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When to plant Salvia in Johnson County, KS

Johnson County's short 201-day growing season means one Salvia planting between April 8 and April 22. No fall crop in Zone 6b.

When to Plant Salvia in Johnson County, KS

Johnson County, Kansas Zone 6b June

June in the garden — Johnson County, Kansas

We've pulled the most time-sensitive tasks for Johnson County, Kansas this June and put them front and centre. Tackle them in order.

Avg. last frost April 8
Avg. first frost October 26
Soil temp (4") 73°F
Watering Low
Pest pressure High
Daylight 14.7 hrs
  1. Indoor seed-starting week for salvia

    Bottom-water once the first true leaves appear — it keeps stems dry and knocks back damping-off.

  2. Harvest salvia as they ripen

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

July prep starts now
  • 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.

Johnson County, Kansas is in USDA Zone 6b. The average last spring frost is April 8 and the first fall frost is October 26, giving you a growing season of approximately 201 days.

At an elevation of 768 feet, Johnson County receives approximately 27.6 inches of rainfall annually with predominantly loam soil. Summer highs average 87°F, providing good warmth for Salvia during the growing season.

Annual Blooms in Summer Pollinator-friendly Deer-resistant Good for cutting Fragrant
Johnson County, KS (Zone 6b) Long season
201 days
Last Spring Frost April 8
201 growing days
First Fall Frost October 26

Johnson County Soil Profile

Soil Type

Loam

Soil pH

6.8-7.2

Drainage

Well Drained

Salvia Planting Risk Windows

Early Start (70% safe) ✓ Fits season (26 days to spare)
Start indoors: Jan 31 Transplant: Apr 4 🌸 Bloom: Jun 13 – Sep 26
Recommended (50%) ✓ Fits season (26 days to spare)
Start indoors: Feb 4 Transplant: Apr 8 🌸 Bloom: Jun 17 – Sep 30
Safe Start (90%) ✓ Fits season (30 days to spare)
Start indoors: Feb 19 Transplant: Apr 23 🌸 Bloom: Jul 2 – Oct 15

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 Johnson County

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

Soil pH

Your soil pH (6.8–7.2) overlaps with Salvia's range (5.5–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.2%) — Salvia will thrive.

How to Plant Salvia

12"
Between Plants
18"
Between Rows

Succession Planting Salvia

3
successive plantings in your 201-day season

Sow every 8 weeks. Last sowing by Jul 28 to harvest before frost.

Salvia Water Budget

Plant needs
1.0″/week
Rainfall provides
0.6″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 909 gal / 100 sq ft
Drought risk

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

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 0.8" 0" ❄️ Dormant
Feb 0.8" 0" ❄️ Dormant
Mar 1.9" 0" ❄️ Dormant
Apr 4.3" 3.2" 1.1" 💧 Light watering
May 4.3" 3.7" 0.6" 💧 Light watering
Jun 4.3" 4.1" 0.2" 💧 Light watering
Jul 4.3" 3.8" 0.5" 💧 Light watering
Aug 4.3" 3.5" 0.8" 💧 Light watering
Sep 4.3" 2.3" 2" 💧 Light watering
Oct 4.3" 1.8" 2.5" 🚿 Regular watering
Nov 1" 0" ❄️ Dormant
Dec 0.7" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Johnson 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 ~1,220 GDD — county provides 3,065 GDD Excellent fit

Salvia Planting Timeline — Johnson County, KS

Salvia Planting Calendar

Activity When Date Range
Start Indoors February 4 Feb 4 – Feb 18
Transplant Outdoors April 8 Apr 8 – Apr 22
Bloom June 17 Jun 17 – Sep 30

· 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
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: acceptable

🗺️ USDA Zone

Zone 6b

📆 Growing Season

201 days in Johnson County

Growing Tips for Salvia in Johnson County

Direct sow Salvia outdoors after April 08 in Johnson 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 Johnson County, KS?

Johnson County is in Zone 6b with an average last frost of April 8. Plan your Salvia planting based on this frost date — see the calendar above for exact timing.

What planting zone is Johnson County, KS?

Johnson County, Kansas is in USDA Hardiness Zone 6b. The average last spring frost is April 8 and first fall frost is October 26.

When should I plant Salvia in Johnson County, KS?

In Johnson County, KS, plant Salvia after the last frost (around April 8) and before the first frost (around October 26). Best results when soil holds above 50°F.

What growing zone is Johnson County, KS for Salvia?

Johnson 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 Johnson County's climate?

Yes — Salvia grows well in Johnson County's temperate climate. Johnson County averages a 201-day frost-free season, with last frost around April 8 and first frost around October 26.

🌱

Your Johnson County Garden Planner — Free

A 22-page printable planner built for Johnson 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 Johnson County, KS. 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.