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When to Plant Gladiolus in Arthur County, NE

Arthur County, Nebraska Zone 5b June

Your June game plan for Arthur County, Nebraska

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

Avg. last frost May 9
Avg. first frost October 6
Soil temp (4") 65°F
Watering High
Pest pressure High
Daylight 15 hrs

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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.

Arthur County, Nebraska is in USDA Zone 5b. The average last spring frost is May 9 and the first fall frost is October 6, giving you a growing season of approximately 150 days.

At an elevation of 728 feet, Arthur County receives approximately 34 inches of rainfall annually with predominantly loam soil. Summer highs average 81°F, so choose short-season varieties of Gladiolus to ensure they mature before fall.

Bulb Blooms in Summer Pollinator-friendly Good for cutting
Arthur County, NE (Zone 5b) Moderate season
150 days
Last Spring Frost May 9
150 growing days
First Fall Frost October 6
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Arthur County Soil Profile

Soil Type

Loam

Soil pH

6.2-7.7

Drainage

Well Drained

Gladiolus Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: May 9 🌸 Bloom: Aug 1 – Oct 31
Recommended (50%) ✗ May not fit
Transplant: May 16 🌸 Bloom: Aug 8 – Nov 7
Safe Start (90%) ✗ May not fit
Transplant: May 29 🌸 Bloom: Aug 21 – Nov 20

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 Arthur County

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

Soil pH

Your soil pH (6.2–7.7) is more alkaline than Gladiolus prefers (6.0–6.5). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.7%). Annual compost additions will help Gladiolus.

How to Plant Gladiolus

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

Succession Planting Gladiolus

2
successive plantings in your 150-day season

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

Gladiolus Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 77 gal / 100 sq ft
Drought risk

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

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 2.1" 0" ❄️ Dormant
Feb 2.2" 0" ❄️ Dormant
Mar 3.4" 0" ❄️ Dormant
Apr 3.6" 0" ❄️ Dormant
May 4.3" 4.3" 0" ✅ Rainfall sufficient
Jun 4.3" 2.2" 2.1" 💧 Light watering
Jul 4.3" 3.2" 1.1" 💧 Light watering
Aug 4.3" 3.2" 1.1" 💧 Light watering
Sep 4.3" 2.5" 1.8" 💧 Light watering
Oct 4.3" 3.2" 1.1" 💧 Light watering
Nov 2.6" 0" ❄️ Dormant
Dec 1.8" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Arthur 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 ~914 GDD — county provides 1,612 GDD Excellent fit

Gladiolus Planting Timeline — Arthur County, NE

Gladiolus Planting Calendar

Activity When Date Range
Transplant Outdoors May 16 May 16 – May 30
Direct Sow May 16 May 16 – Jun 6
Bloom August 8 Aug 8 – Nov 7

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

Month-by-Month Timeline

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

🗺️ USDA Zone

Zone 5b

📆 Growing Season

150 days in Arthur County

Growing Tips for Gladiolus in Arthur County

Direct sow Gladiolus outdoors after May 09 in Arthur 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 Arthur County, NE?

Arthur County is in Zone 5b with an average last frost of May 9. Plan your Gladiolus planting based on this frost date — see the calendar above for exact timing.

What planting zone is Arthur County, NE?

Arthur County, Nebraska is in USDA Hardiness Zone 5b. The average last spring frost is May 9 and first fall frost is October 6.

🌱

Your Arthur County Garden Planner — Free

A 22-page printable planner built for Arthur County (Zone 5b). 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 Arthur County, NE. 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.