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When to plant Crocus in Jo Daviess County, IL

Plant Crocus in Jo Daviess County from mid-spring to late spring in spring. Jo Daviess County sits in USDA Zone 5a, with last frost around April 24 and first frost on October 11. A second sowing from August 30 to September 13 extends the harvest into fall.

When to Plant Crocus in Jo Daviess County, IL

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.

Jo Daviess County, Illinois is in USDA Zone 5a. The average last spring frost is April 24 and the first fall frost is October 11, giving you a growing season of approximately 170 days.

At an elevation of 501 feet, Jo Daviess County receives approximately 35.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Crocus during the growing season.

Bulb Blooms in Spring Pollinator-friendly Fragrant
Jo Daviess County, IL (Zone 5a) Moderate season
170 days
Last Spring Frost April 24
170 growing days
First Fall Frost October 11

Jo Daviess County Soil Profile

Soil Type

Silt Loam

Soil pH

5.9-7.3

Drainage

Well Drained

Monthly Watering Guide for Crocus

Crocus needs approximately 1 inches of water per week (4.3" 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 2.5" 0" ❄️ Dormant
Apr 4.3" 3.2" 1.1" 💧 Light watering
May 4.3" 4.3" 0" ✅ Rainfall sufficient
Jun 4.3" 4.3" 0" ✅ Rainfall sufficient
Jul 4.3" 4.2" 0.1" 💧 Light watering
Aug 4.3" 3.9" 0.4" 💧 Light watering
Sep 4.3" 3.1" 1.2" 💧 Light watering
Oct 4.3" 2.8" 1.5" 💧 Light watering
Nov 2.2" 0" ❄️ Dormant
Dec 2.2" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Jo Daviess County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Crocus Planting Timeline — Jo Daviess County, IL

Crocus Planting Calendar

Activity When Date Range
Bloom July 12 Jul 12 – Aug 2
Fall Sowing August 30 Aug 30 – Sep 13

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Low — drought tolerant

📅 Days to Maturity

10–20 days

🧪 Soil pH

Needs 6–7 · Your soil: N/A

🗺️ USDA Zone

Zone 5a

📆 Growing Season

170 days in Jo Daviess County

Growing Tips for Jo Daviess County

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 Jo Daviess County, IL?

Jo Daviess County is in Zone 5a with an average last frost of April 24. Plan your Crocus planting based on this frost date — see the calendar above for exact timing.

What planting zone is Jo Daviess County, IL?

Jo Daviess County, Illinois is in USDA Hardiness Zone 5a. The average last spring frost is April 24 and first fall frost is October 11.

When should I plant Crocus in Jo Daviess County, IL?

In Jo Daviess County, IL, plant Crocus after the last frost (around April 24) and before the first frost (around October 11). Best results when soil holds above 50°F.

What growing zone is Jo Daviess County, IL for Crocus?

Jo Daviess County sits in USDA Zone 5a. Crocus grows reliably in zones 3a through 8b, so it's a good fit here.

Can Crocus grow in Jo Daviess County's climate?

Yes — Crocus grows well in Jo Daviess County's temperate climate. Jo Daviess County averages a 170-day frost-free season, with last frost around April 24 and first frost around October 11.

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Your Jo Daviess County Garden Planner — Free

A 22-page printable planner built for Jo Daviess County (Zone 5a). 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 Jo Daviess County, IL. Local conditions may vary. Last updated: July 2026.

Sources & credits

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