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When to Plant Angelica in Palo Alto County, IA

Palo Alto County, Iowa Zone 5a May

Palo Alto County, Iowa gardeners: here's your May plan

May is a pivotal month for Palo Alto County, Iowa gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost April 27
Avg. first frost October 8
Soil temp (4") 54°F
Watering Low
Pest pressure Low
Daylight 14.5 hrs
A few tasks this May that'll pay off in June
  • Starting indoors: angelica

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Angelica is a dramatic biennial herb that can reach 6 feet tall with large compound leaves and globe-shaped flower clusters. All parts are edible with a sweet, celery-like flavor.

Palo Alto County, Iowa is in USDA Zone 5a. The average last spring frost is April 27 and the first fall frost is October 8, giving you a growing season of approximately 164 days.

At an elevation of 1,358 feet, Palo Alto County receives approximately 34.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 81°F, so choose short-season varieties of Angelica to ensure they mature before fall.

Palo Alto County, IA (Zone 5a) Moderate season
164 days
Last Spring Frost April 27
164 growing days
First Fall Frost October 8
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Palo Alto 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
Start indoors: Mar 17 Transplant: Apr 14
Recommended (50%) ✓ Fits season
Start indoors: Mar 23 Transplant: Apr 20
Safe Start (90%) ✓ Fits season
Start indoors: Apr 9 Transplant: May 7

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 Palo Alto County

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

Soil pH

Your soil pH (6.1–6.9) is within Angelica's preferred range (5.5–7.0).

Soil Texture

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

Organic Matter

Organic matter is excellent (4.8%) — Angelica will thrive.

How to Plant Angelica

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
1.5″/week
Rainfall provides
0.9″/week
You supply
0.7″/week
Watering frequency 2-3 times/week
Season total 1,071 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Angelica

Angelica needs approximately 1.5 inches of water per week (6.5" per month). Here's how your county's rainfall compares month by month.

Month Angelica Needs Rainfall You Supplement Action
Jan 1.6" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 2.8" 0" ❄️ Dormant
Apr 6.5" 3.5" 3" 💧 Light watering
May 6.5" 4.4" 2.1" 💧 Light watering
Jun 6.5" 4.1" 2.4" 💧 Light watering
Jul 6.5" 4.1" 2.4" 💧 Light watering
Aug 6.5" 3.2" 3.3" 🚿 Regular watering
Sep 6.5" 2.8" 3.7" 🚿 Regular watering
Oct 6.5" 2.9" 3.6" 🚿 Regular watering
Nov 2.2" 0" ❄️ Dormant
Dec 1.8" 0" ❄️ Dormant

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

Angelica 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.

Angelica needs ~5,886 GDD — county provides 1,763 GDD May not mature

Angelica Planting Timeline — Palo Alto County, IA

Angelica Planting Calendar

Activity When Date Range
Start Indoors March 23 Mar 23 – Apr 6
Transplant Outdoors April 20 Apr 20 – May 4
Direct Sow April 13 Apr 13 – May 4
Fall Sowing July 30 Jul 30 – Aug 13

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
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Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1.5"/week · 2-3 times/week

📅 Days to Maturity

365–730 days

🧪 Soil pH

Needs 5.5–7 · Your soil: ideal

🗺️ USDA Zone

Zone 5a

📆 Growing Season

164 days in Palo Alto County

Growing Tips for Angelica in Palo Alto County

Direct sow Angelica outdoors after April 27 in Palo Alto County when soil has warmed and frost danger has passed.

Your 164.0-day growing season in Palo Alto County is tight for Angelica (365.0-730.0 days to maturity). Start indoors and choose early-maturing varieties.

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

General growing tips

Sow fresh seeds in fall for spring germination. Provide rich, moist soil and partial shade. Harvest stems in the second year before flowering for candying or flavoring.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Angelica in Palo Alto County, IA?

Palo Alto County is in Zone 5a with an average last frost of April 27. Plan your Angelica planting based on this frost date — see the calendar above for exact timing.

What planting zone is Palo Alto County, IA?

Palo Alto County, Iowa is in USDA Hardiness Zone 5a. The average last spring frost is April 27 and first fall frost is October 8.

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Your Palo Alto County Garden Planner — Free

A 24-page printable planner built for Palo Alto 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 Palo Alto 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.