When to Plant Rhubarb in Palmer, AK
May in the garden — Palmer, Alaska
Each item below is timed to Palmer, Alaska's frost dates and soil temperatures. Skip nothing, stress about nothing.
Get ahead of June
- Transplants going out: rhubarb
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.
Palmer, Alaska is in USDA Zone 4b. The average last spring frost is May 17 and the first fall frost is September 18, giving you a growing season of approximately 124 days.
At an elevation of 1,177 feet, Palmer receives approximately 52.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 69°F, so choose short-season varieties of Rhubarb to ensure they mature before fall. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Rhubarb root diseases.
Palmer Soil Profile
Soil Type
Silt Loam
Soil pH
4.9-6.7
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 Palmer
How your county's soil matches Rhubarb's growing requirements.
Soil pH
Your soil pH (4.9–6.7) is more acidic than Rhubarb prefers (6.0–7.0). Add garden lime to raise pH.
Soil Texture
The silt loam soil in Palmer is excellent for Rhubarb — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Rhubarb.
Organic Matter
Organic matter is excellent (6.8%) — Rhubarb will thrive.
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 | — | 2.5" | 0" | ❄️ Dormant |
| Feb | — | 2.5" | 0" | ❄️ Dormant |
| Mar | — | 2.2" | 0" | ❄️ Dormant |
| Apr | — | 1.6" | 0" | ❄️ Dormant |
| May | 4.3" | 2.2" | 2.1" | 💧 Light watering |
| Jun | 4.3" | 4.3" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 7.4" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 7.7" | 0" | ✅ Rainfall sufficient |
| Sep | 4.3" | 8.3" | 0" | ✅ Rainfall sufficient |
| Oct | — | 6.5" | 0" | ❄️ Dormant |
| Nov | — | 3.9" | 0" | ❄️ Dormant |
| Dec | — | 3.3" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in Palmer). 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 — Palmer, AK
Rhubarb Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | June 14 | Jun 14 – Jun 28 |
Plant 1" deep · 30" apart · Rows 42" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | — |
| June | Transplant Outdoors |
| 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: too_acidic
🗺️ USDA Zone
Zone 4b
📆 Growing Season
124 days in Palmer
Growing Tips for Rhubarb in Palmer
Direct sow Rhubarb outdoors after May 17 in Palmer when soil has warmed and frost danger has passed.
Your 124.0-day growing season in Palmer 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 Palmer, AK?
Palmer is in Zone 4b with an average last frost of May 17. Plan your Rhubarb planting based on this frost date — see the calendar above for exact timing.
What planting zone is Palmer, AK?
Palmer, Alaska is in USDA Hardiness Zone 4b. The average last spring frost is May 17 and first fall frost is September 18.
Your Palmer Garden Planner — Free
A 24-page printable planner built for Palmer (Zone 4b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.