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When to Plant Rhubarb in Harrison County, KY

Harrison County, Kentucky Zone 6b May

Harrison County, Kentucky gardeners: here's your May plan

Here's what deserves your attention in Harrison County, Kentucky this month. Everything below is tailored to Zone 6b and timed around your local frost dates.

Avg. last frost April 16
Avg. first frost October 26
Soil temp (4") 58°F
Watering Low
Pest pressure Low
Daylight 14.1 hrs
  1. Transplant rhubarb outside

    Plant tomatoes deep — bury the stem up to the first true leaves to grow extra roots. Everything else goes in at the same depth it grew in the tray.

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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.

Harrison County, Kentucky is in USDA Zone 6b. The average last spring frost is April 16 and the first fall frost is October 26, giving you a growing season of approximately 193 days.

At an elevation of 2,105 feet, Harrison County receives approximately 52.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88°F, providing good warmth for Rhubarb during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Rhubarb root diseases.

Harrison County, KY (Zone 6b) Moderate season
193 days
Last Spring Frost April 16
193 growing days
First Fall Frost October 26

Harrison County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season
Transplant: Apr 30
Recommended (50%) ✓ Fits season
Transplant: May 7
Safe Start (90%) ✓ Fits season
Transplant: May 24

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 Harrison County

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

Soil pH

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

Soil Texture

The silt loam soil in Harrison County 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

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

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.2″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — 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 5.2" 0" ❄️ Dormant
Feb 3.9" 0" ❄️ Dormant
Mar 4.9" 0" ❄️ Dormant
Apr 4.3" 4.3" 0" ✅ Rainfall sufficient
May 4.3" 4" 0.3" 💧 Light watering
Jun 4.3" 4.5" 0" ✅ Rainfall sufficient
Jul 4.3" 4.9" 0" ✅ Rainfall sufficient
Aug 4.3" 5.4" 0" ✅ Rainfall sufficient
Sep 4.3" 3.8" 0.5" 💧 Light watering
Oct 4.3" 3.8" 0.5" 💧 Light watering
Nov 4" 0" ❄️ Dormant
Dec 4.1" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Harrison 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 ~8,760 GDD — county provides 3,088 GDD May not mature

Rhubarb Planting Timeline — Harrison County, KY

Rhubarb Planting Calendar

Activity When Date Range
Transplant Outdoors May 7 May 7 – May 21

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

Month-by-Month Timeline

MonthActivities
January
February
March
April
May Transplant Outdoors
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 6b

📆 Growing Season

193 days in Harrison County

Growing Tips for Rhubarb in Harrison County

Direct sow Rhubarb outdoors after April 16 in Harrison County when soil has warmed and frost danger has passed.

Your 193.0-day growing season in Harrison 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 Harrison County, KY?

Harrison County is in Zone 6b with an average last frost of April 16. Plan your Rhubarb planting based on this frost date — see the calendar above for exact timing.

What planting zone is Harrison County, KY?

Harrison County, Kentucky is in USDA Hardiness Zone 6b. The average last spring frost is April 16 and first fall frost is October 26.

🌱

Your Harrison County Garden Planner — Free

A 24-page printable planner built for Harrison County (Zone 6b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Harrison County, KY. 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.