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When to plant Collard Greens in Sanders County County,

For Collard Greens in Sanders County County, the safe spring window opens around May 10 and closes around May 31. Last expected frost is May 24, first fall frost September 13, giving a 112-day growing season. A second sowing from July 5 to July 19 extends the harvest into fall.

When to Plant Collard Greens in Sanders County, MT

Sanders County, Montana Zone 6a June

June in the garden — Sanders County, Montana

If you only do a handful of things in the garden this June, make it these. They're sequenced around your zone's frost timing.

Avg. last frost May 24
Avg. first frost September 13
Soil temp (4") 53°F
Watering High
Pest pressure High
Daylight 15.8 hrs
  1. Time to start collard greens inside

    Give them 6–8 weeks indoors before the last frost and you'll transplant into warm soil with seedlings that are already leaping.

Coming up in July — start thinking about
  • First harvests: collard greens
  • Fall sowing: collard greens

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Collard greens are a heat-tolerant member of the cabbage family with large, sturdy leaves. They are a Southern staple and one of the most nutritious leafy greens.

Sanders County, Montana is in USDA Zone 6a. The average last spring frost is May 24 and the first fall frost is September 13, giving you a growing season of approximately 112 days.

At an elevation of 5,775 feet, Sanders County receives approximately 16.4 inches of rainfall annually with predominantly loam soil. Summer highs average 87°F, providing good warmth for Collard Greens during the growing season. With low rainfall, drip irrigation is essential for growing Collard Greens successfully. Mulch heavily to conserve soil moisture.

Sanders County, MT (Zone 6a) Short season
112 days
Last Spring Frost May 24
112 growing days
First Fall Frost September 13
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Sanders County Soil Profile

Soil Type

Loam

Soil pH

6.3-7.9

Drainage

Well Drained

Collard Greens Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Apr 7 Transplant: May 12 🍅 Harvest: Jul 7 – Sep 8
Recommended (50%) ✗ May not fit
Start indoors: Apr 19 Transplant: May 24 🍅 Harvest: Jul 19 – Sep 20
Safe Start (90%) ✗ May not fit
Start indoors: May 23 Transplant: Jun 27 🍅 Harvest: Aug 22 – Oct 24

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 Sanders County

How your county's soil matches Collard Greens's growing requirements.

Soil pH

Your soil pH (6.3–7.9) is more alkaline than Collard Greens prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Sanders County is excellent for Collard Greens — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.7%). Annual compost additions will help Collard Greens.

How to Plant Collard Greens

1"
Planting Depth
15"
Between Plants
24"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Collard Greens

2
successive plantings in your 112-day season

Sow every 6.3 weeks. Last sowing by Jun 30 to harvest before frost.

For a dedicated fall crop, sow by Jul 05.

Collard Greens Water Budget

Plant needs
0.8″/week
Rainfall provides
0.6″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 221 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Collard Greens

Collard Greens needs approximately 0.8 inches of water per week (3.5" per month). Here's how your county's rainfall compares month by month.

Month Collard Greens Needs Rainfall You Supplement Action
Jan 1.1" 0" ❄️ Dormant
Feb 1" 0" ❄️ Dormant
Mar 1.3" 0" ❄️ Dormant
Apr 1.7" 0" ❄️ Dormant
May 3.5" 1.8" 1.7" 💧 Light watering
Jun 3.5" 1.3" 2.2" 🚿 Regular watering
Jul 3.5" 1.5" 2" 🚿 Regular watering
Aug 3.5" 1.7" 1.8" 🚿 Regular watering
Sep 3.5" 1.4" 2.1" 🚿 Regular watering
Oct 1.4" 0" ❄️ Dormant
Nov 1.2" 0" ❄️ Dormant
Dec 1" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Sanders County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Collard Greens 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.

Collard Greens needs ~991 GDD — county provides 1,708 GDD Excellent fit

Collard Greens Planting Timeline — Sanders County, MT

Collard Greens Planting Calendar

Activity When Date Range
Start Indoors April 19 Apr 19 – May 3
Transplant Outdoors May 24 May 24 – Jun 7
Direct Sow May 10 May 10 – May 31
Harvest July 19 Jul 19 – Sep 20
Fall Sowing July 5 Jul 5 – Jul 19

Plant 1" deep · 15" apart · Rows 24" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April Start Indoors
May Start Indoors Transplant Outdoors Direct Sow
June Transplant Outdoors
July Fall Sowing Harvest
August Harvest
September Harvest
October
November
December
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.8"/week · Only during dry spells

📅 Days to Maturity

55–75 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 6a

📆 Growing Season

112 days in Sanders County

Growing Tips for Collard Greens in Sanders County

Direct sow Collard Greens outdoors after May 24 in Sanders County when soil has warmed and frost danger has passed.

Common pests for Collard Greens in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

Start seeds indoors or direct sow 4-6 weeks before last frost. Harvest lower leaves first, leaving the growing tip intact. Flavor improves after exposure to frost.

Companion Planting

Good Companions

Avoid Planting Near

  • Strawberries
  • Tomatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Collard Greens in Sanders County, MT?

Sanders County is in Zone 6a with an average last frost of May 24. Plan your Collard Greens planting based on this frost date — see the calendar above for exact timing.

What planting zone is Sanders County, MT?

Sanders County, Montana is in USDA Hardiness Zone 6a. The average last spring frost is May 24 and first fall frost is September 13.

When should I plant Collard Greens in Sanders County County, ?

In Sanders County County, , plant Collard Greens after the last frost (around May 24) and before the first frost (around September 13). Best results when soil holds above 50°F.

What growing zone is Sanders County County, for Collard Greens?

Sanders County County sits in USDA Zone 6a. Collard Greens grows reliably in zones 2a through 11b, so it's a good fit here.

Can Collard Greens grow in Sanders County County's climate?

Yes — Collard Greens grows well in Sanders County County's temperate climate. Sanders County County averages a 112-day frost-free season, with last frost around May 24 and first frost around September 13.

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Your Sanders County Garden Planner — Free

A 22-page printable planner built for Sanders County (Zone 6a). 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 Sanders County, MT. Local conditions may vary. Last updated: June 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.