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When to Plant Crocus in Williams County, ND

Williams County, North Dakota Zone 4a June

This month in Williams County, North Dakota

Each item below is timed to Williams County, North Dakota's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost May 14
Avg. first frost September 22
Soil temp (4") 66°F
Watering High
Pest pressure High
Daylight 15.9 hrs

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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.

Williams County, North Dakota is in USDA Zone 4a. The average last spring frost is May 14 and the first fall frost is September 22, giving you a growing season of approximately 131 days.

At an elevation of 947 feet, Williams County receives approximately 28.1 inches of rainfall annually with predominantly loam soil. Summer highs average 84°F, so choose short-season varieties of Crocus to ensure they mature before fall.

Bulb Blooms in Spring Pollinator-friendly Fragrant
Williams County, ND (Zone 4a) Short season
131 days
Last Spring Frost May 14
131 growing days
First Fall Frost September 22
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Williams County Soil Profile

Soil Type

Loam

Soil pH

6.4-7.6

Drainage

Well Drained

Crocus Planting Risk Windows

Early Start (70% safe) ✓ Fits season (166 days to spare)
Transplant: May 10 🌸 Bloom: Mar 15 – Apr 5
Recommended (50%) ✓ Fits season (166 days to spare)
Transplant: May 14 🌸 Bloom: Mar 19 – Apr 9
Safe Start (90%) ✓ Fits season (163 days to spare)
Transplant: May 30 🌸 Bloom: Apr 4 – Apr 25

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 Williams County

How your county's soil matches Crocus's growing requirements.

Soil pH

Your soil pH (6.4–7.6) overlaps with Crocus's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.4%). 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

16
successive plantings in your 131-day season

Sow every 1.1 weeks. Last sowing by Sep 02 to harvest before frost.

For a dedicated fall crop, sow by Aug 11.

Crocus Water Budget

Plant needs
0.5″/week
Rainfall provides
0.9″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 10/10 — 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 1.8" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 2.6" 0" ❄️ Dormant
Apr 3.3" 0" ❄️ Dormant
May 2.2" 3.3" 0" ✅ Rainfall sufficient
Jun 2.2" 2.1" 0.1" 💧 Light watering
Jul 2.2" 2.4" 0" ✅ Rainfall sufficient
Aug 2.2" 2.5" 0" ✅ Rainfall sufficient
Sep 2.2" 2" 0.2" 💧 Light watering
Oct 2.7" 0" ❄️ Dormant
Nov 2.2" 0" ❄️ Dormant
Dec 1.7" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Williams 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 ~195 GDD — county provides 1,703 GDD Excellent fit

Crocus Planting Timeline — Williams County, ND

Crocus Planting Calendar

Activity When Date Range
Bloom June 16 Jun 16 – Jul 7
Fall Sowing August 11 Aug 11 – Aug 25

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
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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: acceptable

🗺️ USDA Zone

Zone 4a

📆 Growing Season

131 days in Williams County

Growing Tips for Crocus in Williams County

Direct sow Crocus outdoors after May 14 in Williams County when soil has warmed and frost danger has passed.

Your generous 131.0-day season in Williams County allows multiple plantings of Crocus. Sow every 5.0 days for continuous harvest.

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 Williams County, ND?

Williams County is in Zone 4a with an average last frost of May 14. Plan your Crocus planting based on this frost date — see the calendar above for exact timing.

What planting zone is Williams County, ND?

Williams County, North Dakota is in USDA Hardiness Zone 4a. The average last spring frost is May 14 and first fall frost is September 22.

🌱

Your Williams County Garden Planner — Free

A 22-page printable planner built for Williams County (Zone 4a). 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 Williams County, ND. 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.