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When to Plant Valerian in Cerro Gordo County, IA

Cerro Gordo County, Iowa Zone 5a May

May to-do list for Cerro Gordo County, Iowa

Each item below is timed to Cerro Gordo County, Iowa's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost May 1
Avg. first frost October 7
Soil temp (4") 56°F
Watering Low
Pest pressure Low
Daylight 14.5 hrs
  1. Time to transplant valerian

    Harden off for 7 days — a little more sun each day — before planting. That's the difference between a seedling that thrives and one that stalls.

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Valerian is a tall perennial herb with fragrant white or pink flower clusters, valued for its root which is used as a natural sleep aid. It attracts pollinators and earthworms.

Cerro Gordo County, Iowa is in USDA Zone 5a. The average last spring frost is May 1 and the first fall frost is October 7, giving you a growing season of approximately 159 days.

At an elevation of 692 feet, Cerro Gordo County receives approximately 38.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80°F, so choose short-season varieties of Valerian to ensure they mature before fall.

Cerro Gordo County, IA (Zone 5a) Moderate season
159 days
Last Spring Frost May 1
159 growing days
First Fall Frost October 7
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Cerro Gordo County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-7.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: May 2 🍅 Harvest: Sep 5 – Oct 17
Recommended (50%) ✗ May not fit
Transplant: May 8 🍅 Harvest: Sep 11 – Oct 23
Safe Start (90%) ✗ May not fit
Transplant: May 22 🍅 Harvest: Sep 25 – Nov 6

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 Cerro Gordo County

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

Soil pH

Your soil pH (5.7–7.3) overlaps with Valerian's range (5.5–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.5%) — Valerian will thrive.

How to Plant Valerian

0.5"
Planting Depth
8"
Between Plants
12"
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 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Valerian

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

Month Valerian Needs Rainfall You Supplement Action
Jan 1.4" 0" ❄️ Dormant
Feb 1.9" 0" ❄️ Dormant
Mar 2.3" 0" ❄️ Dormant
Apr 3.9" 0" ❄️ Dormant
May 4.3" 5.1" 0" ✅ Rainfall sufficient
Jun 4.3" 4.5" 0" ✅ Rainfall sufficient
Jul 4.3" 4.4" 0" ✅ Rainfall sufficient
Aug 4.3" 4.1" 0.2" 💧 Light watering
Sep 4.3" 3.5" 0.8" 💧 Light watering
Oct 4.3" 2.6" 1.7" 💧 Light watering
Nov 2.7" 0" ❄️ Dormant
Dec 1.9" 0" ❄️ Dormant

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

Valerian 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.

Valerian needs ~1,500 GDD — county provides 1,590 GDD Good fit

Valerian Planting Timeline — Cerro Gordo County, IA

Valerian Planting Calendar

Activity When Date Range
Transplant Outdoors May 8 May 8 – May 22
Harvest September 11 Sep 11 – Oct 23

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

Month-by-Month Timeline

MonthActivities
January
February
March
April
May Transplant Outdoors
June
July
August
September Harvest
October Harvest
November
December
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Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

120–180 days

🧪 Soil pH

Needs 5.5–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 5a

📆 Growing Season

159 days in Cerro Gordo County

Growing Tips for Valerian in Cerro Gordo County

Direct sow Valerian outdoors after May 01 in Cerro Gordo County when soil has warmed and frost danger has passed.

Your 159.0-day growing season in Cerro Gordo County is tight for Valerian (120.0-180.0 days to maturity). Start indoors and choose early-maturing varieties.

General growing tips

Start seeds indoors and transplant after last frost. Harvest roots in fall of the second year. Deadhead flowers unless you want self-seeding. Cats are attracted to valerian root.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Valerian in Cerro Gordo County, IA?

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

What planting zone is Cerro Gordo County, IA?

Cerro Gordo County, Iowa is in USDA Hardiness Zone 5a. The average last spring frost is May 1 and first fall frost is October 7.

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Your Cerro Gordo County Garden Planner — Free

A 24-page printable planner built for Cerro Gordo 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 Cerro Gordo County, IA. Local conditions may vary. Last updated: May 2026.

Sources & credits

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