When to Plant Cilantro in Weston County, WY
Top priorities for Weston County, Wyoming gardeners in May
May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Weston County, Wyoming.
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Harden off and plant cilantro
Pinch off the lowest leaves on each seedling before you plant — it reduces water loss while the roots catch up.
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Plant cilantro from seed, right in the garden
These tolerate cool soil, so you're not gambling by sowing now.
Get ahead of June
- Starting indoors: cilantro
- First harvests: 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.
Weston County, Wyoming is in USDA Zone 4b. The average last spring frost is May 16 and the first fall frost is September 26, giving you a growing season of approximately 133 days.
At an elevation of 5,889 feet, Weston County receives approximately 20.7 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.
Weston County Soil Profile
Soil Type
Loam
Soil pH
6.7-7.7
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 Weston County
How your county's soil matches Cilantro's growing requirements.
Soil pH
Your soil pH (6.7–7.7) is more alkaline than Cilantro prefers (6.0–7.0). Add sulfur or peat moss to lower pH.
Soil Texture
The loam soil in Weston 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
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 28 to harvest before frost.
For a dedicated fall crop, sow by Jul 04.
Plant Water Budget
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 | — | 1.5" | 0" | ❄️ Dormant |
| Feb | — | 1.4" | 0" | ❄️ Dormant |
| Mar | — | 1.7" | 0" | ❄️ Dormant |
| Apr | — | 2.3" | 0" | ❄️ Dormant |
| May | 2.2" | 2.3" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 1.5" | 0.7" | 💧 Light watering |
| Jul | 2.2" | 1.9" | 0.3" | 💧 Light watering |
| Aug | 2.2" | 2.2" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 1.6" | 0.6" | 💧 Light watering |
| Oct | — | 1.9" | 0" | ❄️ Dormant |
| Nov | — | 1.2" | 0" | ❄️ Dormant |
| Dec | — | 1.1" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in Weston 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 — Weston County, WY
Cilantro Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 4 | Apr 4 – Apr 18 |
| Transplant Outdoors | May 9 | May 9 – May 23 |
| Direct Sow | May 9 | May 9 – May 30 |
| Harvest | June 20 | Jun 20 – Aug 22 |
| Fall Sowing | July 4 | Jul 4 – Jul 18 |
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 | 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
133 days in Weston County
Growing Tips for Cilantro in Weston County
Direct sow Cilantro outdoors after May 16 in Weston 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 Weston County, WY?
Weston County is in Zone 4b with an average last frost of May 16. Plan your Cilantro planting based on this frost date — see the calendar above for exact timing.
What planting zone is Weston County, WY?
Weston County, Wyoming is in USDA Hardiness Zone 4b. The average last spring frost is May 16 and first fall frost is September 26.
Your Weston County Garden Planner — Free
A 24-page printable planner built for Weston 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.