Blog

When to Plant Cilantro in Natrona County, WY

Natrona County, Wyoming Zone 5a May

May in Natrona County, Wyoming — your action list

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

Avg. last frost May 19
Avg. first frost September 23
Soil temp (4") 38°F
Watering High
Pest pressure Low
Daylight 14.5 hrs
  1. Move cilantro into the garden

    Water the tray well an hour before you transplant. Roots slide out cleanly and settle in faster.

  2. Outdoor sowing time: cilantro

    These tolerate cool soil, so you're not gambling by sowing now.

June prep starts now
  • Starting indoors: cilantro
  • First harvests: cilantro

Instant PDF download. No spam, unsubscribe any time.

Cilantro is a dual-purpose herb providing fresh leaves (cilantro) and dried seeds (coriander). It bolts quickly in heat, producing flowers beloved by beneficial insects.

Natrona County, Wyoming is in USDA Zone 5a. The average last spring frost is May 19 and the first fall frost is September 23, giving you a growing season of approximately 127 days.

At an elevation of 6,332 feet, Natrona County receives approximately 13.7 inches of rainfall annually with predominantly loam soil. Summer highs average 83°F, so choose short-season varieties of Cilantro to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Cilantro successfully. Mulch heavily to conserve soil moisture.

Natrona County, WY (Zone 5a) Short season
127 days
Last Spring Frost May 19
127 growing days
First Fall Frost September 23
Share this guide:

Natrona County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (30 days to spare)
Start indoors: Apr 7 Transplant: May 5 🍅 Harvest: Jun 16 – Aug 18
Recommended (50%) ✓ Fits season (29 days to spare)
Start indoors: Apr 14 Transplant: May 12 🍅 Harvest: Jun 23 – Aug 25
Safe Start (90%) ✓ Fits season (31 days to spare)
Start indoors: Apr 28 Transplant: May 26 🍅 Harvest: Jul 7 – Sep 8

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 Natrona County

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

Soil pH

Your soil pH (6.5–7.6) is more alkaline than Cilantro prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.4%). Annual compost additions will help Cilantro.

How to Plant Cilantro

0.5"
Planting Depth
8"
Between Plants
12"
Between Rows

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

Succession Planting Cilantro

3
successive plantings in your 127-day season

Sow every 4.6 weeks. Last sowing by Jul 25 to harvest before frost.

For a dedicated fall crop, sow by Jul 15.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.5″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 64 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Cilantro

Cilantro needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.

Month Cilantro Needs Rainfall You Supplement Action
Jan 0.9" 0" ❄️ Dormant
Feb 0.8" 0" ❄️ Dormant
Mar 1.4" 0" ❄️ Dormant
Apr 1.3" 0" ❄️ Dormant
May 2.2" 1.8" 0.4" 💧 Light watering
Jun 2.2" 1.1" 1.1" 🚿 Regular watering
Jul 2.2" 1.1" 1.1" 🚿 Regular watering
Aug 2.2" 1.5" 0.7" 💧 Light watering
Sep 2.2" 1.1" 1.1" 🚿 Regular watering
Oct 1.1" 0" ❄️ Dormant
Nov 0.9" 0" ❄️ Dormant
Dec 0.7" 0" ❄️ Dormant

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

Cilantro 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.

Cilantro needs ~612 GDD — county provides 1,555 GDD Excellent fit

Cilantro Planting Timeline — Natrona County, WY

Cilantro Planting Calendar

Activity When Date Range
Start Indoors April 14 Apr 14 – Apr 28
Transplant Outdoors May 12 May 12 – May 26
Direct Sow May 5 May 5 – May 26
Harvest June 23 Jun 23 – Aug 25
Fall Sowing July 15 Jul 15 – Jul 29

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

Month-by-Month Timeline

MonthActivities
January
February
March
April Start Indoors
May Transplant Outdoors Direct Sow
June Harvest
July Fall Sowing Harvest
August Harvest
September
October
November
December
Share this guide:

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

0.5"/week · Only during dry spells

📅 Days to Maturity

40–60 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 5a

📆 Growing Season

127 days in Natrona County

Growing Tips for Cilantro in Natrona County

Direct sow Cilantro outdoors after May 19 in Natrona County when soil has warmed and frost danger has passed.

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

General growing tips

Succession sow every 2-3 weeks. Provide afternoon shade in warm weather. Harvest leaves before flowering or allow some plants to go to seed for coriander and self-sowing.

Companion Planting

Good Companions

Avoid Planting Near

  • Fennel

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Cilantro in Natrona County, WY?

Natrona County is in Zone 5a with an average last frost of May 19. Plan your Cilantro planting based on this frost date — see the calendar above for exact timing.

What planting zone is Natrona County, WY?

Natrona County, Wyoming is in USDA Hardiness Zone 5a. The average last spring frost is May 19 and first fall frost is September 23.

🌱

Your Natrona County Garden Planner — Free

A 24-page printable planner built for Natrona 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.

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 Natrona 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.