When to Plant Crocus in Jackson County, WI
Top priorities for Jackson County, Wisconsin gardeners in June
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.
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.
Jackson County, Wisconsin is in USDA Zone 4b. The average last spring frost is May 13 and the first fall frost is October 2, giving you a growing season of approximately 142 days.
At an elevation of 608 feet, Jackson County receives approximately 35.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Crocus to ensure they mature before fall.
Jackson County Soil Profile
Soil Type
Silt Loam
Soil pH
6.1-6.7
Drainage
Well Drained
Crocus Planting Risk Windows
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 Jackson County
How your county's soil matches Crocus's growing requirements.
Soil pH
Your soil pH (6.1–6.7) is within Crocus's preferred range (6.0–7.0).
Soil Texture
The silt loam soil in Jackson County is excellent for Crocus — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (5.0%) — Crocus will thrive.
How to Plant Crocus
Fall planting: Sow 6 weeks before your first frost date for a fall harvest.
Succession Planting Crocus
Sow every 1.1 weeks. Last sowing by Sep 12 to harvest before frost.
For a dedicated fall crop, sow by Aug 21.
Crocus Water Budget
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 | — | 1.7" | 0" | ❄️ Dormant |
| Feb | — | 1.5" | 0" | ❄️ Dormant |
| Mar | — | 2.6" | 0" | ❄️ Dormant |
| Apr | — | 3.5" | 0" | ❄️ Dormant |
| May | 2.2" | 3.8" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 4.9" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 3.9" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 3.6" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 3.3" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 2.9" | 0" | ✅ Rainfall sufficient |
| Nov | — | 2.4" | 0" | ❄️ Dormant |
| Dec | — | 1.8" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in Jackson 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 Planting Timeline — Jackson County, WI
Crocus Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Bloom | June 26 | Jun 26 – Jul 24 |
| Fall Sowing | August 21 | Aug 21 – Sep 4 |
Plant 4" deep · 3" apart · Rows 4" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | — |
| June | Bloom |
| July | Bloom |
| August | Fall Sowing |
| September | Fall Sowing |
| October | — |
| 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: ideal
🗺️ USDA Zone
Zone 4b
📆 Growing Season
142 days in Jackson County
Growing Tips for Crocus in Jackson County
Direct sow Crocus outdoors after May 13 in Jackson County when soil has warmed and frost danger has passed.
Your generous 142.0-day season in Jackson 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 →
Crocus in Other Locations
Frequently Asked Questions
When should I plant Crocus in Jackson County, WI?
Jackson County is in Zone 4b with an average last frost of May 13. Plan your Crocus planting based on this frost date — see the calendar above for exact timing.
What planting zone is Jackson County, WI?
Jackson County, Wisconsin is in USDA Hardiness Zone 4b. The average last spring frost is May 13 and first fall frost is October 2.
Your Jackson County Garden Planner — Free
A 22-page printable planner built for Jackson County (Zone 4b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.