When to Plant Mustard Greens in Jo Daviess County, IL
May to-do list for Jo Daviess County, Illinois
If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.
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Start mustard greens under lights
These need a head start before your last frost (April 24). Sow into cells now so you're ready to transplant in a few weeks.
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It's harvest week for mustard greens
The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.
Before June arrives, get these ready
- First harvests: mustard greens
Mustard greens are fast-growing brassicas with a spicy, peppery kick. They come in green, red, and purple varieties and are excellent cooked or in salads.
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 Mustard Greens during the growing season.
Jo Daviess County Soil Profile
Soil Type
Silt Loam
Soil pH
5.9-7.3
Drainage
Well Drained
Plant 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 Jo Daviess County
How your county's soil matches Mustard Greens's growing requirements.
Soil pH
Your soil pH (5.9–7.3) overlaps with Mustard Greens's range (6.0–7.0), though not a perfect match.
Soil Texture
The silt loam soil in Jo Daviess County is excellent for Mustard Greens — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.2%) — Mustard Greens will thrive.
How to Plant Mustard Greens
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Succession Planting Mustard Greens
Sow every 3.4 weeks. Last sowing by Aug 22 to harvest before frost.
For a dedicated fall crop, sow by Aug 02.
Plant Water Budget
Monthly Watering Guide for Mustard Greens
Mustard Greens needs approximately 0.7 inches of water per week (3" per month). Here's how your county's rainfall compares month by month.
| Month | Mustard Greens Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.3" | 0" | ❄️ Dormant |
| Feb | — | 1.3" | 0" | ❄️ Dormant |
| Mar | — | 2.5" | 0" | ❄️ Dormant |
| Apr | 3" | 3.2" | 0" | ✅ Rainfall sufficient |
| May | 3" | 4.3" | 0" | ✅ Rainfall sufficient |
| Jun | 3" | 4.3" | 0" | ✅ Rainfall sufficient |
| Jul | 3" | 4.2" | 0" | ✅ Rainfall sufficient |
| Aug | 3" | 3.9" | 0" | ✅ Rainfall sufficient |
| Sep | 3" | 3.1" | 0" | ✅ Rainfall sufficient |
| Oct | 3" | 2.8" | 0.2" | 💧 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.
Mustard Greens 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.
Mustard Greens Planting Timeline — Jo Daviess County, IL
Mustard Greens Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 20 | Mar 20 – Apr 3 |
| Transplant Outdoors | April 24 | Apr 24 – May 8 |
| Direct Sow | April 10 | Apr 10 – May 1 |
| Harvest | May 29 | May 29 – Jul 31 |
| Fall Sowing | August 2 | Aug 2 – Aug 16 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Start Indoors Transplant Outdoors Direct Sow |
| May | Transplant Outdoors Direct Sow Harvest |
| June | Harvest |
| July | Harvest |
| August | Fall Sowing |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
0.7"/week · Natural rainfall sufficient
📅 Days to Maturity
30–50 days
🧪 Soil pH
Needs 6–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 5a
📆 Growing Season
170 days in Jo Daviess County
Growing Tips for Mustard Greens in Jo Daviess County
Direct sow Mustard Greens outdoors after April 24 in Jo Daviess County when soil has warmed and frost danger has passed.
Your generous 170.0-day season in Jo Daviess County allows multiple plantings of Mustard Greens. Sow every 15.0 days for continuous harvest.
Common pests for Mustard Greens in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.
General growing tips
Direct sow in early spring or fall. Harvest young leaves for milder flavor. Plants bolt quickly in heat so grow as a cool-season crop or provide shade.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Mustard Greens in Other Locations
Frequently Asked Questions
When should I plant Mustard Greens in Jo Daviess County, IL?
Jo Daviess County is in Zone 5a with an average last frost of April 24. Plan your Mustard Greens 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.
Your Jo Daviess County Garden Planner — Free
A 24-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.