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When to plant Nasturtium in Saline County, IL

Saline County's spring Nasturtium window runs April 8 through April 29. most warm-season crops establish quickly once soil holds above 60°F.

When to Plant Nasturtium in Saline County, IL

Saline County, Illinois Zone 7a July

Top priorities for Saline County, Illinois gardeners in July

If you only do a handful of things in the garden this July, make it these. They're sequenced around your zone's frost timing.

Avg. last frost April 8
Avg. first frost October 24
Soil temp (4") 82°F
Watering Low
Pest pressure High
Daylight 14.4 hrs
  1. It's harvest week for nasturtium

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

A few tasks this July that'll pay off in August
  • 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.

Saline County, Illinois is in USDA Zone 7a. The average last spring frost is April 8 and the first fall frost is October 24, giving you a growing season of approximately 199 days.

At an elevation of 748 feet, Saline County receives approximately 41.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88°F, providing good warmth for Nasturtium during the growing season.

Annual Blooms in Multi-season Pollinator-friendly Deer-resistant Good for cutting Fragrant
Saline County, IL (Zone 7a) Moderate season
199 days
Last Spring Frost April 8
199 growing days
First Fall Frost October 24

Saline County Soil Profile

Soil Type

Silt Loam

Soil pH

6-6.7

Drainage

Well Drained

Nasturtium Planting Risk Windows

Early Start (70% safe) ✓ Fits season (14 days to spare)
Start indoors: Mar 7 Transplant: Apr 4 🌸 Bloom: May 30 – Oct 3
Recommended (50%) ✓ Fits season (17 days to spare)
Start indoors: Mar 11 Transplant: Apr 8 🌸 Bloom: Jun 3 – Oct 7
Safe Start (90%) ✓ Fits season (24 days to spare)
Start indoors: Mar 24 Transplant: Apr 21 🌸 Bloom: Jun 16 – Oct 20

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 Saline County

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

Soil pH

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

Soil Texture

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

Organic Matter

Organic matter is moderate (3.9%). 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 199-day season

Sow every 6.3 weeks. Last sowing by Aug 20 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 1.7" 0" ❄️ Dormant
Feb 2" 0" ❄️ Dormant
Mar 3.2" 0" ❄️ Dormant
Apr 2.2" 4.3" 0" ✅ Rainfall sufficient
May 2.2" 4.7" 0" ✅ Rainfall sufficient
Jun 2.2" 4.6" 0" ✅ Rainfall sufficient
Jul 2.2" 4.8" 0" ✅ Rainfall sufficient
Aug 2.2" 4.5" 0" ✅ Rainfall sufficient
Sep 2.2" 3.2" 0" ✅ Rainfall sufficient
Oct 2.2" 2.9" 0" ✅ Rainfall sufficient
Nov 2.9" 0" ❄️ Dormant
Dec 2.2" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Saline 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 ~960 GDD — county provides 3,184 GDD Excellent fit

Nasturtium Planting Timeline — Saline County, IL

Nasturtium Planting Calendar

Activity When Date Range
Start Indoors March 11 Mar 11 – Mar 25
Transplant Outdoors April 8 Apr 8 – Apr 22
Direct Sow April 8 Apr 8 – Apr 29
Bloom June 3 Jun 3 – Oct 7

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: ideal

🗺️ USDA Zone

Zone 7a

📆 Growing Season

199 days in Saline County

Growing Tips for Nasturtium in Saline County

Direct sow Nasturtium outdoors after April 08 in Saline 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 Saline County, IL?

Saline County is in Zone 7a with an average last frost of April 8. Plan your Nasturtium planting based on this frost date — see the calendar above for exact timing.

What planting zone is Saline County, IL?

Saline County, Illinois is in USDA Hardiness Zone 7a. The average last spring frost is April 8 and first fall frost is October 24.

When should I plant Nasturtium in Saline County, IL?

In Saline County, IL, plant Nasturtium after the last frost (around April 8) and before the first frost (around October 24). Best results when soil holds above 50°F.

What growing zone is Saline County, IL for Nasturtium?

Saline 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 Saline County's climate?

Yes — Nasturtium grows well in Saline County's temperate climate. Saline County averages a 199-day frost-free season, with last frost around April 8 and first frost around October 24.

🌱

Your Saline County Garden Planner — Free

A 22-page printable planner built for Saline 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 Saline County, IL. 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.