When to Plant Sunchoke in St. Mary Parish, LA
May to-do list for St. Mary Parish, Louisiana
Each item below is timed to St. Mary Parish, Louisiana's frost dates and soil temperatures. Skip nothing, stress about nothing.
Get ahead of June
- First harvests: sunchoke
Sunchokes (Jerusalem artichokes) are a native sunflower relative grown for their knobby, nutty-flavored tubers. They are extremely productive and nearly impossible to eradicate.
St. Mary Parish, Louisiana is in USDA Zone 9b. The average last spring frost is February 14 and the first fall frost is December 5, giving you a growing season of approximately 294 days.
At an elevation of 252 feet, St. Mary Parish receives approximately 48.5 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 95°F, so Sunchoke may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Sunchoke will need more frequent watering and organic matter to retain nutrients.
St. Mary Parish Soil Profile
Soil Type
Sandy Loam
Soil pH
4.8-6.4
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. Mary Parish
How your county's soil matches Sunchoke's growing requirements.
Soil pH
Your soil pH (4.8–6.4) is more acidic than Sunchoke prefers (6.0–7.5). Add garden lime to raise pH.
Soil Texture
Sandy soil in St. Mary Parish warms quickly in spring but drains fast. Sunchoke will need more frequent watering and regular compost additions to retain nutrients.
Drainage
Drainage is adequate for Sunchoke.
Organic Matter
Organic matter is moderate (2.0%). Annual compost additions will help Sunchoke.
How to Plant Sunchoke
Plant Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Sunchoke
Sunchoke needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Sunchoke Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 3.6" | 0" | ❄️ Dormant |
| Feb | 4.3" | 3.4" | 0.9" | 💧 Light watering |
| Mar | 4.3" | 5.1" | 0" | ✅ Rainfall sufficient |
| Apr | 4.3" | 3.8" | 0.5" | 💧 Light watering |
| May | 4.3" | 3.8" | 0.5" | 💧 Light watering |
| Jun | 4.3" | 3.6" | 0.7" | 💧 Light watering |
| Jul | 4.3" | 5.6" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 5.1" | 0" | ✅ Rainfall sufficient |
| Sep | 4.3" | 3.5" | 0.8" | 💧 Light watering |
| Oct | 4.3" | 3.1" | 1.2" | 💧 Light watering |
| Nov | 4.3" | 3.9" | 0.4" | 💧 Light watering |
| Dec | 4.3" | 4.2" | 0.1" | 💧 Light watering |
Water needs are for active growing months only (Feb–Dec in St. Mary Parish). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Sunchoke 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.
Sunchoke Planting Timeline — St. Mary Parish, LA
Sunchoke Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | February 28 | Feb 28 – Mar 14 |
| Harvest | June 20 | Jun 20 – Aug 15 |
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
110–150 days
🧪 Soil pH
Needs 6–7.5 · Your soil: too_acidic
🗺️ USDA Zone
Zone 9b
📆 Growing Season
294 days in St. Mary Parish
Growing Tips for Sunchoke in St. Mary Parish
Direct sow Sunchoke outdoors after February 14 in St. Mary Parish when soil has warmed and frost danger has passed.
Sandy soil in St. Mary Parish dries quickly — mulch Sunchoke with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.
Common pests for Sunchoke in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.
General growing tips
Plant tubers 4 inches deep in early spring. Contain plants with barriers as they spread aggressively. Harvest after frost or leave in ground and dig as needed through winter.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Sunchoke in Other Locations
Frequently Asked Questions
When should I plant Sunchoke in St. Mary Parish, LA?
St. Mary Parish is in Zone 9b with an average last frost of February 14. Plan your Sunchoke planting based on this frost date — see the calendar above for exact timing.
What planting zone is St. Mary Parish, LA?
St. Mary Parish, Louisiana is in USDA Hardiness Zone 9b. The average last spring frost is February 14 and first fall frost is December 5.
Your St. Mary Parish Garden Planner — Free
A 24-page printable planner built for St. Mary 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.