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When to Plant Rhubarb in Robertson County, TN

Robertson County, Tennessee Zone 6b April

Robertson County, Tennessee gardeners: here's your April plan

April rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Robertson County, Tennessee.

Avg. last frost April 6
Avg. first frost October 29
Soil temp (4") 42°F
Watering Moderate
Pest pressure Low
Daylight 12.9 hrs
  1. Get rhubarb in the ground

    Pick a cloudy afternoon or evening to plant. Less transplant shock, and your seedlings will barely blink.

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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.

Robertson County, Tennessee is in USDA Zone 6b. The average last spring frost is April 6 and the first fall frost is October 29, giving you a growing season of approximately 206 days.

At an elevation of 3,620 feet, Robertson County receives approximately 42.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Rhubarb during the growing season.

Robertson County, TN (Zone 6b) Long season
206 days
Last Spring Frost April 6
206 growing days
First Fall Frost October 29
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Robertson County Soil Profile

Soil Type

Silt Loam

Soil pH

5.3-7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season
Transplant: Apr 20
Recommended (50%) ✓ Fits season
Transplant: Apr 27
Safe Start (90%) ✓ Fits season
Transplant: May 10

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 Robertson County

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

Soil pH

Your soil pH (5.3–7.0) overlaps with Rhubarb's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.1%). 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
0.9″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 280 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 3.1" 0" ❄️ Dormant
Feb 3.8" 0" ❄️ Dormant
Mar 3.7" 0" ❄️ Dormant
Apr 4.3" 3.1" 1.2" 💧 Light watering
May 4.3" 3.6" 0.7" 💧 Light watering
Jun 4.3" 3.5" 0.8" 💧 Light watering
Jul 4.3" 4.6" 0" ✅ Rainfall sufficient
Aug 4.3" 4.4" 0" ✅ Rainfall sufficient
Sep 4.3" 2.9" 1.4" 💧 Light watering
Oct 4.3" 2.9" 1.4" 💧 Light watering
Nov 3.4" 0" ❄️ Dormant
Dec 3.7" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Robertson 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 ~8,349 GDD — county provides 3,141 GDD May not mature

Rhubarb Planting Timeline — Robertson County, TN

Rhubarb Planting Calendar

Activity When Date Range
Transplant Outdoors April 27 Apr 27 – May 11

Plant 1" deep · 30" apart · Rows 42" 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 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 6b

📆 Growing Season

206 days in Robertson County

Growing Tips for Rhubarb in Robertson County

Direct sow Rhubarb outdoors after April 06 in Robertson County when soil has warmed and frost danger has passed.

Your 206.0-day growing season in Robertson 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 Robertson County, TN?

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

What planting zone is Robertson County, TN?

Robertson County, Tennessee is in USDA Hardiness Zone 6b. The average last spring frost is April 6 and first fall frost is October 29.

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Your Robertson County Garden Planner — Free

A 24-page printable planner built for Robertson 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 Robertson County, TN. Local conditions may vary. Last updated: April 2026.

Sources & credits

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