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When to Plant Boysenberries in McNairy County, TN

McNairy County, Tennessee Zone 7b May

McNairy County, Tennessee gardeners: here's your May plan

Here's what deserves your attention in McNairy County, Tennessee this month. Everything below is tailored to Zone 7b and timed around your local frost dates.

Avg. last frost March 31
Avg. first frost October 28
Soil temp (4") 62°F
Watering Low
Pest pressure Moderate
Daylight 13.8 hrs

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Boysenberries are a cross between raspberries, blackberries, and loganberries, producing large, dark, intensely flavored berries. They are excellent for jams and pies.

McNairy County, Tennessee is in USDA Zone 7b. The average last spring frost is March 31 and the first fall frost is October 28, giving you a growing season of approximately 211 days.

At an elevation of 3,207 feet, McNairy County receives approximately 46 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Boysenberries during the growing season.

McNairy County, TN (Zone 7b) Long season
211 days
Last Spring Frost March 31
211 growing days
First Fall Frost October 28
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McNairy County Soil Profile

Soil Type

Silt Loam

Soil pH

5.4-7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season
Transplant: Apr 14
Recommended (50%) ✓ Fits season
Transplant: Apr 21
Safe Start (90%) ✓ Fits season
Transplant: May 7

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 McNairy County

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

Soil pH

Your soil pH (5.4–7.0) overlaps with Boysenberries's range (5.5–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.7%). Annual compost additions will help Boysenberries.

How to Plant Boysenberries

24"
Between Plants
72"
Between Rows

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 158 gal / 100 sq ft

Monthly Watering Guide for Boysenberries

Boysenberries needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Boysenberries Needs Rainfall You Supplement Action
Jan 3.6" 0" ❄️ Dormant
Feb 4.1" 0" ❄️ Dormant
Mar 4.3" 4.3" 0" ✅ Rainfall sufficient
Apr 4.3" 3.2" 1.1" 💧 Light watering
May 4.3" 3.9" 0.4" 💧 Light watering
Jun 4.3" 4.2" 0.1" 💧 Light watering
Jul 4.3" 5" 0" ✅ Rainfall sufficient
Aug 4.3" 4.8" 0" ✅ Rainfall sufficient
Sep 4.3" 3.2" 1.1" 💧 Light watering
Oct 4.3" 3.1" 1.2" 💧 Light watering
Nov 3.2" 0" ❄️ Dormant
Dec 3.4" 0" ❄️ Dormant

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

Boysenberries 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.

Boysenberries needs ~9,171 GDD — county provides 3,534 GDD May not mature

Boysenberries Planting Timeline — McNairy County, TN

Boysenberries Planting Calendar

Activity When Date Range
Transplant Outdoors April 21 Apr 21 – May 5

· 24" apart · Rows 72" apart

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

365–730 days

🧪 Soil pH

Needs 5.5–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 7b

📆 Growing Season

211 days in McNairy County

Growing Tips for Boysenberries in McNairy County

Direct sow Boysenberries outdoors after March 31 in McNairy County when soil has warmed and frost danger has passed.

Your 211.0-day growing season in McNairy County is tight for Boysenberries (365.0-730.0 days to maturity). Start indoors and choose early-maturing varieties.

General growing tips

Provide strong trellising for vigorous canes. Prune spent canes to ground after harvest. Mulch heavily to retain moisture. Protect from wind to prevent cane damage.

Companion Planting

Good Companions

Avoid Planting Near

  • Tomatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Boysenberries in McNairy County, TN?

McNairy County is in Zone 7b with an average last frost of March 31. Plan your Boysenberries planting based on this frost date — see the calendar above for exact timing.

What planting zone is McNairy County, TN?

McNairy County, Tennessee is in USDA Hardiness Zone 7b. The average last spring frost is March 31 and first fall frost is October 28.

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Your McNairy County Garden Planner — Free

A 24-page printable planner built for McNairy County (Zone 7b). 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 McNairy County, TN. 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.