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When to Plant Crocus in Gilliam County, OR

Gilliam County, Oregon Zone 7b June

Your June planting checklist for Gilliam County, Oregon

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 April 25
Avg. first frost October 15
Soil temp (4") 71°F
Watering Critical
Pest pressure High
Daylight 15.5 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.

Gilliam County, Oregon is in USDA Zone 7b. The average last spring frost is April 25 and the first fall frost is October 15, giving you a growing season of approximately 173 days.

At an elevation of 965 feet, Gilliam County receives approximately 22.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Crocus during the growing season.

Bulb Blooms in Spring Pollinator-friendly Fragrant
Gilliam County, OR (Zone 7b) Moderate season
173 days
Last Spring Frost April 25
173 growing days
First Fall Frost October 15
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Gilliam County Soil Profile

Soil Type

Silt Loam

Soil pH

5.3-6.7

Drainage

Well Drained

Crocus Planting Risk Windows

Early Start (70% safe) ✓ Fits season (187 days to spare)
Transplant: Apr 15 🌸 Bloom: Mar 11 – Apr 1
Recommended (50%) ✓ Fits season (187 days to spare)
Transplant: Apr 25 🌸 Bloom: Mar 21 – Apr 11
Safe Start (90%) ✓ Fits season (187 days to spare)
Transplant: May 13 🌸 Bloom: Apr 8 – Apr 29

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 Gilliam County

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

Soil pH

Your soil pH (5.3–6.7) overlaps with Crocus's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Crocus.

Organic Matter

Organic matter is excellent (4.5%) — Crocus will thrive.

How to Plant Crocus

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

Fall planting: Sow 5 weeks before your first frost date for a fall harvest.

Succession Planting Crocus

21
successive plantings in your 173-day season

Sow every 1.1 weeks. Last sowing by Sep 25 to harvest before frost.

For a dedicated fall crop, sow by Sep 10.

Crocus Water Budget

Plant needs
0.5″/week
Rainfall provides
0.5″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 163 gal / 100 sq ft

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 2.8" 0" ❄️ Dormant
Feb 2.8" 0" ❄️ Dormant
Mar 2.4" 0" ❄️ Dormant
Apr 2.2" 1.4" 0.8" 💧 Light watering
May 2.2" 1.4" 0.8" 💧 Light watering
Jun 2.2" 0.8" 1.4" 🚿 Regular watering
Jul 2.2" 0.3" 1.9" 🚿 Regular watering
Aug 2.2" 0.5" 1.7" 🚿 Regular watering
Sep 2.2" 0.9" 1.3" 🚿 Regular watering
Oct 2.2" 1.7" 0.5" 💧 Light watering
Nov 3.7" 0" ❄️ Dormant
Dec 3.8" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Gilliam 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 ~206 GDD — county provides 2,378 GDD Excellent fit

Crocus Planting Timeline — Gilliam County, OR

Crocus Planting Calendar

Activity When Date Range
Bloom August 6 Aug 6 – Aug 27
Fall Sowing September 10 Sep 10 – Sep 24

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

Month-by-Month Timeline

MonthActivities
January
February
March
April
May
June
July
August Bloom
September Fall Sowing
October
November
December
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Only during dry spells

📅 Days to Maturity

10–20 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 7b

📆 Growing Season

173 days in Gilliam County

Growing Tips for Crocus in Gilliam County

Direct sow Crocus outdoors after April 25 in Gilliam County when soil has warmed and frost danger has passed.

Your generous 173.0-day season in Gilliam County allows multiple plantings of Crocus. Sow every 5.0 days for continuous harvest.

Gilliam County receives only 22" 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 Gilliam County, OR?

Gilliam County is in Zone 7b with an average last frost of April 25. Plan your Crocus planting based on this frost date — see the calendar above for exact timing.

What planting zone is Gilliam County, OR?

Gilliam County, Oregon is in USDA Hardiness Zone 7b. The average last spring frost is April 25 and first fall frost is October 15.

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Your Gilliam County Garden Planner — Free

A 22-page printable planner built for Gilliam County (Zone 7b). 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 Gilliam County, OR. 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.