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When to Plant Angelica in Platte County, WY

Platte County, Wyoming Zone 5a May

Your May planting checklist for Platte County, Wyoming

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

Avg. last frost May 13
Avg. first frost September 26
Soil temp (4") 35°F
Watering High
Pest pressure Low
Daylight 14.4 hrs
  1. Plant out angelica

    Pick a cloudy afternoon or evening to plant. Less transplant shock, and your seedlings will barely blink.

Looking ahead to 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.

Platte County, Wyoming is in USDA Zone 5a. The average last spring frost is May 13 and the first fall frost is September 26, giving you a growing season of approximately 136 days.

At an elevation of 7,409 feet, Platte County receives approximately 18.5 inches of rainfall annually with predominantly loam soil. Summer highs average 83°F, so choose short-season varieties of Angelica to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Angelica successfully. Mulch heavily to conserve soil moisture.

Platte County, WY (Zone 5a) Short season
136 days
Last Spring Frost May 13
136 growing days
First Fall Frost September 26
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Platte County Soil Profile

Soil Type

Loam

Soil pH

6.5-8.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season
Start indoors: Apr 6 Transplant: May 4
Recommended (50%) ✓ Fits season
Start indoors: Apr 8 Transplant: May 6
Safe Start (90%) ✓ Fits season
Start indoors: Apr 20 Transplant: May 18

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 Platte County

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

Soil pH

Your soil pH (6.5–8.3) is more alkaline than Angelica prefers (5.5–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.9%). Annual compost additions will help Angelica.

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
0.6″/week
You supply
1.1″/week
Watering frequency 2-3 times/week
Season total 1,349 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — 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 1.3" 0" ❄️ Dormant
Feb 1" 0" ❄️ Dormant
Mar 1.7" 0" ❄️ Dormant
Apr 2.2" 0" ❄️ Dormant
May 6.5" 2" 4.5" 🚿 Regular watering
Jun 6.5" 1.5" 5" 🚿 Regular watering
Jul 6.5" 1.5" 5" 🚿 Regular watering
Aug 6.5" 2" 4.5" 🚿 Regular watering
Sep 6.5" 1.3" 5.2" 🚿 Regular watering
Oct 1.5" 0" ❄️ Dormant
Nov 1.3" 0" ❄️ Dormant
Dec 1.1" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Platte 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 ~6,707 GDD — county provides 1,666 GDD May not mature

Angelica Planting Timeline — Platte County, WY

Angelica Planting Calendar

Activity When Date Range
Start Indoors April 8 Apr 8 – Apr 22
Transplant Outdoors May 6 May 6 – May 20
Direct Sow April 29 Apr 29 – May 20
Fall Sowing July 18 Jul 18 – Aug 1

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

Month-by-Month Timeline

MonthActivities
January
February
March
April Start Indoors 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: too_alkaline

🗺️ USDA Zone

Zone 5a

📆 Growing Season

136 days in Platte County

Growing Tips for Angelica in Platte County

Direct sow Angelica outdoors after May 13 in Platte County when soil has warmed and frost danger has passed.

Your 136.0-day growing season in Platte 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.

Platte County receives only 18" of rain annually. Angelica needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

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 Platte County, WY?

Platte County is in Zone 5a with an average last frost of May 13. Plan your Angelica planting based on this frost date — see the calendar above for exact timing.

What planting zone is Platte County, WY?

Platte County, Wyoming is in USDA Hardiness Zone 5a. The average last spring frost is May 13 and first fall frost is September 26.

🌱

Your Platte County Garden Planner — Free

A 24-page printable planner built for Platte 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 Platte County, WY. 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.