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When to Plant Nasturtium in Jefferson County, OH

Jefferson County, Ohio Zone 6b July

What to do in July

Welcome to July in Zone 6b. These are the moves that will have the biggest impact on your growing season.

Avg. last frost April 23
Avg. first frost October 29
Soil temp (4") 83°F
Watering Low
Pest pressure High
Daylight 14.6 hrs
  1. Harvest nasturtium as they ripen

    If you can't use it all right away, check the food-preservation section of your planner.

Coming up in August — start thinking about
  • First harvests: nasturtium

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Nasturtium (Tropaeolum majus) is a fast-growing annual with distinctive round, lily-pad leaves and bold trumpet-shaped blooms in warm oranges, reds, and yellows. Both the flowers and leaves are edible with a peppery watercress flavor. Planted near vegetables, nasturtiums act as a sacrifice trap-crop, luring aphids away from more valuable plants. They thrive in poor, dry soil — rich conditions produce lush foliage but few flowers.

Jefferson County, Ohio is in USDA Zone 6b. The average last spring frost is April 23 and the first fall frost is October 29, giving you a growing season of approximately 189 days.

At an elevation of 1,017 feet, Jefferson County receives approximately 39.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Nasturtium during the growing season.

Annual Blooms in Multi-season Pollinator-friendly Deer-resistant Good for cutting Fragrant
Jefferson County, OH (Zone 6b) Moderate season
189 days
Last Spring Frost April 23
189 growing days
First Fall Frost October 29

Jefferson County Soil Profile

Soil Type

Silt Loam

Soil pH

5.9-7.1

Drainage

Well Drained

Nasturtium Planting Risk Windows

Early Start (70% safe) ✓ Fits season (13 days to spare)
Start indoors: Mar 17 Transplant: Apr 14 🌸 Bloom: Jun 9 – Oct 6
Recommended (50%) ✓ Fits season (14 days to spare)
Start indoors: Mar 26 Transplant: Apr 23 🌸 Bloom: Jun 18 – Oct 15
Safe Start (90%) ✓ Fits season (9 days to spare)
Start indoors: Apr 11 Transplant: May 9 🌸 Bloom: Jul 4 – Oct 31

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 Jefferson County

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

Soil pH

Your soil pH (5.9–7.1) overlaps with Nasturtium's range (6.0–8.0), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Nasturtium.

Organic Matter

Organic matter is excellent (4.9%) — Nasturtium will thrive.

How to Plant Nasturtium

0.5"
Planting Depth
10"
Between Plants
12"
Between Rows

Succession Planting Nasturtium

4
successive plantings in your 189-day season

Sow every 6.3 weeks. Last sowing by Aug 25 to harvest before frost.

Nasturtium Water Budget

Plant needs
0.5″/week
Rainfall provides
0.9″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Nasturtium

Nasturtium needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.

Month Nasturtium Needs Rainfall You Supplement Action
Jan 1.6" 0" ❄️ Dormant
Feb 1.9" 0" ❄️ Dormant
Mar 2.6" 0" ❄️ Dormant
Apr 2.2" 3.6" 0" ✅ Rainfall sufficient
May 2.2" 4.5" 0" ✅ Rainfall sufficient
Jun 2.2" 4.6" 0" ✅ Rainfall sufficient
Jul 2.2" 5.2" 0" ✅ Rainfall sufficient
Aug 2.2" 4.2" 0" ✅ Rainfall sufficient
Sep 2.2" 3.6" 0" ✅ Rainfall sufficient
Oct 2.2" 3.3" 0" ✅ Rainfall sufficient
Nov 2.8" 0" ❄️ Dormant
Dec 2.1" 0" ❄️ Dormant

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

Nasturtium 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.

Nasturtium needs ~870 GDD — county provides 2,740 GDD Excellent fit

Nasturtium Planting Timeline — Jefferson County, OH

Nasturtium Planting Calendar

Activity When Date Range
Start Indoors March 26 Mar 26 – Apr 9
Transplant Outdoors April 23 Apr 23 – May 7
Direct Sow April 23 Apr 23 – May 14
Bloom June 18 Jun 18 – Oct 15

Plant 0.5" deep · 10" apart · Rows 12" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

55–65 days

🧪 Soil pH

Needs 6–8 · Your soil: acceptable

🗺️ USDA Zone

Zone 6b

📆 Growing Season

189 days in Jefferson County

Growing Tips for Nasturtium in Jefferson County

Direct sow Nasturtium outdoors after April 23 in Jefferson County when soil has warmed and frost danger has passed.

General growing tips

Direct-sow large seeds 1/2 inch deep after last frost; soak seeds overnight to speed germination (7-10 days). Nasturtiums dislike root disturbance so direct sowing is strongly preferred. Avoid fertilizing — poor soil brings the best bloom. Trailing types can cover banks and climb trellises; dwarf types suit containers. In hot climates (zones 9+) plant in fall for winter/spring bloom as plants struggle in peak summer heat.

Companion Planting

Good Companions

Avoid Planting Near

  • Fennel

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Nasturtium in Jefferson County, OH?

Jefferson County is in Zone 6b with an average last frost of April 23. Plan your Nasturtium planting based on this frost date — see the calendar above for exact timing.

What planting zone is Jefferson County, OH?

Jefferson County, Ohio is in USDA Hardiness Zone 6b. The average last spring frost is April 23 and first fall frost is October 29.

🌱

Your Jefferson County Garden Planner — Free

A 22-page printable planner built for Jefferson 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.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Jefferson County, OH. Local conditions may vary. Last updated: July 2026.

Sources & credits

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