Blog

When to Plant Raspberries in Carroll County, IA

Raspberries are beloved bramble fruits producing sweet, delicate berries in red, golden, black, and purple varieties. They spread by underground runners and are very productive.

Carroll County, Iowa is in USDA Zone 5a. The average last spring frost is April 27 and the first fall frost is October 5, giving you a growing season of approximately 161 days.

At an elevation of 751 feet, Carroll County receives approximately 38.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87ยฐF, providing good warmth for Raspberries during the growing season.

Carroll County, IA (Zone 5a) Moderate season
161 days
Last Spring Frost April 27
161 growing days
First Fall Frost October 5

Carroll County Soil Profile

Soil Type

Silt Loam

Soil pH

6.1-6.9

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season
Transplant: May 13
Recommended (50%) ✓ Fits season
Transplant: May 18
Safe Start (90%) ✓ Fits season
Transplant: Jun 1

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 Carroll County

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

Soil pH

Your soil pH (6.1โ€“6.9) overlaps with Raspberries's range (5.5โ€“6.5), though not a perfect match.

Soil Texture

The silt loam soil in Carroll County is excellent for Raspberries โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (5.1%) โ€” Raspberries will thrive.

How to Plant Raspberries

24"
Between Plants
72"
Between Rows

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” consider drought-tolerant varieties and mulching

Monthly Watering Guide for Raspberries

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

Month Raspberries Needs Rainfall You Supplement Action
Jan โ€” 1.6" 0" โ„๏ธ Dormant
Feb โ€” 1.6" 0" โ„๏ธ Dormant
Mar โ€” 2.8" 0" โ„๏ธ Dormant
Apr 4.3" 4.2" 0.1" ๐Ÿ’ง Light watering
May 4.3" 4.6" 0" โœ… Rainfall sufficient
Jun 4.3" 4.9" 0" โœ… Rainfall sufficient
Jul 4.3" 3.6" 0.7" ๐Ÿ’ง Light watering
Aug 4.3" 4.2" 0.1" ๐Ÿ’ง Light watering
Sep 4.3" 3.5" 0.8" ๐Ÿ’ง Light watering
Oct 4.3" 3" 1.3" ๐Ÿ’ง Light watering
Nov โ€” 2.9" 0" โ„๏ธ Dormant
Dec โ€” 1.8" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Oct in Carroll County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Raspberries 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" โ€” every day above 50ยฐF 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.

Raspberries needs ~8,349 GDD — county provides 2,455 GDD May not mature

Raspberries Planting Timeline โ€” Carroll County, IA

Raspberries Planting Calendar

Activity When Date Range
Transplant Outdoors May 18 May 18 โ€“ Jun 1

ยท 24" apart ยท Rows 72" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April โ€”
May Transplant Outdoors
June Transplant Outdoors
July โ€”
August โ€”
September โ€”
October โ€”
November โ€”
December โ€”

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

365โ€“730 days

๐Ÿงช Soil pH

Needs 5.5โ€“6.5 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 5a

๐Ÿ“† Growing Season

161 days in Carroll County

Growing Tips for Raspberries in Carroll County

Direct sow Raspberries outdoors after April 27 in Carroll County when soil has warmed and frost danger has passed.

Your 161.0-day growing season in Carroll County is tight for Raspberries (365.0-730.0 days to maturity). Start indoors and choose early-maturing varieties.

General growing tips

Provide a trellis for support. Prune summer-bearing types by removing spent canes after harvest. For ever-bearing types, mow all canes in late winter for a single fall crop.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes
  • Tomatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Raspberries in Carroll County, IA?

Carroll County is in Zone 5a with an average last frost of April 27. Plan your Raspberries planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Carroll County, IA?

Carroll County, Iowa is in USDA Hardiness Zone 5a. The average last spring frost is April 27 and first fall frost is October 5.

๐ŸŒฑ

Plan Your Garden with Confidence

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

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

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