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When to Plant Chervil in Natrona County, WY

Natrona County, Wyoming Zone 5a May

Natrona County, Wyoming gardeners: here's your May plan

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 chervil from tray to bed

    Frost risk is low now in Natrona County, Wyoming. If you've been covering beds overnight, you can stop.

  2. Seed chervil outdoors

    Your soil is 38°F — warm enough for these to germinate without babying.

June will be here before you know it — start on
  • Starting indoors: chervil
  • First harvests: chervil

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Chervil is a delicate herb with a subtle anise-parsley flavor, essential in French cuisine as part of fines herbes. It prefers cool conditions and partial shade.

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 Chervil to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Chervil 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

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 Chervil's growing requirements.

Soil pH

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

Soil Texture

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

Organic Matter

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

How to Plant Chervil

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 Chervil

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 Chervil

Chervil 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 Chervil 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.

Chervil 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.

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

Chervil Planting Timeline — Natrona County, WY

Chervil 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

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 Chervil in Natrona County

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

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

General growing tips

Direct sow in early spring or fall as chervil bolts in heat. Provide shade and cool conditions. Harvest outer leaves as needed; use fresh as it loses flavor when dried.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Chervil in Natrona County, WY?

Natrona County is in Zone 5a with an average last frost of May 19. Plan your Chervil 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.

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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 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.