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When to Plant Rhubarb in Lake of the Woods County, MN

Lake of the Woods County, Minnesota Zone 3b May

May in the garden — Lake of the Woods County, Minnesota

We've pulled the most time-sensitive tasks for Lake of the Woods County, Minnesota this May and put them front and centre. Tackle them in order.

Avg. last frost May 19
Avg. first frost September 22
Soil temp (4") 52°F
Watering Low
Pest pressure Low
Daylight 15 hrs
Looking ahead to June
  • Transplants going out: rhubarb

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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.

Lake of the Woods County, Minnesota is in USDA Zone 3b. The average last spring frost is May 19 and the first fall frost is September 22, giving you a growing season of approximately 126 days.

At an elevation of 1,032 feet, Lake of the Woods County receives approximately 32.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80°F, so choose short-season varieties of Rhubarb to ensure they mature before fall.

Lake of the Woods County, MN (Zone 3b) Short season
126 days
Last Spring Frost May 19
126 growing days
First Fall Frost September 22

Lake of the Woods County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season
Transplant: Jun 11
Recommended (50%) ✓ Fits season
Transplant: Jun 16
Safe Start (90%) ✓ Fits season
Transplant: Jul 1

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 Lake of the Woods County

How your county's soil matches Rhubarb's growing requirements.

Soil pH

Your soil pH (5.7–7.2) overlaps with Rhubarb's range (6.0–7.0), though not a perfect match.

Soil Texture

The silt loam soil in Lake of the Woods County is excellent for Rhubarb — good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Rhubarb.

Organic Matter

Organic matter is excellent (5.0%) — Rhubarb will thrive.

How to Plant Rhubarb

1"
Planting Depth
30"
Between Plants
42"
Between Rows

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.1″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 228 gal / 100 sq ft

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 1.2" 0" ❄️ Dormant
Feb 1.6" 0" ❄️ Dormant
Mar 2.5" 0" ❄️ Dormant
Apr 2.8" 0" ❄️ Dormant
May 4.3" 4.4" 0" ✅ Rainfall sufficient
Jun 4.3" 4" 0.3" 💧 Light watering
Jul 4.3" 3.6" 0.7" 💧 Light watering
Aug 4.3" 3.3" 1" 💧 Light watering
Sep 4.3" 3" 1.3" 💧 Light watering
Oct 2.2" 0" ❄️ Dormant
Nov 2.6" 0" ❄️ Dormant
Dec 1.8" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Lake of the Woods 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 needs ~5,475 GDD — county provides 1,260 GDD May not mature

Rhubarb Planting Timeline — Lake of the Woods County, MN

Rhubarb Planting Calendar

Activity When Date Range
Transplant Outdoors June 16 Jun 16 – Jun 30

Plant 1" deep · 30" apart · Rows 42" apart

Month-by-Month Timeline

MonthActivities
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 · Only during dry spells

📅 Days to Maturity

365–730 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 3b

📆 Growing Season

126 days in Lake of the Woods County

Growing Tips for Rhubarb in Lake of the Woods County

Direct sow Rhubarb outdoors after May 19 in Lake of the Woods County when soil has warmed and frost danger has passed.

Your 126.0-day growing season in Lake of the Woods County 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 →

Frequently Asked Questions

When should I plant Rhubarb in Lake of the Woods County, MN?

Lake of the Woods County is in Zone 3b with an average last frost of May 19. Plan your Rhubarb planting based on this frost date — see the calendar above for exact timing.

What planting zone is Lake of the Woods County, MN?

Lake of the Woods County, Minnesota is in USDA Hardiness Zone 3b. The average last spring frost is May 19 and first fall frost is September 22.

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Your Lake of the Woods County Garden Planner — Free

A 24-page printable planner built for Lake of the Woods County (Zone 3b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Lake of the Woods County, MN. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.