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When to Plant Gladiolus in Jackson County, TX

Jackson County, Texas Zone 9b June

June to-do list for Jackson County, Texas

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

Avg. last frost February 21
Avg. first frost December 5
Soil temp (4") 87°F
Watering Low
Pest pressure High
Daylight 13.8 hrs
  1. Start harvesting gladiolus

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

July will be here before you know it — start on
  • 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.

Jackson County, Texas is in USDA Zone 9b. The average last spring frost is February 21 and the first fall frost is December 5, giving you a growing season of approximately 287 days.

At an elevation of 286 feet, Jackson County receives approximately 64.3 inches of rainfall annually with predominantly loam soil. Summer highs average 103°F, so Gladiolus may need afternoon shade and extra watering during peak heat. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Gladiolus root diseases.

Bulb Blooms in Summer Pollinator-friendly Good for cutting
Jackson County, TX (Zone 9b) Year-round
287 days
Last Spring Frost February 21
287 growing days
First Fall Frost December 5
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Jackson County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.2

Drainage

Well Drained

Gladiolus Planting Risk Windows

Early Start (70% safe) ✓ Fits season (23 days to spare)
Transplant: Feb 8 🌸 Bloom: Apr 19 – Nov 1
Recommended (50%) ✓ Fits season (21 days to spare)
Transplant: Feb 21 🌸 Bloom: May 2 – Nov 14
Safe Start (90%) ✓ Fits season (13 days to spare)
Transplant: Mar 14 🌸 Bloom: May 23 – Dec 5

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 Jackson County

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

Soil pH

Your soil pH (6.5–7.2) is more alkaline than Gladiolus prefers (6.0–6.5). Add sulfur or peat moss to lower pH.

Soil Texture

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

Drainage

Drainage is adequate for Gladiolus.

Organic Matter

Organic matter is moderate (2.0%). Annual compost additions will help Gladiolus.

How to Plant Gladiolus

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

Succession Planting Gladiolus

4
successive plantings in your 287-day season

Sow every 8 weeks. Last sowing by Aug 27 to harvest before frost.

Gladiolus Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 929 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 1.7" 0" ❄️ Dormant
Feb 4.3" 2.1" 2.2" 🚿 Regular watering
Mar 4.3" 3.9" 0.4" 💧 Light watering
Apr 4.3" 6.5" 0" ✅ Rainfall sufficient
May 4.3" 9" 0" ✅ Rainfall sufficient
Jun 4.3" 10.4" 0" ✅ Rainfall sufficient
Jul 4.3" 7.9" 0" ✅ Rainfall sufficient
Aug 4.3" 8" 0" ✅ Rainfall sufficient
Sep 4.3" 6" 0" ✅ Rainfall sufficient
Oct 4.3" 4.8" 0" ✅ Rainfall sufficient
Nov 4.3" 2.3" 2" 💧 Light watering
Dec 4.3" 1.7" 2.6" 🚿 Regular watering

Water needs are for active growing months only (Feb–Dec in Jackson 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 ~2,316 GDD — county provides 7,848 GDD Excellent fit

Gladiolus Planting Timeline — Jackson County, TX

Gladiolus Planting Calendar

Activity When Date Range
Transplant Outdoors February 21 Feb 21 – Mar 7
Direct Sow February 21 Feb 21 – Mar 14
Bloom May 2 May 2 – Nov 14

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
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

70–100 days

🧪 Soil pH

Needs 6–6.5 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 9b

📆 Growing Season

287 days in Jackson County

Growing Tips for Gladiolus in Jackson County

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

With summer highs reaching 103°F in Jackson County, provide afternoon shade for Gladiolus and water deeply in the morning.

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 Jackson County, TX?

Jackson County is in Zone 9b with an average last frost of February 21. Plan your Gladiolus planting based on this frost date — see the calendar above for exact timing.

What planting zone is Jackson County, TX?

Jackson County, Texas is in USDA Hardiness Zone 9b. The average last spring frost is February 21 and first fall frost is December 5.

🌱

Your Jackson County Garden Planner — Free

A 22-page printable planner built for Jackson 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 Jackson County, TX. 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.