When to Plant Cranberries in Swain County, NC
May in the garden — Swain County, North Carolina
Welcome to May in Zone 7a. These are the moves that will have the biggest impact on your growing season.
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Harden off and plant cranberries
Bring a watering can to the bed. Each transplant gets a drink the moment it's in the ground, not ten minutes later.
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.
Swain County, North Carolina is in USDA Zone 7a. The average last spring frost is April 24 and the first fall frost is October 17, giving you a growing season of approximately 176 days.
At an elevation of 2,612 feet, Swain County receives approximately 47.6 inches of rainfall annually with predominantly clay loam soil. Summer highs average 86°F, providing good warmth for Cranberries during the growing season. Clay soil retains moisture well for Cranberries, but amend with compost to improve drainage and prevent root rot.
Swain County Soil Profile
Soil Type
Clay Loam
Soil pH
5.4-6.7
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 Swain County
How your county's soil matches Cranberries's growing requirements.
Soil pH
Your soil pH (5.4–6.7) is more alkaline than Cranberries prefers (4.0–5.5). Add sulfur or peat moss to lower pH.
Soil Texture
The clay loam soil in Swain County is excellent for Cranberries — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Cranberries.
Organic Matter
Organic matter is moderate (2.9%). Annual compost additions will help Cranberries.
How to Plant Cranberries
Plant Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
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 | — | 3.8" | 0" | ❄️ Dormant |
| Feb | — | 3.9" | 0" | ❄️ Dormant |
| Mar | — | 4.7" | 0" | ❄️ Dormant |
| Apr | 6.5" | 4" | 2.5" | 💧 Light watering |
| May | 6.5" | 4.3" | 2.2" | 💧 Light watering |
| Jun | 6.5" | 4.7" | 1.8" | 💧 Light watering |
| Jul | 6.5" | 4.8" | 1.7" | 💧 Light watering |
| Aug | 6.5" | 3.9" | 2.6" | 💧 Light watering |
| Sep | 6.5" | 3.1" | 3.4" | 🚿 Regular watering |
| Oct | 6.5" | 2.9" | 3.6" | 🚿 Regular watering |
| Nov | — | 3.5" | 0" | ❄️ Dormant |
| Dec | — | 3.9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Swain 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 Planting Timeline — Swain County, NC
Cranberries Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | May 15 | May 15 – May 29 |
· 36" apart · Rows 48" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | Transplant Outdoors |
| June | — |
| July | — |
| August | — |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1.5"/week · Natural rainfall sufficient
📅 Days to Maturity
730–1095 days
🧪 Soil pH
Needs 4–5.5 · Your soil: too_alkaline
🗺️ USDA Zone
Zone 7a
📆 Growing Season
176 days in Swain County
Growing Tips for Cranberries in Swain County
Direct sow Cranberries outdoors after April 24 in Swain County when soil has warmed and frost danger has passed.
With Swain County's clay soil (31% clay), work in 3-4 inches of compost before planting Cranberries. Avoid tilling when soil is wet to prevent compaction.
Your 176.0-day growing season in Swain 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 →
Cranberries in Other Locations
Frequently Asked Questions
When should I plant Cranberries in Swain County, NC?
Swain County is in Zone 7a with an average last frost of April 24. Plan your Cranberries planting based on this frost date — see the calendar above for exact timing.
What planting zone is Swain County, NC?
Swain County, North Carolina is in USDA Hardiness Zone 7a. The average last spring frost is April 24 and first fall frost is October 17.
Your Swain County Garden Planner — Free
A 24-page printable planner built for Swain County (Zone 7a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.