When to Plant Mustard Greens in Warren County, MO
Top priorities for Warren County, Missouri gardeners in May
May is a pivotal month for Warren County, Missouri gardens. Focus on these tasks first and you'll set up the rest of the season for success.
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Get mustard greens seeds going inside
You're about 24 weeks out from your last frost — the perfect window to get these germinating indoors.
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Collect mustard greens at their peak
This is the payoff month. Bring a basket, bring a friend, and get into the beds.
To set up a strong June, finish these tasks
- 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.
Warren County, Missouri is in USDA Zone 6b. The average last spring frost is April 11 and the first fall frost is October 25, giving you a growing season of approximately 197 days.
At an elevation of 654 feet, Warren County receives approximately 30 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Mustard Greens during the growing season.
Warren County Soil Profile
Soil Type
Silt Loam
Soil pH
5.5-6.5
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 Warren County
How your county's soil matches Mustard Greens's growing requirements.
Soil pH
Your soil pH (5.5–6.5) overlaps with Mustard Greens's range (6.0–7.0), though not a perfect match.
Soil Texture
The silt loam soil in Warren County is excellent for Mustard Greens — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (3.1%). Annual compost additions will help Mustard Greens.
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 Sep 05 to harvest before frost.
For a dedicated fall crop, sow by Aug 16.
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 | — | 1.2" | 0" | ❄️ Dormant |
| Feb | — | 1.5" | 0" | ❄️ Dormant |
| Mar | — | 2.3" | 0" | ❄️ Dormant |
| Apr | 3" | 2.6" | 0.4" | 💧 Light watering |
| May | 3" | 3.2" | 0" | ✅ Rainfall sufficient |
| Jun | 3" | 3.9" | 0" | ✅ Rainfall sufficient |
| Jul | 3" | 3.2" | 0" | ✅ Rainfall sufficient |
| Aug | 3" | 3.6" | 0" | ✅ Rainfall sufficient |
| Sep | 3" | 2.3" | 0.7" | 💧 Light watering |
| Oct | 3" | 2.2" | 0.8" | 💧 Light watering |
| Nov | — | 2.3" | 0" | ❄️ Dormant |
| Dec | — | 1.5" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Warren 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 — Warren County, MO
Mustard Greens Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 7 | Mar 7 – Mar 21 |
| Transplant Outdoors | April 11 | Apr 11 – Apr 25 |
| Direct Sow | March 28 | Mar 28 – Apr 18 |
| Harvest | May 16 | May 16 – Jul 18 |
| Fall Sowing | August 16 | Aug 16 – Aug 30 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors Direct Sow |
| April | Transplant Outdoors Direct Sow |
| May | Harvest |
| June | Harvest |
| July | Harvest |
| August | Fall Sowing |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
0.7"/week · Only during dry spells
📅 Days to Maturity
30–50 days
🧪 Soil pH
Needs 6–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 6b
📆 Growing Season
197 days in Warren County
Growing Tips for Mustard Greens in Warren County
Direct sow Mustard Greens outdoors after April 11 in Warren County when soil has warmed and frost danger has passed.
Your generous 197.0-day season in Warren 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 Warren County, MO?
Warren County is in Zone 6b with an average last frost of April 11. Plan your Mustard Greens planting based on this frost date — see the calendar above for exact timing.
What planting zone is Warren County, MO?
Warren County, Missouri is in USDA Hardiness Zone 6b. The average last spring frost is April 11 and first fall frost is October 25.
Your Warren County Garden Planner — Free
A 24-page printable planner built for Warren County (Zone 6b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.