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When to plant Nasturtium in Jefferson County County,

The best window to plant Nasturtium in Jefferson County County, is April 7–April 28, when soil warms to 50°F. Last frost typically hits April 7; first frost October 30.

When to Plant Nasturtium in Jefferson County, KY

Jefferson County, Kentucky Zone 7a June

June in Jefferson County, Kentucky — your action list

Each item below is timed to Jefferson County, Kentucky's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost April 7
Avg. first frost October 30
Soil temp (4") 66°F
Watering Low
Pest pressure High
Daylight 14.6 hrs
  1. Bring in the nasturtium

    Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.

To set up a strong July, finish these tasks
  • 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, Kentucky is in USDA Zone 7a. The average last spring frost is April 7 and the first fall frost is October 30, giving you a growing season of approximately 206 days.

At an elevation of 3,279 feet, Jefferson County receives approximately 43.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°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, KY (Zone 7a) Long season
206 days
Last Spring Frost April 7
206 growing days
First Fall Frost October 30

Jefferson County Soil Profile

Soil Type

Silt Loam

Soil pH

5.2-6.6

Drainage

Well Drained

Nasturtium Planting Risk Windows

Early Start (70% safe) ✓ Fits season (26 days to spare)
Start indoors: Mar 1 Transplant: Mar 29 🌸 Bloom: May 24 – Sep 27
Recommended (50%) ✓ Fits season (24 days to spare)
Start indoors: Mar 10 Transplant: Apr 7 🌸 Bloom: Jun 2 – Oct 6
Safe Start (90%) ✓ Fits season (18 days to spare)
Start indoors: Mar 27 Transplant: Apr 24 🌸 Bloom: Jun 19 – Oct 23

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 (5.2–6.6) is more acidic than Nasturtium prefers (6.0–8.0). Add garden lime to raise pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.6%). Annual compost additions will help Nasturtium.

How to Plant Nasturtium

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

Succession Planting Nasturtium

4
successive plantings in your 206-day season

Sow every 6.3 weeks. Last sowing by Aug 26 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 3.2" 0" ❄️ Dormant
Feb 3.2" 0" ❄️ Dormant
Mar 4.5" 0" ❄️ Dormant
Apr 2.2" 2.9" 0" ✅ Rainfall sufficient
May 2.2" 3.6" 0" ✅ Rainfall sufficient
Jun 2.2" 4.1" 0" ✅ Rainfall sufficient
Jul 2.2" 3.9" 0" ✅ Rainfall sufficient
Aug 2.2" 4.5" 0" ✅ Rainfall sufficient
Sep 2.2" 3.7" 0" ✅ Rainfall sufficient
Oct 2.2" 2.5" 0" ✅ Rainfall sufficient
Nov 3.2" 0" ❄️ Dormant
Dec 3.8" 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 ~825 GDD — county provides 2,832 GDD Excellent fit

Nasturtium Planting Timeline — Jefferson County, KY

Nasturtium Planting Calendar

Activity When Date Range
Start Indoors March 10 Mar 10 – Mar 24
Transplant Outdoors April 7 Apr 7 – Apr 21
Direct Sow April 7 Apr 7 – Apr 28
Bloom June 2 Jun 2 – Oct 6

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

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Transplant Outdoors Direct Sow
May
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: too_acidic

🗺️ USDA Zone

Zone 7a

📆 Growing Season

206 days in Jefferson County

Growing Tips for Nasturtium in Jefferson County

Direct sow Nasturtium outdoors after April 07 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, KY?

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

What planting zone is Jefferson County, KY?

Jefferson County, Kentucky is in USDA Hardiness Zone 7a. The average last spring frost is April 7 and first fall frost is October 30.

When should I plant Nasturtium in Jefferson County County, ?

In Jefferson County County, , plant Nasturtium after the last frost (around April 7) and before the first frost (around October 30). Best results when soil holds above 50°F.

What growing zone is Jefferson County County, for Nasturtium?

Jefferson County County sits in USDA Zone 7a. Nasturtium grows reliably in zones 2a through 11b, so it's a good fit here.

Can Nasturtium grow in Jefferson County County's climate?

Yes — Nasturtium grows well in Jefferson County County's temperate climate. Jefferson County County averages a 206-day frost-free season, with last frost around April 7 and first frost around October 30.

🌱

Your Jefferson County Garden Planner — Free

A 22-page printable planner built for Jefferson 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.

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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 Jefferson County, KY. Local conditions may vary. Last updated: June 2026.

Sources & credits

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