Blog

When to plant Crocus in Fallon County County,

Crocus planted in Fallon County County between mid-spring and late spring matures in 20 days — well before the September 20 first frost. A second sowing from August 9 to August 23 extends the harvest into fall.

When to Plant Crocus in Fallon County, MT

Fallon County, Montana Zone 4b June

Fallon County, Montana gardeners: here's your June plan

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 20
Avg. first frost September 20
Soil temp (4") 45°F
Watering High
Pest pressure High
Daylight 15.6 hrs

Instant PDF download. No spam, unsubscribe any time.

Crocuses (Crocus spp.) are the heralds of spring — small, gem-like blooms that push up through frozen ground or even snow, often weeks before any other flower. Their compact corms naturalize readily in lawns, rock gardens, and borders, creating drifts of purple, white, and yellow that expand year after year. Bees prize early crocus as one of their first nectar and pollen sources of the season. The saffron crocus (C. sativus) blooms in fall and yields the world's most expensive spice.

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 Crocus to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Crocus successfully. Mulch heavily to conserve soil moisture.

Bulb Blooms in Spring Pollinator-friendly Fragrant
Fallon County, MT (Zone 4b) Short season
123 days
Last Spring Frost May 20
123 growing days
First Fall Frost September 20
Share this guide:

Fallon County Soil Profile

Soil Type

Loam

Soil pH

6.2-8.3

Drainage

Well Drained

Crocus Planting Risk Windows

Early Start (70% safe) ✓ Fits season (150 days to spare)
Transplant: May 14 🌸 Bloom: Mar 19 – Apr 16
Recommended (50%) ✓ Fits season (151 days to spare)
Transplant: May 20 🌸 Bloom: Mar 25 – Apr 22
Safe Start (90%) ✓ Fits season (146 days to spare)
Transplant: Jun 8 🌸 Bloom: Apr 13 – May 11

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 Crocus's growing requirements.

Soil pH

Your soil pH (6.2–8.3) is more alkaline than Crocus prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.2%). Annual compost additions will help Crocus.

How to Plant Crocus

4"
Planting Depth
3"
Between Plants
4"
Between Rows

Fall planting: Sow 6 weeks before your first frost date for a fall harvest.

Succession Planting Crocus

15
successive plantings in your 123-day season

Sow every 1.1 weeks. Last sowing by Aug 31 to harvest before frost.

For a dedicated fall crop, sow by Aug 09.

Crocus 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 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Crocus

Crocus 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 Crocus 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.

Crocus 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.

Crocus needs ~161 GDD — county provides 1,322 GDD Excellent fit

Crocus Planting Timeline — Fallon County, MT

Crocus Planting Calendar

Activity When Date Range
Bloom June 14 Jun 14 – Jul 12
Fall Sowing August 9 Aug 9 – Aug 23

Plant 4" deep · 3" apart · Rows 4" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April
May
June Bloom
July Bloom
August Fall Sowing
September
October
November
December
Share this guide:

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

10–20 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 4b

📆 Growing Season

123 days in Fallon County

Growing Tips for Crocus in Fallon County

Direct sow Crocus outdoors after May 20 in Fallon County when soil has warmed and frost danger has passed.

Your generous 123.0-day season in Fallon County allows multiple plantings of Crocus. Sow every 5.0 days for continuous harvest.

Fallon County receives only 20" of rain annually. Crocus needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Plant corms 3–4 inches deep and 2–3 inches apart in fall, when soil temperature drops below 60°F. Mass plantings (at least 25 corms per cluster) create the most visual impact. Plant in well-drained soil — corms rot in standing water. Crocus naturalize well under deciduous trees; the tree leafs out after crocus dormancy begins, so light competition is minimal. Squirrels and chipmunks dig corms — plant deeper (4 inches) or use wire mesh baskets in high-predation areas. Allow foliage to die back naturally before mowing lawns. In zones 8a–8b, plant in December with pre-chilled corms for best results.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Crocus in Fallon County, MT?

Fallon County is in Zone 4b with an average last frost of May 20. Plan your Crocus 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.

When should I plant Crocus in Fallon County County, ?

In Fallon County County, , plant Crocus after the last frost (around May 20) and before the first frost (around September 20). Best results when soil holds above 50°F.

What growing zone is Fallon County County, for Crocus?

Fallon County County sits in USDA Zone 4b. Crocus grows reliably in zones 3a through 8b, so it's a good fit here.

Can Crocus grow in Fallon County County's climate?

Yes — Crocus grows well in Fallon County County's temperate climate. Fallon County County averages a 123-day frost-free season, with last frost around May 20 and first frost around September 20.

🌱

Your Fallon County Garden Planner — Free

A 22-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.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Fallon 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.