When to Plant Rhubarb in Humboldt County, NV
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.
Humboldt County, Nevada is in USDA Zone 5b. The average last spring frost is May 30 and the first fall frost is September 15, giving you a growing season of approximately 108 days.
At an elevation of 5,527 feet, Humboldt County receives approximately 8.2 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 94°F, providing good warmth for Rhubarb during the growing season. Sandy soil warms quickly in spring — great for early planting — but Rhubarb will need more frequent watering and organic matter to retain nutrients. With low rainfall, drip irrigation is essential for growing Rhubarb successfully. Mulch heavily to conserve soil moisture.
Humboldt County Soil Profile
Soil Type
Sandy Loam
Soil pH
7.2-8.6
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 Humboldt County
How your county's soil matches Rhubarb's growing requirements.
Soil pH
Your soil pH (7.2–8.6) is more alkaline than Rhubarb prefers (6.0–7.0). Add sulfur or peat moss to lower pH.
Soil Texture
Sandy soil in Humboldt County warms quickly in spring but drains fast. Rhubarb will need more frequent watering and regular compost additions to retain nutrients.
Drainage
Drainage is adequate for Rhubarb.
Organic Matter
Organic matter is low (0.9%). Add 2-3 inches of compost before planting Rhubarb.
How to Plant Rhubarb
Plant Water Budget
Water stress score is 10/10 — consider drought-tolerant varieties and mulching
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 | — | 0.6" | 0" | ❄️ Dormant |
| Feb | — | 0.5" | 0" | ❄️ Dormant |
| Mar | — | 0.4" | 0" | ❄️ Dormant |
| Apr | — | 0.3" | 0" | ❄️ Dormant |
| May | 4.3" | 0.2" | 4.1" | 🚿 Regular watering |
| Jun | 4.3" | 0.3" | 4" | 🚿 Regular watering |
| Jul | 4.3" | 1.3" | 3" | 🚿 Regular watering |
| Aug | 4.3" | 1.6" | 2.7" | 🚿 Regular watering |
| Sep | 4.3" | 1.1" | 3.2" | 🚿 Regular watering |
| Oct | — | 0.8" | 0" | ❄️ Dormant |
| Nov | — | 0.4" | 0" | ❄️ Dormant |
| Dec | — | 0.6" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in Humboldt County). 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 — Humboldt County, NV
Rhubarb Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | June 20 | Jun 20 – Jul 4 |
Plant 1" deep · 30" apart · Rows 42" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | — |
| June | Transplant Outdoors |
| July | Transplant Outdoors |
| August | — |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1"/week · 2-3 times/week
📅 Days to Maturity
365–730 days
🧪 Soil pH
Needs 6–7 · Your soil: too_alkaline
🗺️ USDA Zone
Zone 5b
📆 Growing Season
108 days in Humboldt County
Growing Tips for Rhubarb in Humboldt County
Direct sow Rhubarb outdoors after May 30 in Humboldt County when soil has warmed and frost danger has passed.
Sandy soil in Humboldt County dries quickly — mulch Rhubarb with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.
Your 108.0-day growing season in Humboldt County is tight for Rhubarb (365.0-730.0 days to maturity). Start indoors and choose early-maturing varieties.
Humboldt County receives only 8" of rain annually. Rhubarb needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.
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 Humboldt County, NV?
Humboldt County is in Zone 5b with an average last frost of May 30. Plan your Rhubarb planting based on this frost date — see the calendar above for exact timing.
What planting zone is Humboldt County, NV?
Humboldt County, Nevada is in USDA Hardiness Zone 5b. The average last spring frost is May 30 and first fall frost is September 15.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Humboldt County gardeners in Zone 5b organize planting dates, track what's growing, and never miss a planting window.
Get Your Free Garden Planner →Free download. Plan your entire garden season in minutes.