
Apr 3.5" 0" ❄️ Dormant
May 4.3" 4.4" 0" ✅ Rainfall sufficient
Jun 4.3" 3.7" 0.6" 💧 Light watering
Jul 4.3" 4.1" 0.2" 💧 Light watering
Aug 4.3" 3.9" 0.4" 💧 Light watering
Sep 4.3" 3.3" 1" 💧 Light watering
Oct 4.3" 2.4" 1.9" 💧 Light watering
Nov 2" 0" ❄️ Dormant
Dec 1.9" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Osceola County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Caraway 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.

Caraway needs ~4,075 GDD — county provides 1,570 GDD May not mature

Caraway Planting Timeline — Osceola County, IA

Caraway Planting Calendar

Activity When Date Range
Start Indoors March 27 Mar 27 – Apr 10
Transplant Outdoors April 24 Apr 24 – May 8
Direct Sow April 17 Apr 17 – May 8
Fall Sowing July 27 Jul 27 – Aug 10

Plant 0.5" deep · 8" apart · Rows 12" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

365–450 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 5a

📆 Growing Season

157 days in Osceola County

Growing Tips for Caraway in Osceola County

Direct sow Caraway outdoors after May 01 in Osceola County when soil has warmed and frost danger has passed.

Your 157.0-day growing season in Osceola County is tight for Caraway (365.0-450.0 days to maturity). Start indoors and choose early-maturing varieties.

Common pests for Caraway in this region include carrot rust fly and parsleyworm. Use row covers early in the season and inspect plants weekly.

General growing tips

Direct sow in spring or fall. Caraway produces seeds in its second year. Harvest seed heads when they turn brown. The young leaves can be used like parsley.

Companion Planting

Good Companions

Avoid Planting Near

  • Fennel

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Caraway in Osceola County, IA?

Osceola County is in Zone 5a with an average last frost of May 1. Plan your Caraway planting based on this frost date — see the calendar above for exact timing.

What planting zone is Osceola County, IA?

Osceola County, Iowa is in USDA Hardiness Zone 5a. The average last spring frost is May 1 and first fall frost is October 5.

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Your Osceola County Garden Planner — Free

A 24-page printable planner built for Osceola 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.

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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 Osceola County, IA. Local conditions may vary. Last updated: April 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.