When to Plant Watercress in St. John the Baptist Parish, LA
Your May planting checklist for St. John the Baptist Parish, Louisiana
Your St. John the Baptist Parish, Louisiana garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.
-
Basket week: watercress
This is the payoff month. Bring a basket, bring a friend, and get into the beds.
Watercress is a semi-aquatic plant with a peppery, tangy flavor rich in vitamins and minerals. It grows naturally along streams and can be cultivated in containers with standing water.
St. John the Baptist Parish, Louisiana is in USDA Zone 9b. The average last spring frost is February 20 and the first fall frost is December 1, giving you a growing season of approximately 284 days.
At an elevation of 309 feet, St. John the Baptist Parish receives approximately 53.7 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 103°F, so Watercress may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Watercress will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Watercress root diseases.
St. John the Baptist Parish Soil Profile
Soil Type
Sandy Loam
Soil pH
4.8-6.1
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. John the Baptist Parish
How your county's soil matches Watercress's growing requirements.
Soil pH
Your soil pH (4.8–6.1) is more acidic than Watercress prefers (6.5–7.5). Add garden lime to raise pH.
Soil Texture
Sandy soil in St. John the Baptist Parish warms quickly in spring but drains fast. Watercress will need more frequent watering and regular compost additions to retain nutrients.
Drainage
Drainage is adequate for Watercress.
Organic Matter
Organic matter is moderate (2.1%). Annual compost additions will help Watercress.
How to Plant Watercress
Fall planting: Sow 8 weeks before your first frost date for a fall harvest.
Succession Planting Watercress
Sow every 4.6 weeks. Last sowing by Oct 02 to harvest before frost.
For a dedicated fall crop, sow by Oct 06.
Plant Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Watercress
Watercress needs approximately 1.5 inches of water per week (6.5" per month). Here's how your county's rainfall compares month by month.
| Month | Watercress Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 4" | 0" | ❄️ Dormant |
| Feb | 6.5" | 4" | 2.5" | 💧 Light watering |
| Mar | 6.5" | 4.6" | 1.9" | 💧 Light watering |
| Apr | 6.5" | 4" | 2.5" | 💧 Light watering |
| May | 6.5" | 4.7" | 1.8" | 💧 Light watering |
| Jun | 6.5" | 5" | 1.5" | 💧 Light watering |
| Jul | 6.5" | 6.3" | 0.2" | 💧 Light watering |
| Aug | 6.5" | 4.7" | 1.8" | 💧 Light watering |
| Sep | 6.5" | 4.3" | 2.2" | 💧 Light watering |
| Oct | 6.5" | 3.7" | 2.8" | 💧 Light watering |
| Nov | 6.5" | 3.5" | 3" | 💧 Light watering |
| Dec | 6.5" | 4.8" | 1.7" | 💧 Light watering |
Water needs are for active growing months only (Feb–Dec in St. John the Baptist Parish). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Watercress 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.
Watercress Planting Timeline — St. John the Baptist Parish, LA
Watercress Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | January 23 | Jan 23 – Feb 6 |
| Transplant Outdoors | February 20 | Feb 20 – Mar 6 |
| Direct Sow | January 30 | Jan 30 – Feb 20 |
| Harvest | April 3 | Apr 3 – May 8 |
| Fall Sowing | October 6 | Oct 6 – Oct 20 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors Direct Sow |
| February | Start Indoors Transplant Outdoors Direct Sow |
| March | Transplant Outdoors |
| April | Harvest |
| May | Harvest |
| June | — |
| July | — |
| August | — |
| September | — |
| October | Fall Sowing |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
1.5"/week · 1-2 times/week
📅 Days to Maturity
40–60 days
🧪 Soil pH
Needs 6.5–7.5 · Your soil: too_acidic
🗺️ USDA Zone
Zone 9b
📆 Growing Season
284 days in St. John the Baptist Parish
Growing Tips for Watercress in St. John the Baptist Parish
Direct sow Watercress outdoors after February 20 in St. John the Baptist Parish when soil has warmed and frost danger has passed.
Sandy soil in St. John the Baptist Parish dries quickly — mulch Watercress with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.
With summer highs reaching 103°F in St. John the Baptist Parish, provide afternoon shade for Watercress and water deeply in the morning.
Your generous 285.0-day season in St. John the Baptist Parish allows multiple plantings of Watercress. Sow every 20.0 days for continuous harvest.
Common pests for Watercress in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.
General growing tips
Grow in containers with trays of water kept fresh. Provide partial shade and cool conditions. Harvest stems by cutting above water level. Replace water frequently to prevent stagnation.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Watercress in Other Locations
Frequently Asked Questions
When should I plant Watercress in St. John the Baptist Parish, LA?
St. John the Baptist Parish is in Zone 9b with an average last frost of February 20. Plan your Watercress planting based on this frost date — see the calendar above for exact timing.
What planting zone is St. John the Baptist Parish, LA?
St. John the Baptist Parish, Louisiana is in USDA Hardiness Zone 9b. The average last spring frost is February 20 and first fall frost is December 1.
Your St. John the Baptist Parish Garden Planner — Free
A 24-page printable planner built for St. John the Baptist 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.