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When to plant Zinnia in Stevens County, KS

Stevens County gardeners should plant Zinnia between April 20 and May 11 in spring. With Stevens County's Zone 6b climate (last frost April 20), Zinnia needs 60–70 days to mature — plant by August 7 for a full harvest.

When to Plant Zinnia in Stevens County, KS

Stevens County, Kansas Zone 6b June

Your June game plan for Stevens County, Kansas

June is a pivotal month for Stevens County, Kansas gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost April 20
Avg. first frost October 16
Soil temp (4") 74°F
Watering High
Pest pressure High
Daylight 14.5 hrs
  1. Basket week: zinnia

    Check every 1–2 days. Many of these get tough or go to seed if you wait too long.

A few tasks this June that'll pay off in July
  • First harvests: zinnia

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Zinnia (Zinnia elegans) is a fast-growing, heat-loving annual that produces bold, dahlia-like blooms from early summer until hard frost. One of the easiest flowers to grow from direct-sown seed, zinnias thrive in hot, dry conditions and are magnets for butterflies and beneficial insects. They make excellent companion plants alongside marigolds in the vegetable garden.

Stevens County, Kansas is in USDA Zone 6b. The average last spring frost is April 20 and the first fall frost is October 16, giving you a growing season of approximately 179 days.

At an elevation of 1,123 feet, Stevens County receives approximately 31.9 inches of rainfall annually with predominantly loam soil. Summer highs average 86°F, providing good warmth for Zinnia during the growing season.

Annual Blooms in Summer Pollinator-friendly Deer-resistant Good for cutting
Stevens County, KS (Zone 6b) Moderate season
179 days
Last Spring Frost April 20
179 growing days
First Fall Frost October 16

Stevens County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.8

Drainage

Well Drained

Zinnia Planting Risk Windows

Early Start (70% safe) ✓ Fits season (13 days to spare)
Start indoors: Mar 18 Transplant: Apr 15 🌸 Bloom: Jun 24 – Sep 30
Recommended (50%) ✓ Fits season (11 days to spare)
Start indoors: Mar 23 Transplant: Apr 20 🌸 Bloom: Jun 29 – Oct 5
Safe Start (90%) ✓ Fits season (12 days to spare)
Start indoors: Apr 6 Transplant: May 4 🌸 Bloom: Jul 13 – Oct 19

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 Stevens County

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

Soil pH

Your soil pH (6.5–7.8) overlaps with Zinnia's range (5.5–7.5), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Zinnia.

Organic Matter

Organic matter is moderate (3.9%). Annual compost additions will help Zinnia.

How to Plant Zinnia

0.3"
Planting Depth
12"
Between Plants
18"
Between Rows

Succession Planting Zinnia

3
successive plantings in your 179-day season

Sow every 6.9 weeks. Last sowing by Aug 07 to harvest before frost.

Zinnia 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 8/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Zinnia

Zinnia 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 Zinnia Needs Rainfall You Supplement Action
Jan 2.4" 0" ❄️ Dormant
Feb 1.7" 0" ❄️ Dormant
Mar 2.9" 0" ❄️ Dormant
Apr 2.2" 3.1" 0" ✅ Rainfall sufficient
May 2.2" 3.9" 0" ✅ Rainfall sufficient
Jun 2.2" 2.5" 0" ✅ Rainfall sufficient
Jul 2.2" 2.7" 0" ✅ Rainfall sufficient
Aug 2.2" 3" 0" ✅ Rainfall sufficient
Sep 2.2" 2.5" 0" ✅ Rainfall sufficient
Oct 2.2" 2.8" 0" ✅ Rainfall sufficient
Nov 2.4" 0" ❄️ Dormant
Dec 1.9" 0" ❄️ Dormant

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

Zinnia 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.

Zinnia needs ~942 GDD — county provides 2,595 GDD Excellent fit

Zinnia Planting Timeline — Stevens County, KS

Zinnia Planting Calendar

Activity When Date Range
Start Indoors March 23 Mar 23 – Apr 6
Transplant Outdoors April 20 Apr 20 – May 4
Direct Sow April 20 Apr 20 – May 11
Bloom June 29 Jun 29 – Oct 5

Plant 0.3" deep · 12" apart · Rows 18" apart

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Start Indoors 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

60–70 days

🧪 Soil pH

Needs 5.5–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 6b

📆 Growing Season

179 days in Stevens County

Growing Tips for Zinnia in Stevens County

Direct sow Zinnia outdoors after April 20 in Stevens County when soil has warmed and frost danger has passed.

Common pests for Zinnia in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.

General growing tips

Direct-sow after last frost when soil reaches 60°F; seeds germinate in 5-7 days. In zones 3-5 a brief indoor start (4 weeks) is worthwhile but transplant carefully — zinnias dislike root disturbance. Deadhead frequently to extend bloom. Excellent cut flower; harvesting regularly encourages branching. Avoid overhead watering to reduce powdery mildew.

Companion Planting

Good Companions

Avoid Planting Near

  • Fennel

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Zinnia in Stevens County, KS?

Stevens County is in Zone 6b with an average last frost of April 20. Plan your Zinnia planting based on this frost date — see the calendar above for exact timing.

What planting zone is Stevens County, KS?

Stevens County, Kansas is in USDA Hardiness Zone 6b. The average last spring frost is April 20 and first fall frost is October 16.

When should I plant Zinnia in Stevens County, KS?

In Stevens County, KS, plant Zinnia after the last frost (around April 20) and before the first frost (around October 16). Best results when soil holds above 50°F.

What growing zone is Stevens County, KS for Zinnia?

Stevens County sits in USDA Zone 6b. Zinnia grows reliably in zones 3a through 11b, so it's a good fit here.

Can Zinnia grow in Stevens County's climate?

Yes — Zinnia grows well in Stevens County's temperate climate. Stevens County averages a 179-day frost-free season, with last frost around April 20 and first frost around October 16.

🌱

Your Stevens County Garden Planner — Free

A 22-page printable planner built for Stevens 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 Stevens County, KS. Local conditions may vary. Last updated: June 2026.

Sources & credits

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