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When to Plant Crocus in Sherman County, OR

Sherman County, Oregon Zone 7a June

Top priorities for Sherman County, Oregon gardeners in June

Your garden in Sherman County, Oregon is working on a schedule, even when you're not. Here's where you should be this June.

Avg. last frost April 14
Avg. first frost October 17
Soil temp (4") 72°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.

Sherman County, Oregon is in USDA Zone 7a. The average last spring frost is April 14 and the first fall frost is October 17, giving you a growing season of approximately 186 days.

At an elevation of 862 feet, Sherman County receives approximately 15 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Crocus during the growing season. With low rainfall, drip irrigation is essential for growing Crocus successfully. Mulch heavily to conserve soil moisture.

Bulb Blooms in Spring Pollinator-friendly Fragrant
Sherman County, OR (Zone 7a) Moderate season
186 days
Last Spring Frost April 14
186 growing days
First Fall Frost October 17

Sherman County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-6.3

Drainage

Well Drained

Crocus Planting Risk Windows

Early Start (70% safe) ✓ Fits season (201 days to spare)
Transplant: Apr 7 🌸 Bloom: Mar 3 – Mar 24
Recommended (50%) ✓ Fits season (200 days to spare)
Transplant: Apr 14 🌸 Bloom: Mar 10 – Mar 31
Safe Start (90%) ✓ Fits season (198 days to spare)
Transplant: May 2 🌸 Bloom: Mar 28 – Apr 18

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 Sherman County

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

Soil pH

Your soil pH (5.7–6.3) overlaps with Crocus's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.9%) — 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

23
successive plantings in your 186-day season

Sow every 1.1 weeks. Last sowing by Sep 27 to harvest before frost.

For a dedicated fall crop, sow by Sep 12.

Crocus Water Budget

Plant needs
0.5″/week
Rainfall provides
0.3″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 267 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 2.2" 0" ❄️ Dormant
Feb 1.6" 0" ❄️ Dormant
Mar 1.5" 0" ❄️ Dormant
Apr 2.2" 1.2" 1" 💧 Light watering
May 2.2" 0.8" 1.4" 🚿 Regular watering
Jun 2.2" 0.5" 1.7" 🚿 Regular watering
Jul 2.2" 0.2" 2" 🚿 Regular watering
Aug 2.2" 0.3" 1.9" 🚿 Regular watering
Sep 2.2" 0.5" 1.7" 🚿 Regular watering
Oct 2.2" 1.3" 0.9" 💧 Light watering
Nov 2.4" 0" ❄️ Dormant
Dec 2.4" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Sherman 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 ~251 GDD — county provides 3,115 GDD Excellent fit

Crocus Planting Timeline — Sherman County, OR

Crocus Planting Calendar

Activity When Date Range
Bloom August 8 Aug 8 – Aug 29
Fall Sowing September 12 Sep 12 – Sep 26

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

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 7a

📆 Growing Season

186 days in Sherman County

Growing Tips for Crocus in Sherman County

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

Your generous 186.0-day season in Sherman County allows multiple plantings of Crocus. Sow every 5.0 days for continuous harvest.

Sherman County receives only 15" 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 Sherman County, OR?

Sherman County is in Zone 7a with an average last frost of April 14. Plan your Crocus planting based on this frost date — see the calendar above for exact timing.

What planting zone is Sherman County, OR?

Sherman County, Oregon is in USDA Hardiness Zone 7a. The average last spring frost is April 14 and first fall frost is October 17.

🌱

Your Sherman County Garden Planner — Free

A 22-page printable planner built for Sherman County (Zone 7a). 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 Sherman 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.