When to Plant Cilantro in Fallon County, MT
Top priorities for Fallon County, Montana gardeners in May
Your Fallon County, Montana garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.
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Move cilantro into the garden
Bring a watering can to the bed. Each transplant gets a drink the moment it's in the ground, not ten minutes later.
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Seed cilantro outdoors
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
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.
Fallon County, Montana is in USDA Zone 4b. The average last spring frost is May 20 and the first fall frost is September 20, giving you a growing season of approximately 123 days.
At an elevation of 6,441 feet, Fallon County receives approximately 19.8 inches of rainfall annually with predominantly loam soil. Summer highs average 81°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.
Fallon County Soil Profile
Soil Type
Loam
Soil pH
6.2-8.3
Drainage
Well Drained
Plant Planting Risk Windows
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 Fallon County
How your county's soil matches Cilantro's growing requirements.
Soil pH
Your soil pH (6.2–8.3) is more alkaline than Cilantro prefers (6.0–7.0). Add sulfur or peat moss to lower pH.
Soil Texture
The loam soil in Fallon County is excellent for Cilantro — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.2%). Annual compost additions will help Cilantro.
How to Plant Cilantro
Fall planting: Sow 12 weeks before your first frost date for a fall harvest.
Succession Planting Cilantro
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
Water stress score is 6/10 — 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 | — | 1.3" | 0" | ❄️ Dormant |
| Mar | — | 1.8" | 0" | ❄️ Dormant |
| Apr | — | 2.1" | 0" | ❄️ Dormant |
| May | 2.2" | 2.7" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 1.4" | 0.8" | 💧 Light watering |
| Jul | 2.2" | 1.6" | 0.6" | 💧 Light watering |
| Aug | 2.2" | 1.9" | 0.3" | 💧 Light watering |
| Sep | 2.2" | 1.6" | 0.6" | 💧 Light watering |
| Oct | — | 1.7" | 0" | ❄️ Dormant |
| Nov | — | 1.2" | 0" | ❄️ Dormant |
| Dec | — | 1.2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in Fallon 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 Planting Timeline — Fallon County, MT
Cilantro Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 8 | Apr 8 – Apr 22 |
| Transplant Outdoors | May 13 | May 13 – May 27 |
| Direct Sow | May 13 | May 13 – Jun 3 |
| Harvest | June 24 | Jun 24 – Aug 26 |
| Fall Sowing | June 28 | Jun 28 – Jul 12 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| 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 4b
📆 Growing Season
123 days in Fallon County
Growing Tips for Cilantro in Fallon County
Direct sow Cilantro outdoors after May 20 in Fallon 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
Check more plant combinations with our Companion Planting Checker →
Cilantro in Other Locations
Frequently Asked Questions
When should I plant Cilantro in Fallon County, MT?
Fallon County is in Zone 4b with an average last frost of May 20. Plan your Cilantro planting based on this frost date — see the calendar above for exact timing.
What planting zone is Fallon County, MT?
Fallon County, Montana is in USDA Hardiness Zone 4b. The average last spring frost is May 20 and first fall frost is September 20.
Your Fallon County Garden Planner — Free
A 24-page printable planner built for Fallon County (Zone 4b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.