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When to plant Nasturtium in Greene County County,

Greene County County gardeners should plant Nasturtium between April 20 and May 11 in spring. With Greene County County's Zone 6a climate (last frost April 13), Nasturtium needs 65 days to mature — plant by August 17 for a full harvest.

When to Plant Nasturtium in Greene County, IL

Greene County, Illinois Zone 6a June

Your June gardening checklist

Here's what deserves your attention in Greene County, Illinois this month. Everything below is tailored to Zone 6a and timed around your local frost dates.

Avg. last frost April 13
Avg. first frost October 21
Soil temp (4") 68°F
Watering Low
Pest pressure High
Daylight 14.8 hrs
  1. It's harvest week for nasturtium

    This is the payoff month. Bring a basket, bring a friend, and get into the beds.

Coming up in July — 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.

Greene County, Illinois is in USDA Zone 6a. The average last spring frost is April 13 and the first fall frost is October 21, giving you a growing season of approximately 191 days.

At an elevation of 1,248 feet, Greene County receives approximately 37 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
Greene County, IL (Zone 6a) Moderate season
191 days
Last Spring Frost April 13
191 growing days
First Fall Frost October 21

Greene County Soil Profile

Soil Type

Silt Loam

Soil pH

6.1-6.7

Drainage

Well Drained

Nasturtium Planting Risk Windows

Early Start (70% safe) ✓ Fits season (15 days to spare)
Start indoors: Mar 10 Transplant: Apr 14 🌸 Bloom: Jun 9 – Sep 29
Recommended (50%) ✓ Fits season (16 days to spare)
Start indoors: Mar 16 Transplant: Apr 20 🌸 Bloom: Jun 15 – Oct 5
Safe Start (90%) ✓ Fits season (15 days to spare)
Start indoors: Mar 28 Transplant: May 2 🌸 Bloom: Jun 27 – Oct 17

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 Greene County

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

Soil pH

Your soil pH (6.1–6.7) is within Nasturtium's preferred range (6.0–8.0).

Soil Texture

The silt loam soil in Greene 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 (4.5%) — 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 191-day season

Sow every 6.3 weeks. Last sowing by Aug 17 to harvest before frost.

Nasturtium Water Budget

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

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

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 1.7" 0" ❄️ Dormant
Mar 2.7" 0" ❄️ Dormant
Apr 2.2" 3.2" 0" ✅ Rainfall sufficient
May 2.2" 3.9" 0" ✅ Rainfall sufficient
Jun 2.2" 4.5" 0" ✅ Rainfall sufficient
Jul 2.2" 3.9" 0" ✅ Rainfall sufficient
Aug 2.2" 4.4" 0" ✅ Rainfall sufficient
Sep 2.2" 3.3" 0" ✅ Rainfall sufficient
Oct 2.2" 3" 0" ✅ Rainfall sufficient
Nov 2.6" 0" ❄️ Dormant
Dec 2.2" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Greene 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 2,769 GDD Excellent fit

Nasturtium Planting Timeline — Greene County, IL

Nasturtium Planting Calendar

Activity When Date Range
Start Indoors March 16 Mar 16 – Mar 30
Transplant Outdoors April 20 Apr 20 – May 4
Direct Sow April 20 Apr 20 – May 11
Bloom June 15 Jun 15 – Oct 5

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 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: ideal

🗺️ USDA Zone

Zone 6a

📆 Growing Season

191 days in Greene County

Growing Tips for Nasturtium in Greene County

Direct sow Nasturtium outdoors after April 13 in Greene 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 Greene County, IL?

Greene County is in Zone 6a with an average last frost of April 13. Plan your Nasturtium planting based on this frost date — see the calendar above for exact timing.

What planting zone is Greene County, IL?

Greene County, Illinois is in USDA Hardiness Zone 6a. The average last spring frost is April 13 and first fall frost is October 21.

When should I plant Nasturtium in Greene County, ?

In Greene County, , plant Nasturtium after the last frost (around April 13) and before the first frost (around October 21). Best results when soil holds above 50°F.

What growing zone is Greene County, for Nasturtium?

Greene County sits in USDA Zone 6a. Nasturtium grows reliably in zones 2a through 11b, so it's a good fit here.

Can Nasturtium grow in Greene County's climate?

Yes — Nasturtium grows well in Greene County's temperate climate. Greene County averages a 191-day frost-free season, with last frost around April 13 and first frost around October 21.

🌱

Your Greene County Garden Planner — Free

A 22-page printable planner built for Greene County (Zone 6a). 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 Greene County, IL. Local conditions may vary. Last updated: June 2026.

Sources & credits

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