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When to plant Salvia in Marion County, IL

Marion County's 192-day season only supports one Salvia planting per year. Sow between April 10 and April 24 for the best chance at full maturity before October 19.

When to Plant Salvia in Marion County, IL

Marion County, Illinois Zone 6b June

June in the garden — Marion County, Illinois

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

Avg. last frost April 10
Avg. first frost October 19
Soil temp (4") 74°F
Watering Low
Pest pressure High
Daylight 14.7 hrs
  1. Get salvia seeds going inside

    Give them 6–8 weeks indoors before the last frost and you'll transplant into warm soil with seedlings that are already leaping.

  2. Bring in the salvia

    Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.

July will be here before you know it — start on
  • First harvests: salvia

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Salvia splendens is a tender perennial from Brazil grown as a warm-season annual throughout the US. Its vivid, upright flower spikes in brilliant red, purple, and coral are irresistible to hummingbirds, bees, and butterflies. One of the longest-blooming annuals in the landscape — plants bloom from early summer until hard frost with minimal deadheading required.

Marion County, Illinois is in USDA Zone 6b. The average last spring frost is April 10 and the first fall frost is October 19, giving you a growing season of approximately 192 days.

At an elevation of 964 feet, Marion County receives approximately 40.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Salvia during the growing season.

Annual Blooms in Summer Pollinator-friendly Deer-resistant Good for cutting Fragrant
Marion County, IL (Zone 6b) Moderate season
192 days
Last Spring Frost April 10
192 growing days
First Fall Frost October 19

Marion County Soil Profile

Soil Type

Silt Loam

Soil pH

6.1-7

Drainage

Well Drained

Salvia Planting Risk Windows

Early Start (70% safe) ✓ Fits season (17 days to spare)
Start indoors: Feb 1 Transplant: Apr 5 🌸 Bloom: Jun 14 – Sep 27
Recommended (50%) ✓ Fits season (17 days to spare)
Start indoors: Feb 6 Transplant: Apr 10 🌸 Bloom: Jun 19 – Oct 2
Safe Start (90%) ✓ Fits season (19 days to spare)
Start indoors: Feb 16 Transplant: Apr 20 🌸 Bloom: Jun 29 – Oct 12

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 Marion County

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

Soil pH

Your soil pH (6.1–7.0) is within Salvia's preferred range (5.5–7.0).

Soil Texture

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

Drainage

Drainage is adequate for Salvia.

Organic Matter

Organic matter is excellent (4.4%) — Salvia will thrive.

How to Plant Salvia

12"
Between Plants
18"
Between Rows

Succession Planting Salvia

3
successive plantings in your 192-day season

Sow every 8 weeks. Last sowing by Jul 21 to harvest before frost.

Salvia Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 708 gal / 100 sq ft

Monthly Watering Guide for Salvia

Salvia needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Salvia Needs Rainfall You Supplement Action
Jan 1.7" 0" ❄️ Dormant
Feb 1.7" 0" ❄️ Dormant
Mar 2.7" 0" ❄️ Dormant
Apr 4.3" 3.4" 0.9" 💧 Light watering
May 4.3" 5" 0" ✅ Rainfall sufficient
Jun 4.3" 5.2" 0" ✅ Rainfall sufficient
Jul 4.3" 3.8" 0.5" 💧 Light watering
Aug 4.3" 4.7" 0" ✅ Rainfall sufficient
Sep 4.3" 3.3" 1" 💧 Light watering
Oct 4.3" 3.3" 1" 💧 Light watering
Nov 3.1" 0" ❄️ Dormant
Dec 2.4" 0" ❄️ Dormant

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

Salvia 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.

Salvia needs ~1,340 GDD — county provides 3,216 GDD Excellent fit

Salvia Planting Timeline — Marion County, IL

Salvia Planting Calendar

Activity When Date Range
Start Indoors February 6 Feb 6 – Feb 20
Transplant Outdoors April 10 Apr 10 – Apr 24
Bloom June 19 Jun 19 – Oct 2

· 12" apart · Rows 18" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

70–90 days

🧪 Soil pH

Needs 5.5–7 · Your soil: ideal

🗺️ USDA Zone

Zone 6b

📆 Growing Season

192 days in Marion County

Growing Tips for Salvia in Marion County

Direct sow Salvia outdoors after April 10 in Marion County when soil has warmed and frost danger has passed.

General growing tips

Start indoors 8-10 weeks before last frost; seeds need 65-70°F soil and light to germinate (surface-sow, do not cover). Transplant after last frost when soil has warmed. Salvia is frost-sensitive — even a light frost kills plants. Pinch spent spikes to encourage continued bloom. Tolerates heat and humidity well once established. In zones 9b-11b can be grown as a short-lived perennial.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Salvia in Marion County, IL?

Marion County is in Zone 6b with an average last frost of April 10. Plan your Salvia planting based on this frost date — see the calendar above for exact timing.

What planting zone is Marion County, IL?

Marion County, Illinois is in USDA Hardiness Zone 6b. The average last spring frost is April 10 and first fall frost is October 19.

When should I plant Salvia in Marion County, IL?

In Marion County, IL, plant Salvia after the last frost (around April 10) and before the first frost (around October 19). Best results when soil holds above 50°F.

What growing zone is Marion County, IL for Salvia?

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

Can Salvia grow in Marion County's climate?

Yes — Salvia grows well in Marion County's temperate climate. Marion County averages a 192-day frost-free season, with last frost around April 10 and first frost around October 19.

🌱

Your Marion County Garden Planner — Free

A 22-page printable planner built for Marion 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.

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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 Marion County, IL. Local conditions may vary. Last updated: June 2026.

Sources & credits

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