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When to Plant Cranberries in Rockcastle County, KY

Rockcastle County, Kentucky Zone 7a April

Your April gardening checklist

Welcome to April in Zone 7a. These are the moves that will have the biggest impact on your growing season.

Avg. last frost April 16
Avg. first frost October 23
Soil temp (4") 50°F
Watering Moderate
Pest pressure Low
Daylight 13 hrs
May will be here before you know it — start on
  • Transplants going out: cranberries

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Cranberries are low-growing, vine-like shrubs that produce tart red berries in fall. They grow in acidic, boggy conditions and are surprisingly easy to cultivate.

Rockcastle County, Kentucky is in USDA Zone 6b. The average last spring frost is April 16 and the first fall frost is October 23, giving you a growing season of approximately 190 days.

At an elevation of 1,677 feet, Rockcastle County receives approximately 41.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 91°F, providing good warmth for Cranberries during the growing season.

Rockcastle County, KY (Zone 6b) Moderate season
190 days
Last Spring Frost April 16
190 growing days
First Fall Frost October 23
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Rockcastle County Soil Profile

Soil Type

Silt Loam

Soil pH

5.3-6.9

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season
Transplant: Apr 29
Recommended (50%) ✓ Fits season
Transplant: May 7
Safe Start (90%) ✓ Fits season
Transplant: May 22

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 Rockcastle County

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

Soil pH

Your soil pH (5.3–6.9) is more alkaline than Cranberries prefers (4.0–5.5). Add sulfur or peat moss to lower pH.

Soil Texture

The silt loam soil in Rockcastle County is excellent for Cranberries — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.9%). Annual compost additions will help Cranberries.

How to Plant Cranberries

36"
Between Plants
48"
Between Rows

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.9″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 989 gal / 100 sq ft

Monthly Watering Guide for Cranberries

Cranberries needs approximately 1.5 inches of water per week (6.5" per month). Here's how your county's rainfall compares month by month.

Month Cranberries Needs Rainfall You Supplement Action
Jan 3.1" 0" ❄️ Dormant
Feb 3.6" 0" ❄️ Dormant
Mar 4.1" 0" ❄️ Dormant
Apr 6.5" 3.4" 3.1" 💧 Light watering
May 6.5" 3" 3.5" 🚿 Regular watering
Jun 6.5" 3.5" 3" 💧 Light watering
Jul 6.5" 3.9" 2.6" 💧 Light watering
Aug 6.5" 3.8" 2.7" 💧 Light watering
Sep 6.5" 3.2" 3.3" 🚿 Regular watering
Oct 6.5" 3.1" 3.4" 🚿 Regular watering
Nov 3.3" 0" ❄️ Dormant
Dec 3.3" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Rockcastle County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Cranberries 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.

Cranberries needs ~16,653 GDD — county provides 3,467 GDD May not mature

Cranberries Planting Timeline — Rockcastle County, KY

Cranberries Planting Calendar

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

· 36" apart · Rows 48" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April
May Transplant Outdoors
June
July
August
September
October
November
December
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.5"/week · 1-2 times/week

📅 Days to Maturity

730–1095 days

🧪 Soil pH

Needs 4–5.5 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 6b

📆 Growing Season

190 days in Rockcastle County

Growing Tips for Cranberries in Rockcastle County

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

Your 190.0-day growing season in Rockcastle County is tight for Cranberries (730.0-1095.0 days to maturity). Start indoors and choose early-maturing varieties.

General growing tips

Create an acidic, consistently moist bed with peat moss. Cranberries do not need to be flooded to grow; flooding is only used for commercial harvesting. Mulch with sand in early spring.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Cranberries in Rockcastle County, KY?

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

What planting zone is Rockcastle County, KY?

Rockcastle County, Kentucky is in USDA Hardiness Zone 6b. The average last spring frost is April 16 and first fall frost is October 23.

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Your Rockcastle County Garden Planner — Free

A 24-page printable planner built for Rockcastle 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.

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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 Rockcastle County, KY. Local conditions may vary. Last updated: April 2026.

Sources & credits

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