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When to plant Zinnia in Doniphan County County,

Zinnia planted in Doniphan County County between April 24 and May 15 matures in 70 days — well before the October 18 first frost.

When to Plant Zinnia in Doniphan County, KS

Doniphan County, Kansas Zone 6a June

Your June game plan for Doniphan County, Kansas

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Avg. last frost April 17
Avg. first frost October 18
Soil temp (4") 69°F
Watering Low
Pest pressure High
Daylight 14.8 hrs
Get ahead of 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.

Doniphan County, Kansas is in USDA Zone 6a. The average last spring frost is April 17 and the first fall frost is October 18, giving you a growing season of approximately 184 days.

At an elevation of 491 feet, Doniphan County receives approximately 26.7 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
Doniphan County, KS (Zone 6a) Moderate season
184 days
Last Spring Frost April 17
184 growing days
First Fall Frost October 18

Doniphan County Soil Profile

Soil Type

Loam

Soil pH

6.8-7.3

Drainage

Well Drained

Zinnia Planting Risk Windows

Early Start (70% safe) ✓ Fits season (6 days to spare)
Start indoors: Mar 15 Transplant: Apr 19 🌸 Bloom: Jun 28 – Oct 4
Recommended (50%) ✓ Fits season (9 days to spare)
Start indoors: Mar 20 Transplant: Apr 24 🌸 Bloom: Jul 3 – Oct 9
Safe Start (90%) ✓ Fits season (10 days to spare)
Start indoors: Apr 2 Transplant: May 7 🌸 Bloom: Jul 16 – Oct 22

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 Doniphan County

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

Soil pH

Your soil pH (6.8–7.3) is within Zinnia's preferred range (5.5–7.5).

Soil Texture

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

Drainage

Drainage is adequate for Zinnia.

Organic Matter

Organic matter is excellent (4.1%) — Zinnia will thrive.

How to Plant Zinnia

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

Succession Planting Zinnia

3
successive plantings in your 184-day season

Sow every 6.9 weeks. Last sowing by Aug 09 to harvest before frost.

Zinnia Water Budget

Plant needs
0.5″/week
Rainfall provides
0.6″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 80 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — 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 0.8" 0" ❄️ Dormant
Feb 0.9" 0" ❄️ Dormant
Mar 1.7" 0" ❄️ Dormant
Apr 2.2" 2.6" 0" ✅ Rainfall sufficient
May 2.2" 4" 0" ✅ Rainfall sufficient
Jun 2.2" 4.2" 0" ✅ Rainfall sufficient
Jul 2.2" 3.7" 0" ✅ Rainfall sufficient
Aug 2.2" 3.3" 0" ✅ Rainfall sufficient
Sep 2.2" 2.2" 0" ✅ Rainfall sufficient
Oct 2.2" 1.9" 0.3" 💧 Light watering
Nov 0.8" 0" ❄️ Dormant
Dec 0.6" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Doniphan 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 2,668 GDD Excellent fit

Zinnia Planting Timeline — Doniphan County, KS

Zinnia Planting Calendar

Activity When Date Range
Start Indoors March 20 Mar 20 – Apr 3
Transplant Outdoors April 24 Apr 24 – May 8
Direct Sow April 24 Apr 24 – May 15
Bloom July 3 Jul 3 – Oct 9

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
July Bloom
August Bloom
September Bloom
October Bloom
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Only during dry spells

📅 Days to Maturity

60–70 days

🧪 Soil pH

Needs 5.5–7.5 · Your soil: ideal

🗺️ USDA Zone

Zone 6a

📆 Growing Season

184 days in Doniphan County

Growing Tips for Zinnia in Doniphan County

Direct sow Zinnia outdoors after April 17 in Doniphan 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 Doniphan County, KS?

Doniphan County is in Zone 6a with an average last frost of April 17. Plan your Zinnia planting based on this frost date — see the calendar above for exact timing.

What planting zone is Doniphan County, KS?

Doniphan County, Kansas is in USDA Hardiness Zone 6a. The average last spring frost is April 17 and first fall frost is October 18.

When should I plant Zinnia in Doniphan County County, ?

In Doniphan County County, , plant Zinnia after the last frost (around April 17) and before the first frost (around October 18). Best results when soil holds above 50°F.

What growing zone is Doniphan County County, for Zinnia?

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

Can Zinnia grow in Doniphan County County's climate?

Yes — Zinnia grows well in Doniphan County County's temperate climate. Doniphan County County averages a 184-day frost-free season, with last frost around April 17 and first frost around October 18.

🌱

Your Doniphan County Garden Planner — Free

A 22-page printable planner built for Doniphan 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 Doniphan 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.