When to Plant Horseradish in St. Bernard Parish, LA
What to do in May
A quick May briefing for St. Bernard Parish, Louisiana gardeners — what's urgent, what's next, and what can wait.
June prep starts now
- First harvests: horseradish
Horseradish is a vigorous perennial grown for its pungent, spicy roots used as a condiment. Once established, it can be difficult to eradicate, so choose its location carefully.
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 Horseradish may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Horseradish will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Horseradish 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 Horseradish's growing requirements.
Soil pH
Your soil pH (5.2–6.5) is more acidic than Horseradish 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. Horseradish will need more frequent watering and regular compost additions to retain nutrients.
Drainage
Drainage is adequate for Horseradish.
Organic Matter
Organic matter is moderate (2.0%). Annual compost additions will help Horseradish.
How to Plant Horseradish
Plant Water Budget
Monthly Watering Guide for Horseradish
Horseradish needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Horseradish 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.
Horseradish 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.
Horseradish Planting Timeline — St. Bernard Parish, LA
Horseradish Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | February 16 | Feb 16 – Mar 2 |
| Harvest | June 22 | Jun 22 – Aug 31 |
Plant 1" deep · 30" apart · Rows 42" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Transplant Outdoors |
| March | Transplant Outdoors |
| April | — |
| May | — |
| June | Harvest |
| July | Harvest |
| August | Harvest |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1"/week · Only during dry spells
📅 Days to Maturity
120–180 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 Horseradish in St. Bernard Parish
Direct sow Horseradish 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 Horseradish 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 Horseradish and water deeply in the morning.
Common pests for Horseradish in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.
General growing tips
Plant root cuttings at a 45-degree angle in early spring. Harvest roots in late fall for strongest flavor. Contain the plant with barriers or grow in large containers.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Horseradish in Other Locations
Frequently Asked Questions
When should I plant Horseradish in St. Bernard Parish, LA?
St. Bernard Parish is in Zone 9b with an average last frost of February 2. Plan your Horseradish 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.