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When to plant Zinnia in Sumner County County,

Aim to plant Zinnia in Sumner County County on or after April 11; the window stays open through May 2. Sumner County County's 198-day frost-free season gives you enough for a full main crop and a short fall succession.

When to Plant Zinnia in Sumner County, KS

Sumner County, Kansas Zone 7a June

Your June planting checklist for Sumner County, Kansas

Your Sumner County, Kansas garden is entering a new phase. Here's what's on the schedule for June and why each task matters now.

Avg. last frost April 11
Avg. first frost October 26
Soil temp (4") 72°F
Watering Low
Pest pressure High
Daylight 14.5 hrs
  1. Pick zinnia

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

July prep starts now
  • 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.

Sumner County, Kansas is in USDA Zone 7a. The average last spring frost is April 11 and the first fall frost is October 26, giving you a growing season of approximately 198 days.

At an elevation of 637 feet, Sumner County receives approximately 29 inches of rainfall annually with predominantly loam soil. Summer highs average 85°F, providing good warmth for Zinnia during the growing season.

Annual Blooms in Summer Pollinator-friendly Deer-resistant Good for cutting
Sumner County, KS (Zone 7a) Moderate season
198 days
Last Spring Frost April 11
198 growing days
First Fall Frost October 26

Sumner County Soil Profile

Soil Type

Loam

Soil pH

6.4-7.8

Drainage

Well Drained

Zinnia Planting Risk Windows

Early Start (70% safe) ✓ Fits season (17 days to spare)
Start indoors: Mar 8 Transplant: Apr 5 🌸 Bloom: Jun 14 – Oct 4
Recommended (50%) ✓ Fits season (16 days to spare)
Start indoors: Mar 14 Transplant: Apr 11 🌸 Bloom: Jun 20 – Oct 10
Safe Start (90%) ✓ Fits season (19 days to spare)
Start indoors: Mar 28 Transplant: Apr 25 🌸 Bloom: Jul 4 – Oct 24

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 Sumner County

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

Soil pH

Your soil pH (6.4–7.8) overlaps with Zinnia's range (5.5–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.6%). 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 198-day season

Sow every 6.9 weeks. Last sowing by Aug 17 to harvest before frost.

Zinnia Water Budget

Plant needs
0.5″/week
Rainfall provides
0.6″/week
Watering frequency Natural rainfall sufficient
Season total 0 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 0.7" 0" ❄️ Dormant
Feb 1.1" 0" ❄️ Dormant
Mar 1.7" 0" ❄️ Dormant
Apr 2.2" 3" 0" ✅ Rainfall sufficient
May 2.2" 4.4" 0" ✅ Rainfall sufficient
Jun 2.2" 4.2" 0" ✅ Rainfall sufficient
Jul 2.2" 3.4" 0" ✅ Rainfall sufficient
Aug 2.2" 4" 0" ✅ Rainfall sufficient
Sep 2.2" 3" 0" ✅ Rainfall sufficient
Oct 2.2" 1.7" 0.5" 💧 Light watering
Nov 1.1" 0" ❄️ Dormant
Dec 0.7" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Sumner 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 ~894 GDD — county provides 2,722 GDD Excellent fit

Zinnia Planting Timeline — Sumner County, KS

Zinnia Planting Calendar

Activity When Date Range
Start Indoors March 14 Mar 14 – Mar 28
Transplant Outdoors April 11 Apr 11 – Apr 25
Direct Sow April 11 Apr 11 – May 2
Bloom June 20 Jun 20 – Oct 10

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

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Transplant Outdoors Direct Sow
May 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 7a

📆 Growing Season

198 days in Sumner County

Growing Tips for Zinnia in Sumner County

Direct sow Zinnia outdoors after April 11 in Sumner 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 Sumner County, KS?

Sumner County is in Zone 7a with an average last frost of April 11. Plan your Zinnia planting based on this frost date — see the calendar above for exact timing.

What planting zone is Sumner County, KS?

Sumner County, Kansas is in USDA Hardiness Zone 7a. The average last spring frost is April 11 and first fall frost is October 26.

When should I plant Zinnia in Sumner County County, ?

In Sumner County County, , plant Zinnia after the last frost (around April 11) and before the first frost (around October 26). Best results when soil holds above 50°F.

What growing zone is Sumner County County, for Zinnia?

Sumner County County sits in USDA Zone 7a. Zinnia grows reliably in zones 3a through 11b, so it's a good fit here.

Can Zinnia grow in Sumner County County's climate?

Yes — Zinnia grows well in Sumner County County's temperate climate. Sumner County County averages a 198-day frost-free season, with last frost around April 11 and first frost around October 26.

🌱

Your Sumner County Garden Planner — Free

A 22-page printable planner built for Sumner 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 Sumner 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.