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When to Plant Cilantro in Pondera County, MT

Pondera County, Montana Zone 4a May

Your May gardening checklist

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

Avg. last frost May 23
Avg. first frost September 16
Soil temp (4") 28°F
Watering High
Pest pressure Low
Daylight 15 hrs
  1. Get cilantro in the ground

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

  2. Sow cilantro where they'll grow

    Keep the top inch of soil moist until germination — a gentle morning watering for 5–7 days does the job.

Get ahead of June
  • First harvests: cilantro
  • Fall sowing: cilantro

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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.

Pondera County, Montana is in USDA Zone 4a. The average last spring frost is May 23 and the first fall frost is September 16, giving you a growing season of approximately 116 days.

At an elevation of 8,118 feet, Pondera County receives approximately 18.4 inches of rainfall annually with predominantly loam soil. Summer highs average 82°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.

Pondera County, MT (Zone 4a) Short season
116 days
Last Spring Frost May 23
116 growing days
First Fall Frost September 16

Pondera County Soil Profile

Soil Type

Loam

Soil pH

6.6-8.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (16 days to spare)
Start indoors: Apr 6 Transplant: May 11 🍅 Harvest: Jun 22 – Aug 24
Recommended (50%) ✓ Fits season (18 days to spare)
Start indoors: Apr 11 Transplant: May 16 🍅 Harvest: Jun 27 – Aug 29
Safe Start (90%) ✓ Fits season (12 days to spare)
Start indoors: Apr 28 Transplant: Jun 2 🍅 Harvest: Jul 14 – Sep 15

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 Pondera County

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

Soil pH

Your soil pH (6.6–8.3) is more alkaline than Cilantro prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

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

How to Plant Cilantro

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 Cilantro

3
successive plantings in your 116-day season

Sow every 4.6 weeks. Last sowing by Jul 18 to harvest before frost.

For a dedicated fall crop, sow by Jun 24.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.7″/week
Watering frequency Natural rainfall sufficient
Season total 0 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 1.3" 0" ❄️ Dormant
Feb 1.1" 0" ❄️ Dormant
Mar 1.7" 0" ❄️ Dormant
Apr 2" 0" ❄️ Dormant
May 2.2" 1.9" 0.3" 💧 Light watering
Jun 2.2" 1.4" 0.8" 💧 Light watering
Jul 2.2" 1.7" 0.5" 💧 Light watering
Aug 2.2" 2" 0.2" 💧 Light watering
Sep 2.2" 1.4" 0.8" 💧 Light watering
Oct 1.7" 0" ❄️ Dormant
Nov 1.3" 0" ❄️ Dormant
Dec 0.9" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Pondera 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 ~575 GDD — county provides 1,334 GDD Excellent fit

Cilantro Planting Timeline — Pondera County, MT

Cilantro Planting Calendar

Activity When Date Range
Start Indoors April 11 Apr 11 – Apr 25
Transplant Outdoors May 16 May 16 – May 30
Direct Sow May 16 May 16 – Jun 6
Harvest June 27 Jun 27 – Aug 29
Fall Sowing June 24 Jun 24 – Jul 8

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 Direct Sow 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 · Natural rainfall sufficient

📅 Days to Maturity

40–60 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 4a

📆 Growing Season

116 days in Pondera County

Growing Tips for Cilantro in Pondera County

Direct sow Cilantro outdoors after May 23 in Pondera 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 Pondera County, MT?

Pondera County is in Zone 4a with an average last frost of May 23. Plan your Cilantro planting based on this frost date — see the calendar above for exact timing.

What planting zone is Pondera County, MT?

Pondera County, Montana is in USDA Hardiness Zone 4a. The average last spring frost is May 23 and first fall frost is September 16.

🌱

Your Pondera County Garden Planner — Free

A 24-page printable planner built for Pondera 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 Pondera 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.