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When to plant Gladiolus in Knott County, KY

Spring Gladiolus in Knott County goes in April 23–May 14, once nighttime temps stop dipping near freezing.

When to Plant Gladiolus in Knott County, KY

Knott County, Kentucky Zone 7a June

This month in Knott County, Kentucky

Each item below is timed to Knott County, Kentucky's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost April 23
Avg. first frost October 18
Soil temp (4") 68°F
Watering Moderate
Pest pressure High
Daylight 14.6 hrs
Coming up in July — start thinking about
  • 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.

Knott County, Kentucky is in USDA Zone 7a. The average last spring frost is April 23 and the first fall frost is October 18, giving you a growing season of approximately 178 days.

At an elevation of 2,201 feet, Knott County receives approximately 40.8 inches of rainfall annually with predominantly silt 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
Knott County, KY (Zone 7a) Moderate season
178 days
Last Spring Frost April 23
178 growing days
First Fall Frost October 18

Knott County Soil Profile

Soil Type

Silt Loam

Soil pH

5.4-6.8

Drainage

Well Drained

Gladiolus Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: Apr 15 🌸 Bloom: Jun 24 – Oct 28
Recommended (50%) ✗ May not fit
Transplant: Apr 23 🌸 Bloom: Jul 2 – Nov 5
Safe Start (90%) ✗ May not fit
Transplant: May 12 🌸 Bloom: Jul 21 – Nov 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 Knott County

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

Soil pH

Your soil pH (5.4–6.8) overlaps with Gladiolus's range (6.0–6.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.5%). 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 178-day season

Sow every 8 weeks. Last sowing by Jul 10 to harvest before frost.

Gladiolus Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
You supply
0.0″/week
Watering frequency Only during dry spells
Season total 59 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 3.2" 0" ❄️ Dormant
Feb 3.3" 0" ❄️ Dormant
Mar 4.2" 0" ❄️ Dormant
Apr 4.3" 3.2" 1.1" 💧 Light watering
May 4.3" 3.7" 0.6" 💧 Light watering
Jun 4.3" 3.1" 1.2" 💧 Light watering
Jul 4.3" 4.6" 0" ✅ Rainfall sufficient
Aug 4.3" 3.5" 0.8" 💧 Light watering
Sep 4.3" 3.1" 1.2" 💧 Light watering
Oct 4.3" 2.8" 1.5" 💧 Light watering
Nov 3.2" 0" ❄️ Dormant
Dec 3" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Knott 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 2,581 GDD Excellent fit

Gladiolus Planting Timeline — Knott County, KY

Gladiolus Planting Calendar

Activity When Date Range
Transplant Outdoors April 23 Apr 23 – May 7
Direct Sow April 23 Apr 23 – May 14
Bloom July 2 Jul 2 – Nov 5

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

Month-by-Month Timeline

MonthActivities
January
February
March
April Transplant Outdoors Direct Sow
May Transplant Outdoors Direct Sow
June
July Bloom
August Bloom
September Bloom
October Bloom
November Bloom
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 7a

📆 Growing Season

178 days in Knott County

Growing Tips for Gladiolus in Knott County

Direct sow Gladiolus outdoors after April 23 in Knott 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 Knott County, KY?

Knott County is in Zone 7a with an average last frost of April 23. Plan your Gladiolus planting based on this frost date — see the calendar above for exact timing.

What planting zone is Knott County, KY?

Knott County, Kentucky is in USDA Hardiness Zone 7a. The average last spring frost is April 23 and first fall frost is October 18.

When should I plant Gladiolus in Knott County, KY?

In Knott County, KY, plant Gladiolus after the last frost (around April 23) and before the first frost (around October 18). Best results when soil holds above 50°F.

What growing zone is Knott County, KY for Gladiolus?

Knott County sits in USDA Zone 7a. Gladiolus grows reliably in zones 3a through 10b, so it's a good fit here.

Can Gladiolus grow in Knott County's climate?

Yes — Gladiolus grows well in Knott County's temperate climate. Knott County averages a 178-day frost-free season, with last frost around April 23 and first frost around October 18.

🌱

Your Knott County Garden Planner — Free

A 22-page printable planner built for Knott 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 Knott County, KY. 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.