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When to Plant Cucumber in Washington County, TN

Washington County, Tennessee Zone 7b May

May in the garden — Washington County, Tennessee

May is a pivotal month for Washington County, Tennessee gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost April 15
Avg. first frost October 22
Soil temp (4") 55°F
Watering Moderate
Pest pressure Low
Daylight 13.9 hrs
  1. Time to start cucumber inside

    You're about 23 weeks out from your last frost — the perfect window to get these germinating indoors.

A few tasks this May that'll pay off in June
  • First harvests: cucumber

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Cucumbers are a warm-season vine crop available in slicing and pickling varieties. They are prolific producers when given warmth, moisture, and a trellis to climb.

Washington County, Tennessee is in USDA Zone 7b. The average last spring frost is April 15 and the first fall frost is October 22, giving you a growing season of approximately 190 days.

At an elevation of 2,969 feet, Washington County receives approximately 41.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Cucumber during the growing season.

Washington County, TN (Zone 7b) Moderate season
190 days
Last Spring Frost April 15
190 growing days
First Fall Frost October 22

Washington County Soil Profile

Soil Type

Silt Loam

Soil pH

5.5-7.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (66 days to spare)
Start indoors: Mar 12 Transplant: Apr 23 🍅 Harvest: Jun 18 – Aug 13
Recommended (50%) ✓ Fits season (64 days to spare)
Start indoors: Mar 18 Transplant: Apr 29 🍅 Harvest: Jun 24 – Aug 19
Safe Start (90%) ✓ Fits season (59 days to spare)
Start indoors: Apr 4 Transplant: May 16 🍅 Harvest: Jul 11 – Sep 5

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 Washington County

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

Soil pH

Your soil pH (5.5–7.1) overlaps with Cucumber's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.5%). Annual compost additions will help Cucumber.

How to Plant Cucumber

0.5"
Planting Depth
24"
Between Plants
48"
Between Rows

Succession Planting Cucumber

4
successive plantings in your 190-day season

Sow every 5.7 weeks. Last sowing by Aug 13 to harvest before frost.

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 993 gal / 100 sq ft

Monthly Watering Guide for Cucumber

Cucumber 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 Cucumber Needs Rainfall You Supplement Action
Jan 3.4" 0" ❄️ Dormant
Feb 3.6" 0" ❄️ Dormant
Mar 3.8" 0" ❄️ Dormant
Apr 6.5" 3.2" 3.3" 🚿 Regular watering
May 6.5" 2.8" 3.7" 🚿 Regular watering
Jun 6.5" 3.4" 3.1" 💧 Light watering
Jul 6.5" 4.3" 2.2" 💧 Light watering
Aug 6.5" 3.6" 2.9" 💧 Light watering
Sep 6.5" 3.4" 3.1" 💧 Light watering
Oct 6.5" 2.9" 3.6" 🚿 Regular watering
Nov 3.5" 0" ❄️ Dormant
Dec 3.4" 0" ❄️ Dormant

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

Cucumber 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.

Cucumber needs ~1,005 GDD — county provides 3,182 GDD Excellent fit

Cucumber Planting Timeline — Washington County, TN

Cucumber Planting Calendar

Activity When Date Range
Start Indoors March 18 Mar 18 – Apr 1
Transplant Outdoors April 29 Apr 29 – May 13
Direct Sow April 22 Apr 22 – May 13
Harvest June 24 Jun 24 – Aug 19

Plant 0.5" deep · 24" apart · Rows 48" apart

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Start Indoors Transplant Outdoors Direct Sow
May Transplant Outdoors Direct Sow
June Harvest
July Harvest
August Harvest
September
October
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.5"/week · 1-2 times/week

📅 Days to Maturity

50–70 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 7b

📆 Growing Season

190 days in Washington County

Growing Tips for Cucumber in Washington County

Direct sow Cucumber outdoors after April 15 in Washington County when soil has warmed and frost danger has passed.

Common pests for Cucumber in this region include squash vine borer and cucumber beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

Direct sow after last frost or start indoors 3 weeks early. Provide a trellis for vining types to save space and improve air circulation. Harvest frequently to encourage production.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes
  • Sage

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Cucumber in Washington County, TN?

Washington County is in Zone 7b with an average last frost of April 15. Plan your Cucumber planting based on this frost date — see the calendar above for exact timing.

What planting zone is Washington County, TN?

Washington County, Tennessee is in USDA Hardiness Zone 7b. The average last spring frost is April 15 and first fall frost is October 22.

🌱

Your Washington County Garden Planner — Free

A 24-page printable planner built for Washington 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 Washington 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.