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When to Plant Crocus in Tulsa County, OK

Tulsa County, Oklahoma Zone 7b June

Tulsa County, Oklahoma 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 April 7
Avg. first frost October 26
Soil temp (4") 78°F
Watering Low
Pest pressure High
Daylight 14.4 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.

Tulsa County, Oklahoma is in USDA Zone 7b. The average last spring frost is April 7 and the first fall frost is October 26, giving you a growing season of approximately 202 days.

At an elevation of 752 feet, Tulsa County receives approximately 28.7 inches of rainfall annually with predominantly loam soil. Summer highs average 90°F, providing good warmth for Crocus during the growing season.

Bulb Blooms in Spring Pollinator-friendly Fragrant
Tulsa County, OK (Zone 7b) Long season
202 days
Last Spring Frost April 7
202 growing days
First Fall Frost October 26

Tulsa County Soil Profile

Soil Type

Loam

Soil pH

6.8-7.1

Drainage

Well Drained

Crocus Planting Risk Windows

Early Start (70% safe) ✓ Fits season (214 days to spare)
Transplant: Apr 2 🌸 Bloom: Feb 26 – Mar 19
Recommended (50%) ✓ Fits season (216 days to spare)
Transplant: Apr 7 🌸 Bloom: Mar 3 – Mar 24
Safe Start (90%) ✓ Fits season (216 days to spare)
Transplant: Apr 24 🌸 Bloom: Mar 20 – Apr 10

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 Tulsa County

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

Soil pH

Your soil pH (6.8–7.1) overlaps with Crocus's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.6%). Annual compost additions will help Crocus.

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

25
successive plantings in your 202-day season

Sow every 1.1 weeks. Last sowing by Oct 06 to harvest before frost.

For a dedicated fall crop, sow by Sep 21.

Crocus Water Budget

Plant needs
0.5″/week
Rainfall provides
0.6″/week
Watering frequency Natural rainfall sufficient
Season total 0 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 0.9" 0" ❄️ Dormant
Feb 1.1" 0" ❄️ Dormant
Mar 1.7" 0" ❄️ Dormant
Apr 2.2" 3.5" 0" ✅ Rainfall sufficient
May 2.2" 4.5" 0" ✅ Rainfall sufficient
Jun 2.2" 4.9" 0" ✅ Rainfall sufficient
Jul 2.2" 3.4" 0" ✅ Rainfall sufficient
Aug 2.2" 3" 0" ✅ Rainfall sufficient
Sep 2.2" 2.4" 0" ✅ Rainfall sufficient
Oct 2.2" 1.9" 0.3" 💧 Light watering
Nov 0.9" 0" ❄️ Dormant
Dec 0.7" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Tulsa 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 ~262 GDD — county provides 3,535 GDD Excellent fit

Crocus Planting Timeline — Tulsa County, OK

Crocus Planting Calendar

Activity When Date Range
Bloom August 17 Aug 17 – Sep 7
Fall Sowing September 21 Sep 21 – Oct 5

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 Bloom
October Fall Sowing
November
December

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 7b

📆 Growing Season

202 days in Tulsa County

Growing Tips for Crocus in Tulsa County

Direct sow Crocus outdoors after April 07 in Tulsa County when soil has warmed and frost danger has passed.

Your generous 202.0-day season in Tulsa 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 Tulsa County, OK?

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

What planting zone is Tulsa County, OK?

Tulsa County, Oklahoma is in USDA Hardiness Zone 7b. The average last spring frost is April 7 and first fall frost is October 26.

🌱

Your Tulsa County Garden Planner — Free

A 22-page printable planner built for Tulsa 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.

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 Tulsa County, OK. 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.