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When to plant Gladiolus in Greene County, IN

Greene County's spring Gladiolus window runs April 15 through May 6. time plantings around the expected last-frost window for best survival.

When to Plant Gladiolus in Greene County, IN

Greene County, Indiana Zone 6b June

Your June planting checklist for Greene County, Indiana

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

Avg. last frost April 15
Avg. first frost October 21
Soil temp (4") 73°F
Watering Low
Pest pressure High
Daylight 14.7 hrs
A few tasks this June that'll pay off in July
  • First harvests: gladiolus

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Gladiolus (Gladiolus spp.) produce tall, stately spikes of trumpet-shaped blooms in a rich array of colors, making them one of the most popular cut flowers in the world. Each spike carries 12–20 florets that open in succession from bottom to top over 7–10 days. By planting corms every two weeks from last frost through early summer, gardeners create a continuous succession of fresh blooms from midsummer through fall. Corms multiply each season — a single planting becomes a growing collection over the years. Ideal for back-of- border planting, cutting gardens, and mixed summer containers.

Greene County, Indiana is in USDA Zone 6b. The average last spring frost is April 15 and the first fall frost is October 21, giving you a growing season of approximately 189 days.

At an elevation of 1,023 feet, Greene County receives approximately 39 inches of rainfall annually with predominantly silt loam soil. Summer highs average 91°F, providing good warmth for Gladiolus during the growing season.

Bulb Blooms in Summer Pollinator-friendly Good for cutting
Greene County, IN (Zone 6b) Moderate season
189 days
Last Spring Frost April 15
189 growing days
First Fall Frost October 21

Greene County Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-7.1

Drainage

Well Drained

Gladiolus Planting Risk Windows

Early Start (70% safe) ✓ Fits season (1 days to spare)
Transplant: Apr 9 🌸 Bloom: Jun 25 – Oct 15
Recommended (50%) ✓ Fits season (0 days to spare)
Transplant: Apr 15 🌸 Bloom: Jul 1 – Oct 21
Safe Start (90%) ✗ May not fit
Transplant: May 1 🌸 Bloom: Jul 17 – Nov 6

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 Greene County

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

Soil pH

Your soil pH (5.8–7.1) overlaps with Gladiolus's range (6.0–6.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.6%) — Gladiolus will thrive.

How to Plant Gladiolus

5"
Planting Depth
5"
Between Plants
12"
Between Rows

Succession Planting Gladiolus

3
successive plantings in your 189-day season

Sow every 8 weeks. Last sowing by Jul 13 to harvest before frost.

Gladiolus Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 224 gal / 100 sq ft

Monthly Watering Guide for Gladiolus

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

Month Gladiolus Needs Rainfall You Supplement Action
Jan 1.5" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 2.4" 0" ❄️ Dormant
Apr 4.3" 3.9" 0.4" 💧 Light watering
May 4.3" 4.8" 0" ✅ Rainfall sufficient
Jun 4.3" 4.6" 0" ✅ Rainfall sufficient
Jul 4.3" 4.3" 0" ✅ Rainfall sufficient
Aug 4.3" 3.8" 0.5" 💧 Light watering
Sep 4.3" 3.8" 0.5" 💧 Light watering
Oct 4.3" 3.4" 0.9" 💧 Light watering
Nov 2.6" 0" ❄️ Dormant
Dec 2.4" 0" ❄️ Dormant

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

Gladiolus 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.

Gladiolus needs ~1,551 GDD — county provides 3,449 GDD Excellent fit

Gladiolus Planting Timeline — Greene County, IN

Gladiolus Planting Calendar

Activity When Date Range
Transplant Outdoors April 15 Apr 15 – Apr 29
Direct Sow April 15 Apr 15 – May 6
Bloom July 1 Jul 1 – Oct 21

Plant 5" deep · 5" apart · Rows 12" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

70–100 days

🧪 Soil pH

Needs 6–6.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 6b

📆 Growing Season

189 days in Greene County

Growing Tips for Gladiolus in Greene County

Direct sow Gladiolus outdoors after April 15 in Greene County when soil has warmed and frost danger has passed.

General growing tips

Plant corms 4–6 inches deep, pointed end up, as soon as soil reaches 60°F after last frost. Space 4–6 inches apart; rows 12 inches apart. Stake or grow through a support grid — tall varieties reach 4–5 feet and tip in wind. Begin succession plantings every 2 weeks through early July for continuous bloom. Water deeply once a week; mulch to conserve moisture and suppress weeds. Cut spikes for vases when the lowest floret just begins to open. After first killing frost (in cold zones), dig corms, let dry for 3–4 weeks in a ventilated spot, remove cormels, and store in mesh bags at 35–50°F. In zones 7b–8a, corms sometimes survive mild winters in ground with heavy mulch; in zones 8b+, in-ground overwintering is reliable.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Gladiolus in Greene County, IN?

Greene County is in Zone 6b with an average last frost of April 15. Plan your Gladiolus planting based on this frost date — see the calendar above for exact timing.

What planting zone is Greene County, IN?

Greene County, Indiana is in USDA Hardiness Zone 6b. The average last spring frost is April 15 and first fall frost is October 21.

When should I plant Gladiolus in Greene County, IN?

In Greene County, IN, plant Gladiolus after the last frost (around April 15) and before the first frost (around October 21). Best results when soil holds above 50°F.

What growing zone is Greene County, IN for Gladiolus?

Greene County sits in USDA Zone 6b. Gladiolus grows reliably in zones 3a through 10b, so it's a good fit here.

Can Gladiolus grow in Greene County's climate?

Yes — Gladiolus grows well in Greene County's temperate climate. Greene County averages a 189-day frost-free season, with last frost around April 15 and first frost around October 21.

🌱

Your Greene County Garden Planner — Free

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

Sources & credits

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