Blog

When to plant Gladiolus in Bingham County County,

Plant Gladiolus in Bingham County County, between May 28 and June 18 — the only viable window. Zone 5b's short season (123 frost-free days) rules out a fall crop.

When to Plant Gladiolus in Bingham County, ID

Bingham County, Idaho Zone 5b June

This month in Bingham County, Idaho

We've pulled the most time-sensitive tasks for Bingham County, Idaho this June and put them front and centre. Tackle them in order.

Avg. last frost May 21
Avg. first frost September 21
Soil temp (4") 42°F
Watering High
Pest pressure High
Daylight 15.2 hrs

Instant PDF download. No spam, unsubscribe any time.

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.

Bingham County, Idaho is in USDA Zone 5b. The average last spring frost is May 21 and the first fall frost is September 21, giving you a growing season of approximately 123 days.

At an elevation of 8,345 feet, Bingham County receives approximately 24.5 inches of rainfall annually with predominantly loam soil. Summer highs average 86°F, providing good warmth for Gladiolus during the growing season.

Bulb Blooms in Summer Pollinator-friendly Good for cutting
Bingham County, ID (Zone 5b) Short season
123 days
Last Spring Frost May 21
123 growing days
First Fall Frost September 21
Share this guide:

Bingham County Soil Profile

Soil Type

Loam

Soil pH

6.3-7.7

Drainage

Well Drained

Gladiolus Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: May 17 🌸 Bloom: Aug 9 – Nov 8
Recommended (50%) ✗ May not fit
Transplant: May 28 🌸 Bloom: Aug 20 – Nov 19
Safe Start (90%) ✗ May not fit
Transplant: Jun 23 🌸 Bloom: Sep 15 – Dec 15

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 Bingham County

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

Soil pH

Your soil pH (6.3–7.7) is more alkaline than Gladiolus prefers (6.0–6.5). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.6%). Annual compost additions will help Gladiolus.

How to Plant Gladiolus

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

Gladiolus Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 215 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 1.5" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 2.1" 0" ❄️ Dormant
Apr 2.9" 0" ❄️ Dormant
May 4.3" 2.5" 1.8" 💧 Light watering
Jun 4.3" 1.5" 2.8" 🚿 Regular watering
Jul 4.3" 2.3" 2" 💧 Light watering
Aug 4.3" 2.5" 1.8" 💧 Light watering
Sep 4.3" 2.3" 2" 💧 Light watering
Oct 2.4" 0" ❄️ Dormant
Nov 1.8" 0" ❄️ Dormant
Dec 1.2" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Bingham 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 ~1,232 GDD — county provides 1,783 GDD Excellent fit

Gladiolus Planting Timeline — Bingham County, ID

Gladiolus Planting Calendar

Activity When Date Range
Transplant Outdoors May 28 May 28 – Jun 11
Direct Sow May 28 May 28 – Jun 18
Bloom August 20 Aug 20 – Nov 19

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

Month-by-Month Timeline

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

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

123 days in Bingham County

Growing Tips for Gladiolus in Bingham County

Direct sow Gladiolus outdoors after May 21 in Bingham County when soil has warmed and frost danger has passed.

Bingham County receives only 24" of rain annually. Gladiolus needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

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 Bingham County, ID?

Bingham County is in Zone 5b with an average last frost of May 21. Plan your Gladiolus planting based on this frost date — see the calendar above for exact timing.

What planting zone is Bingham County, ID?

Bingham County, Idaho is in USDA Hardiness Zone 5b. The average last spring frost is May 21 and first fall frost is September 21.

When should I plant Gladiolus in Bingham County, ?

In Bingham County, , plant Gladiolus after the last frost (around May 21) and before the first frost (around September 21). Best results when soil holds above 50°F.

What growing zone is Bingham County, for Gladiolus?

Bingham County sits in USDA Zone 5b. Gladiolus grows reliably in zones 3a through 10b, so it's a good fit here.

Can Gladiolus grow in Bingham County's climate?

Yes — Gladiolus grows well in Bingham County's temperate climate. Bingham County averages a 123-day frost-free season, with last frost around May 21 and first frost around September 21.

🌱

Your Bingham County Garden Planner — Free

A 22-page printable planner built for Bingham 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.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Bingham County, ID. 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.