When to Plant Peas in Gallatin County, MT
Gallatin County, Montana gardeners: here's your May plan
Welcome to May in Zone 5a. These are the moves that will have the biggest impact on your growing season.
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Plant peas from seed, right in the garden
Rake a smooth bed, make a shallow furrow, drop seeds at the spacing on the packet, water gently, walk away.
June will be here before you know it — start on
- Transplants going out: peas
Peas are a cool-season legume that fixes nitrogen in the soil. Garden peas are shelled, while snap and snow peas are eaten pod and all.
Gallatin County, Montana is in USDA Zone 5a. The average last spring frost is June 8 and the first fall frost is September 19, giving you a growing season of approximately 103 days.
At an elevation of 8,376 feet, Gallatin County receives approximately 12.4 inches of rainfall annually with predominantly loam soil. Summer highs average 82°F, so choose short-season varieties of Peas to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Peas successfully. Mulch heavily to conserve soil moisture.
Gallatin County Soil Profile
Soil Type
Loam
Soil pH
6.2-8.1
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 Gallatin County
How your county's soil matches Peas's growing requirements.
Soil pH
Your soil pH (6.2–8.1) overlaps with Peas's range (6.0–7.5), though not a perfect match.
Soil Texture
The loam soil in Gallatin County is excellent for Peas — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.4%). Annual compost additions will help Peas.
How to Plant Peas
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Succession Planting Peas
Sow every 6.3 weeks. Last sowing by Jul 11 to harvest before frost.
For a dedicated fall crop, sow by Jul 11.
Plant Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Peas
Peas needs approximately 0.7 inches of water per week (3" per month). Here's how your county's rainfall compares month by month.
| Month | Peas Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 0.8" | 0" | ❄️ Dormant |
| Feb | — | 0.8" | 0" | ❄️ Dormant |
| Mar | — | 1.1" | 0" | ❄️ Dormant |
| Apr | — | 1.3" | 0" | ❄️ Dormant |
| May | — | 1.3" | 0" | ❄️ Dormant |
| Jun | 3" | 0.8" | 2.2" | 🚿 Regular watering |
| Jul | 3" | 1" | 2" | 🚿 Regular watering |
| Aug | 3" | 1.5" | 1.5" | 🚿 Regular watering |
| Sep | 3" | 1" | 2" | 🚿 Regular watering |
| Oct | — | 1.1" | 0" | ❄️ Dormant |
| Nov | — | 1" | 0" | ❄️ Dormant |
| Dec | — | 0.8" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Jun–Sep in Gallatin County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Peas 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.
Peas Planting Timeline — Gallatin County, MT
Peas Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | May 4 | May 4 – May 18 |
| Transplant Outdoors | June 8 | Jun 8 – Jun 22 |
| Direct Sow | May 25 | May 25 – Jun 15 |
| Harvest | August 3 | Aug 3 – Sep 28 |
| Fall Sowing | July 11 | Jul 11 – Jul 25 |
Plant 1" deep · 4" apart · Rows 18" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | Start Indoors Direct Sow |
| June | Transplant Outdoors Direct Sow |
| July | Fall Sowing |
| August | Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.7"/week · Only during dry spells
📅 Days to Maturity
55–70 days
🧪 Soil pH
Needs 6–7.5 · Your soil: acceptable
🗺️ USDA Zone
Zone 5a
📆 Growing Season
103 days in Gallatin County
Growing Tips for Peas in Gallatin County
Direct sow Peas outdoors after June 08 in Gallatin County when soil has warmed and frost danger has passed.
Common pests for Peas in this region include bean beetles and aphids. Use row covers early in the season and inspect plants weekly.
General growing tips
Direct sow as early as soil can be worked in spring. Inoculate seeds with rhizobium for best nitrogen fixation. Provide trellising for climbing varieties.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Very easy to save. Self-pollinating means varieties stay true.
Peas in Other Locations
Frequently Asked Questions
When should I plant Peas in Gallatin County, MT?
Gallatin County is in Zone 5a with an average last frost of June 8. Plan your Peas planting based on this frost date — see the calendar above for exact timing.
What planting zone is Gallatin County, MT?
Gallatin County, Montana is in USDA Hardiness Zone 5a. The average last spring frost is June 8 and first fall frost is September 19.
Your Gallatin County Garden Planner — Free
A 24-page printable planner built for Gallatin 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.