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When to Plant Chervil in Richland County, MT

Richland County, Montana Zone 4a May

This month in Richland County, Montana

Here's what deserves your attention in Richland County, Montana this month. Everything below is tailored to Zone 4a and timed around your local frost dates.

Avg. last frost May 14
Avg. first frost September 20
Soil temp (4") 36°F
Watering High
Pest pressure Low
Daylight 14.9 hrs
  1. Transplant chervil outside

    Pinch off the lowest leaves on each seedling before you plant — it reduces water loss while the roots catch up.

  2. Scatter chervil into prepared beds

    Sow every 2 weeks for a continuous harvest. A single big planting means a single big glut.

A few tasks this May that'll pay off in June
  • Starting indoors: chervil
  • First harvests: chervil
  • Fall sowing: 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.

Richland County, Montana is in USDA Zone 4a. The average last spring frost is May 14 and the first fall frost is September 20, giving you a growing season of approximately 129 days.

At an elevation of 6,414 feet, Richland County receives approximately 13.6 inches of rainfall annually with predominantly loam soil. Summer highs average 80°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.

Richland County, MT (Zone 4a) Short season
129 days
Last Spring Frost May 14
129 growing days
First Fall Frost September 20

Richland County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (31 days to spare)
Start indoors: Mar 29 Transplant: May 3 🍅 Harvest: Jun 14 – Aug 16
Recommended (50%) ✓ Fits season (31 days to spare)
Start indoors: Apr 2 Transplant: May 7 🍅 Harvest: Jun 18 – Aug 20
Safe Start (90%) ✓ Fits season (33 days to spare)
Start indoors: Apr 18 Transplant: May 23 🍅 Harvest: Jul 4 – Sep 5

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 Richland County

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

Soil pH

Your soil pH (6.5–7.8) is more alkaline than Chervil prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.3%). Annual compost additions will help Chervil.

How to Plant Chervil

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

Fall planting: Sow 12 weeks before your first frost date for a fall harvest.

Succession Planting Chervil

3
successive plantings in your 129-day season

Sow every 4.6 weeks. Last sowing by Jul 22 to harvest before frost.

For a dedicated fall crop, sow by Jun 28.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.4″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 79 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 1.2" 0" ❄️ Dormant
Apr 1.4" 0" ❄️ Dormant
May 2.2" 1.6" 0.6" 💧 Light watering
Jun 2.2" 1" 1.2" 🚿 Regular watering
Jul 2.2" 1" 1.2" 🚿 Regular watering
Aug 2.2" 1.6" 0.6" 💧 Light watering
Sep 2.2" 1.1" 1.1" 🚿 Regular watering
Oct 1.2" 0" ❄️ Dormant
Nov 1" 0" ❄️ Dormant
Dec 0.7" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Richland 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 ~500 GDD — county provides 1,290 GDD Excellent fit

Chervil Planting Timeline — Richland County, MT

Chervil Planting Calendar

Activity When Date Range
Start Indoors April 2 Apr 2 – Apr 16
Transplant Outdoors May 7 May 7 – May 21
Direct Sow May 7 May 7 – May 28
Harvest June 18 Jun 18 – Aug 20
Fall Sowing June 28 Jun 28 – Jul 12

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 Fall Sowing 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 4a

📆 Growing Season

129 days in Richland County

Growing Tips for Chervil in Richland County

Direct sow Chervil outdoors after May 14 in Richland 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 Richland County, MT?

Richland County is in Zone 4a with an average last frost of May 14. Plan your Chervil planting based on this frost date — see the calendar above for exact timing.

What planting zone is Richland County, MT?

Richland County, Montana is in USDA Hardiness Zone 4a. The average last spring frost is May 14 and first fall frost is September 20.

🌱

Your Richland County Garden Planner — Free

A 24-page printable planner built for Richland County (Zone 4a). 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 Richland County, MT. 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.