When to Plant Rhubarb in Union Parish, LA
May in Union Parish, Louisiana — your action list
A quick May briefing for Union Parish, Louisiana gardeners — what's urgent, what's next, and what can wait.
Rhubarb is a long-lived perennial vegetable grown for its tart, colorful stalks. Only the stalks are edible as the leaves contain toxic oxalic acid.
Union Parish, Louisiana is in USDA Zone 8b. The average last spring frost is March 22 and the first fall frost is November 5, giving you a growing season of approximately 228 days.
At an elevation of 426 feet, Union Parish receives approximately 57.4 inches of rainfall annually with predominantly loam soil. Summer highs average 96°F, so Rhubarb may need afternoon shade and extra watering during peak heat. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Rhubarb root diseases.
Union Parish Soil Profile
Soil Type
Loam
Soil pH
5.9-7
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 Union Parish
How your county's soil matches Rhubarb's growing requirements.
Soil pH
Your soil pH (5.9–7.0) overlaps with Rhubarb's range (6.0–7.0), though not a perfect match.
Soil Texture
The loam soil in Union Parish is excellent for Rhubarb — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.9%). Annual compost additions will help Rhubarb.
How to Plant Rhubarb
Plant Water Budget
Monthly Watering Guide for Rhubarb
Rhubarb needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Rhubarb Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 4.6" | 0" | ❄️ Dormant |
| Feb | — | 4.7" | 0" | ❄️ Dormant |
| Mar | 4.3" | 4.7" | 0" | ✅ Rainfall sufficient |
| Apr | 4.3" | 4.1" | 0.2" | 💧 Light watering |
| May | 4.3" | 5.2" | 0" | ✅ Rainfall sufficient |
| Jun | 4.3" | 5.3" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 6.1" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 5.4" | 0" | ✅ Rainfall sufficient |
| Sep | 4.3" | 5" | 0" | ✅ Rainfall sufficient |
| Oct | 4.3" | 3.9" | 0.4" | 💧 Light watering |
| Nov | 4.3" | 4.5" | 0" | ✅ Rainfall sufficient |
| Dec | — | 3.9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Mar–Nov in Union Parish). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Rhubarb 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.
Rhubarb Planting Timeline — Union Parish, LA
Rhubarb Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | April 12 | Apr 12 – Apr 26 |
Plant 1" deep · 30" apart · Rows 42" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Transplant Outdoors |
| May | — |
| June | — |
| July | — |
| August | — |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1"/week · Natural rainfall sufficient
📅 Days to Maturity
365–730 days
🧪 Soil pH
Needs 6–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 8b
📆 Growing Season
228 days in Union Parish
Growing Tips for Rhubarb in Union Parish
Direct sow Rhubarb outdoors after March 22 in Union Parish when soil has warmed and frost danger has passed.
With summer highs reaching 96°F in Union Parish, provide afternoon shade for Rhubarb and water deeply in the morning.
Your 228.0-day growing season in Union Parish is tight for Rhubarb (365.0-730.0 days to maturity). Start indoors and choose early-maturing varieties.
General growing tips
Plant crowns in early spring in rich, well-drained soil. Do not harvest stalks the first year. Pull (do not cut) stalks at harvest to avoid introducing rot.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Rhubarb in Other Locations
Frequently Asked Questions
When should I plant Rhubarb in Union Parish, LA?
Union Parish is in Zone 8b with an average last frost of March 22. Plan your Rhubarb planting based on this frost date — see the calendar above for exact timing.
What planting zone is Union Parish, LA?
Union Parish, Louisiana is in USDA Hardiness Zone 8b. The average last spring frost is March 22 and first fall frost is November 5.
Your Union Parish Garden Planner — Free
A 24-page printable planner built for Union Parish (Zone 8b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.