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When to Plant Gladiolus in Clark County, NV

Clark County, Nevada Zone 9b June

What to do in June

If you only do a handful of things in the garden this June, make it these. They're sequenced around your zone's frost timing.

Avg. last frost February 28
Avg. first frost November 23
Soil temp (4") 79°F
Watering Critical
Pest pressure High
Daylight 14.5 hrs
  1. Basket week: gladiolus

    Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.

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.

Clark County, Nevada is in USDA Zone 9b. The average last spring frost is February 28 and the first fall frost is November 23, giving you a growing season of approximately 268 days.

At an elevation of 2,811 feet, Clark County receives approximately 9.3 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 111°F, so Gladiolus may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Gladiolus will need more frequent watering and organic matter to retain nutrients. With low rainfall, drip irrigation is essential for growing Gladiolus successfully. Mulch heavily to conserve soil moisture.

Bulb Blooms in Summer Pollinator-friendly Good for cutting
Clark County, NV (Zone 9b) Long season
268 days
Last Spring Frost February 28
268 growing days
First Fall Frost November 23

Clark County Soil Profile

Soil Type

Sandy Loam

Soil pH

7.3-8.4

Drainage

Well Drained

Gladiolus Planting Risk Windows

Early Start (70% safe) ✓ Fits season (7 days to spare)
Transplant: Feb 11 🌸 Bloom: Apr 22 – Nov 4
Recommended (50%) ✓ Fits season (2 days to spare)
Transplant: Feb 28 🌸 Bloom: May 9 – Nov 21
Safe Start (90%) ✗ May not fit
Transplant: Apr 5 🌸 Bloom: Jun 14 – Dec 27

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 Clark County

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

Soil pH

Your soil pH (7.3–8.4) is more alkaline than Gladiolus prefers (6.0–6.5). Add sulfur or peat moss to lower pH.

Soil Texture

Sandy soil in Clark County warms quickly in spring but drains fast. Gladiolus will need more frequent watering and regular compost additions to retain nutrients.

Drainage

Drainage is adequate for Gladiolus.

Organic Matter

Organic matter is low (0.8%). Add 2-3 inches of compost before planting Gladiolus.

How to Plant Gladiolus

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

Succession Planting Gladiolus

4
successive plantings in your 268-day season

Sow every 8 weeks. Last sowing by Aug 15 to harvest before frost.

Gladiolus Water Budget

Plant needs
1.0″/week
Rainfall provides
0.2″/week
You supply
1.4″/week
Watering frequency 2-3 times/week
Season total 3,318 gal / 100 sq ft
Drought risk

Water stress score is 10/10 — 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 0.7" 0" ❄️ Dormant
Feb 4.3" 0.6" 3.7" 🚿 Regular watering
Mar 4.3" 0.6" 3.7" 🚿 Regular watering
Apr 4.3" 0.3" 4" 🚿 Regular watering
May 4.3" 0.2" 4.1" 🚿 Regular watering
Jun 4.3" 0.3" 4" 🚿 Regular watering
Jul 4.3" 1.5" 2.8" 🚿 Regular watering
Aug 4.3" 1.9" 2.4" 🚿 Regular watering
Sep 4.3" 1.2" 3.1" 🚿 Regular watering
Oct 4.3" 0.9" 3.4" 🚿 Regular watering
Nov 4.3" 0.5" 3.8" 🚿 Regular watering
Dec 0.7" 0" ❄️ Dormant

Water needs are for active growing months only (Feb–Nov in Clark 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 ~2,826 GDD — county provides 8,944 GDD Excellent fit

Gladiolus Planting Timeline — Clark County, NV

Gladiolus Planting Calendar

Activity When Date Range
Transplant Outdoors February 28 Feb 28 – Mar 14
Direct Sow February 28 Feb 28 – Mar 21
Bloom May 9 May 9 – Nov 21

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 2-3 times/week

📅 Days to Maturity

70–100 days

🧪 Soil pH

Needs 6–6.5 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 9b

📆 Growing Season

268 days in Clark County

Growing Tips for Gladiolus in Clark County

Direct sow Gladiolus outdoors after February 28 in Clark County when soil has warmed and frost danger has passed.

Sandy soil in Clark County dries quickly — mulch Gladiolus with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

With summer highs reaching 111°F in Clark County, provide afternoon shade for Gladiolus and water deeply in the morning.

Clark County receives only 9" 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 Clark County, NV?

Clark County is in Zone 9b with an average last frost of February 28. Plan your Gladiolus planting based on this frost date — see the calendar above for exact timing.

What planting zone is Clark County, NV?

Clark County, Nevada is in USDA Hardiness Zone 9b. The average last spring frost is February 28 and first fall frost is November 23.

🌱

Your Clark County Garden Planner — Free

A 22-page printable planner built for Clark County (Zone 9b). 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 Clark County, NV. 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.