Blog

When to Plant Gladiolus in Coryell County, TX

Coryell County, Texas Zone 8b June

Top priorities for Coryell County, Texas gardeners in June

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

Avg. last frost March 16
Avg. first frost November 15
Soil temp (4") 72°F
Watering Low
Pest pressure High
Daylight 14 hrs
  1. Start harvesting gladiolus

    This is the payoff month. Bring a basket, bring a friend, and get into the beds.

A few tasks this June that'll pay off in July
  • First harvests: gladiolus

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.

Coryell County, Texas is in USDA Zone 8b. The average last spring frost is March 16 and the first fall frost is November 15, giving you a growing season of approximately 244 days.

At an elevation of 3,488 feet, Coryell County receives approximately 65 inches of rainfall annually with predominantly clay soil. Summer highs average 91°F, providing good warmth for Gladiolus during the growing season. Clay soil retains moisture well for Gladiolus, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Gladiolus root diseases.

Bulb Blooms in Summer Pollinator-friendly Good for cutting
Coryell County, TX (Zone 8b) Long season
244 days
Last Spring Frost March 16
244 growing days
First Fall Frost November 15

Coryell County Soil Profile

Soil Type

Clay

Soil pH

7-8.3

Drainage

Well Drained

Gladiolus Planting Risk Windows

Early Start (70% safe) ✓ Fits season (12 days to spare)
Transplant: Mar 5 🌸 Bloom: May 14 – Oct 29
Recommended (50%) ✓ Fits season (6 days to spare)
Transplant: Mar 16 🌸 Bloom: May 25 – Nov 9
Safe Start (90%) ✗ May not fit
Transplant: Apr 10 🌸 Bloom: Jun 19 – Dec 4

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 Coryell County

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

Soil pH

Your soil pH (7.0–8.3) is more alkaline than Gladiolus prefers (6.0–6.5). Add sulfur or peat moss to lower pH.

Soil Texture

Heavy clay soil (41% clay) in Coryell County compacts easily and drains slowly. Amend with compost and avoid working soil when wet.

Organic Matter

Organic matter is moderate (3.3%). 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 244-day season

Sow every 8 weeks. Last sowing by Aug 07 to harvest before frost.

Gladiolus Water Budget

Plant needs
1.0″/week
Rainfall provides
1.1″/week
Watering frequency Natural rainfall sufficient
Season total 0 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 1.8" 0" ❄️ Dormant
Feb 2.3" 0" ❄️ Dormant
Mar 4.3" 3.8" 0.5" 💧 Light watering
Apr 4.3" 6.9" 0" ✅ Rainfall sufficient
May 4.3" 9.1" 0" ✅ Rainfall sufficient
Jun 4.3" 9.5" 0" ✅ Rainfall sufficient
Jul 4.3" 9" 0" ✅ Rainfall sufficient
Aug 4.3" 7.2" 0" ✅ Rainfall sufficient
Sep 4.3" 7.1" 0" ✅ Rainfall sufficient
Oct 4.3" 4.6" 0" ✅ Rainfall sufficient
Nov 4.3" 2" 2.3" 🚿 Regular watering
Dec 1.7" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Coryell 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 ~1,551 GDD — county provides 4,453 GDD Excellent fit

Gladiolus Planting Timeline — Coryell County, TX

Gladiolus Planting Calendar

Activity When Date Range
Transplant Outdoors March 16 Mar 16 – Mar 30
Direct Sow March 16 Mar 16 – Apr 6
Bloom May 25 May 25 – Nov 9

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

Month-by-Month Timeline

MonthActivities
January
February
March Transplant Outdoors Direct Sow
April Direct Sow
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 · Natural rainfall sufficient

📅 Days to Maturity

70–100 days

🧪 Soil pH

Needs 6–6.5 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 8b

📆 Growing Season

244 days in Coryell County

Growing Tips for Gladiolus in Coryell County

Direct sow Gladiolus outdoors after March 16 in Coryell County when soil has warmed and frost danger has passed.

With Coryell County's clay soil (41% clay), work in 3-4 inches of compost before planting Gladiolus. Avoid tilling when soil is wet to prevent compaction.

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 Coryell County, TX?

Coryell County is in Zone 8b with an average last frost of March 16. Plan your Gladiolus planting based on this frost date — see the calendar above for exact timing.

What planting zone is Coryell County, TX?

Coryell County, Texas is in USDA Hardiness Zone 8b. The average last spring frost is March 16 and first fall frost is November 15.

🌱

Your Coryell County Garden Planner — Free

A 22-page printable planner built for Coryell County (Zone 8b). 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 Coryell 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.