Blog

When to Plant Mustard Greens in Pottawattamie County, IA

Pottawattamie County, Iowa Zone 5b May

May in Pottawattamie County, Iowa — your action list

Your garden in Pottawattamie County, Iowa is working on a schedule, even when you're not. Here's where you should be this May.

Avg. last frost April 30
Avg. first frost October 3
Soil temp (4") 59°F
Watering Low
Pest pressure Low
Daylight 14.3 hrs
Coming up in June — start thinking about
  • Starting indoors: mustard greens
  • First harvests: mustard greens

Instant PDF download. No spam, unsubscribe any time.

Mustard greens are fast-growing brassicas with a spicy, peppery kick. They come in green, red, and purple varieties and are excellent cooked or in salads.

Pottawattamie County, Iowa is in USDA Zone 5b. The average last spring frost is April 30 and the first fall frost is October 3, giving you a growing season of approximately 156 days.

At an elevation of 518 feet, Pottawattamie County receives approximately 33.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Mustard Greens during the growing season.

Pottawattamie County, IA (Zone 5b) Moderate season
156 days
Last Spring Frost April 30
156 growing days
First Fall Frost October 3
Share this guide:

Pottawattamie 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 (57 days to spare)
Start indoors: Mar 19 Transplant: Apr 23 🍅 Harvest: May 28 – Jul 30
Recommended (50%) ✓ Fits season (58 days to spare)
Start indoors: Mar 26 Transplant: Apr 30 🍅 Harvest: Jun 4 – Aug 6
Safe Start (90%) ✓ Fits season (55 days to spare)
Start indoors: Apr 10 Transplant: May 15 🍅 Harvest: Jun 19 – Aug 21

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 Pottawattamie County

How your county's soil matches Mustard Greens's growing requirements.

Soil pH

Your soil pH (6.1–6.9) is within Mustard Greens's preferred range (6.0–7.0).

Soil Texture

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

Organic Matter

Organic matter is excellent (5.0%) — Mustard Greens will thrive.

How to Plant Mustard Greens

0.5"
Planting Depth
6"
Between Plants
12"
Between Rows

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

Succession Planting Mustard Greens

6
successive plantings in your 156-day season

Sow every 3.4 weeks. Last sowing by Aug 14 to harvest before frost.

For a dedicated fall crop, sow by Jul 25.

Plant Water Budget

Plant needs
0.7″/week
Rainfall provides
0.9″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Mustard Greens

Mustard Greens needs approximately 0.7 inches of water per week (3" per month). Here's how your county's rainfall compares month by month.

Month Mustard Greens Needs Rainfall You Supplement Action
Jan 1.4" 0" ❄️ Dormant
Feb 1.3" 0" ❄️ Dormant
Mar 2.2" 0" ❄️ Dormant
Apr 3" 3.2" 0" ✅ Rainfall sufficient
May 3" 3.9" 0" ✅ Rainfall sufficient
Jun 3" 4.3" 0" ✅ Rainfall sufficient
Jul 3" 4" 0" ✅ Rainfall sufficient
Aug 3" 3.5" 0" ✅ Rainfall sufficient
Sep 3" 2.7" 0.3" 💧 Light watering
Oct 3" 2.3" 0.7" 💧 Light watering
Nov 2.4" 0" ❄️ Dormant
Dec 2" 0" ❄️ Dormant

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

Mustard Greens 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.

Mustard Greens needs ~610 GDD — county provides 2,379 GDD Excellent fit

Mustard Greens Planting Timeline — Pottawattamie County, IA

Mustard Greens 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 June 4 Jun 4 – Aug 6
Fall Sowing July 25 Jul 25 – Aug 8

Plant 0.5" deep · 6" 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 Harvest
July Fall Sowing Harvest
August Fall Sowing Harvest
September
October
November
December
Share this guide:

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

0.7"/week · Natural rainfall sufficient

📅 Days to Maturity

30–50 days

🧪 Soil pH

Needs 6–7 · Your soil: ideal

🗺️ USDA Zone

Zone 5b

📆 Growing Season

156 days in Pottawattamie County

Growing Tips for Mustard Greens in Pottawattamie County

Direct sow Mustard Greens outdoors after April 30 in Pottawattamie County when soil has warmed and frost danger has passed.

Your generous 156.0-day season in Pottawattamie County allows multiple plantings of Mustard Greens. Sow every 15.0 days for continuous harvest.

Common pests for Mustard Greens in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

Direct sow in early spring or fall. Harvest young leaves for milder flavor. Plants bolt quickly in heat so grow as a cool-season crop or provide shade.

Companion Planting

Good Companions

Avoid Planting Near

  • Strawberries

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Mustard Greens in Pottawattamie County, IA?

Pottawattamie County is in Zone 5b with an average last frost of April 30. Plan your Mustard Greens planting based on this frost date — see the calendar above for exact timing.

What planting zone is Pottawattamie County, IA?

Pottawattamie County, Iowa is in USDA Hardiness Zone 5b. The average last spring frost is April 30 and first fall frost is October 3.

🌱

Your Pottawattamie County Garden Planner — Free

A 24-page printable planner built for Pottawattamie County (Zone 5b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Pottawattamie 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.