When to Plant Mizuna in St. Bernard Parish, LA
This month in St. Bernard Parish, Louisiana
Here's what deserves your attention in St. Bernard Parish, Louisiana this month. Everything below is tailored to Zone 9b and timed around your local frost dates.
Mizuna is a mild-flavored Japanese mustard green with feathery, deeply serrated leaves. It is fast-growing and makes an excellent addition to salads and stir-fries.
St. Bernard Parish, Louisiana is in USDA Zone 9b. The average last spring frost is February 2 and the first fall frost is December 11, giving you a growing season of approximately 312 days.
At an elevation of 455 feet, St. Bernard Parish receives approximately 51.7 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 104°F, so Mizuna may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Mizuna will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Mizuna root diseases.
St. Bernard Parish Soil Profile
Soil Type
Sandy Loam
Soil pH
5.2-6.5
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 St. Bernard Parish
How your county's soil matches Mizuna's growing requirements.
Soil pH
Your soil pH (5.2–6.5) is more acidic than Mizuna prefers (6.0–7.5). Add garden lime to raise pH.
Soil Texture
Sandy soil in St. Bernard Parish warms quickly in spring but drains fast. Mizuna will need more frequent watering and regular compost additions to retain nutrients.
Drainage
Drainage is adequate for Mizuna.
Organic Matter
Organic matter is moderate (2.0%). Annual compost additions will help Mizuna.
How to Plant Mizuna
Fall planting: Sow 8 weeks before your first frost date for a fall harvest.
Succession Planting Mizuna
Sow every 3.4 weeks. Last sowing by Oct 27 to harvest before frost.
For a dedicated fall crop, sow by Oct 16.
Plant Water Budget
Monthly Watering Guide for Mizuna
Mizuna needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Mizuna Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 4.6" | 0" | ❄️ Dormant |
| Feb | 4.3" | 4.4" | 0" | ✅ Rainfall sufficient |
| Mar | 4.3" | 5.3" | 0" | ✅ Rainfall sufficient |
| Apr | 4.3" | 4" | 0.3" | 💧 Light watering |
| May | 4.3" | 4.4" | 0" | ✅ Rainfall sufficient |
| Jun | 4.3" | 4.8" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 5.9" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 4.2" | 0.1" | 💧 Light watering |
| Sep | 4.3" | 3.6" | 0.7" | 💧 Light watering |
| Oct | 4.3" | 3.1" | 1.2" | 💧 Light watering |
| Nov | 4.3" | 3.9" | 0.4" | 💧 Light watering |
| Dec | 4.3" | 3.5" | 0.8" | 💧 Light watering |
Water needs are for active growing months only (Feb–Dec in St. Bernard Parish). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Mizuna 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.
Mizuna Planting Timeline — St. Bernard Parish, LA
Mizuna Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | January 5 | Jan 5 – Jan 19 |
| Transplant Outdoors | February 2 | Feb 2 – Feb 16 |
| Direct Sow | January 12 | Jan 12 – Feb 2 |
| Harvest | March 9 | Mar 9 – Apr 6 |
| Fall Sowing | October 16 | Oct 16 – Oct 30 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors Direct Sow |
| February | Transplant Outdoors Direct Sow |
| March | Harvest |
| April | Harvest |
| May | — |
| June | — |
| July | — |
| August | — |
| September | — |
| October | Fall Sowing |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
1"/week · Only during dry spells
📅 Days to Maturity
30–45 days
🧪 Soil pH
Needs 6–7.5 · Your soil: too_acidic
🗺️ USDA Zone
Zone 9b
📆 Growing Season
312 days in St. Bernard Parish
Growing Tips for Mizuna in St. Bernard Parish
Direct sow Mizuna outdoors after February 02 in St. Bernard Parish when soil has warmed and frost danger has passed.
Sandy soil in St. Bernard Parish dries quickly — mulch Mizuna with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.
With summer highs reaching 104°F in St. Bernard Parish, provide afternoon shade for Mizuna and water deeply in the morning.
Your generous 313.0-day season in St. Bernard Parish allows multiple plantings of Mizuna. Sow every 15.0 days for continuous harvest.
Common pests for Mizuna 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 spring or fall. Harvest outer leaves as needed for a cut-and-come-again approach. Mizuna is one of the most cold-tolerant Asian greens.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Mizuna in Other Locations
Frequently Asked Questions
When should I plant Mizuna in St. Bernard Parish, LA?
St. Bernard Parish is in Zone 9b with an average last frost of February 2. Plan your Mizuna planting based on this frost date — see the calendar above for exact timing.
What planting zone is St. Bernard Parish, LA?
St. Bernard Parish, Louisiana is in USDA Hardiness Zone 9b. The average last spring frost is February 2 and first fall frost is December 11.
Your St. Bernard Parish Garden Planner — Free
A 24-page printable planner built for St. Bernard Parish (Zone 9b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.