When to plant Gladiolus in Cole County, MO
Aim to plant Gladiolus in Cole County on or after April 7; the window stays open through April 28. Cole County's 204-day frost-free season gives you enough for a full main crop and a short fall succession.
When to Plant Gladiolus in Cole County, MO
This month in Cole County, Missouri
Welcome to July in Zone 6b. These are the moves that will have the biggest impact on your growing season.
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It's harvest week for gladiolus
This is the payoff month. Bring a basket, bring a friend, and get into the beds.
A few tasks this July that'll pay off in August
- First harvests: gladiolus
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.
Cole County, Missouri is in USDA Zone 6b. The average last spring frost is April 7 and the first fall frost is October 28, giving you a growing season of approximately 204 days.
At an elevation of 614 feet, Cole County receives approximately 39.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88°F, providing good warmth for Gladiolus during the growing season.
Cole County Soil Profile
Soil Type
Silt Loam
Soil pH
5.4-6.9
Drainage
Well Drained
Gladiolus Planting Risk Windows
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 Cole County
How your county's soil matches Gladiolus's growing requirements.
Soil pH
Your soil pH (5.4–6.9) overlaps with Gladiolus's range (6.0–6.5), though not a perfect match.
Soil Texture
The silt loam soil in Cole 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 (3.1%). Annual compost additions will help Gladiolus.
How to Plant Gladiolus
Succession Planting Gladiolus
Sow every 8 weeks. Last sowing by Jul 20 to harvest before frost.
Gladiolus Water Budget
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 | — | 1.6" | 0" | ❄️ Dormant |
| Feb | — | 1.5" | 0" | ❄️ Dormant |
| Mar | — | 2.4" | 0" | ❄️ Dormant |
| Apr | 4.3" | 4.4" | 0" | ✅ Rainfall sufficient |
| May | 4.3" | 4.6" | 0" | ✅ Rainfall sufficient |
| Jun | 4.3" | 5.5" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 4.2" | 0.1" | 💧 Light watering |
| Aug | 4.3" | 4.1" | 0.2" | 💧 Light watering |
| Sep | 4.3" | 3.6" | 0.7" | 💧 Light watering |
| Oct | 4.3" | 2.8" | 1.5" | 💧 Light watering |
| Nov | — | 2.6" | 0" | ❄️ Dormant |
| Dec | — | 1.9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Cole 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 Planting Timeline — Cole County, MO
Gladiolus Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | April 7 | Apr 7 – Apr 21 |
| Direct Sow | April 7 | Apr 7 – Apr 28 |
| Bloom | June 23 | Jun 23 – Oct 13 |
Plant 5" deep · 5" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Transplant Outdoors Direct Sow |
| May | — |
| June | Bloom |
| July | Bloom |
| August | Bloom |
| September | Bloom |
| October | Bloom |
| November | — |
| 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: acceptable
🗺️ USDA Zone
Zone 6b
📆 Growing Season
204 days in Cole County
Growing Tips for Gladiolus in Cole County
Direct sow Gladiolus outdoors after April 07 in Cole 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 →
Gladiolus in Other Locations
Frequently Asked Questions
When should I plant Gladiolus in Cole County, MO?
Cole County is in Zone 6b with an average last frost of April 7. Plan your Gladiolus planting based on this frost date — see the calendar above for exact timing.
What planting zone is Cole County, MO?
Cole County, Missouri is in USDA Hardiness Zone 6b. The average last spring frost is April 7 and first fall frost is October 28.
When should I plant Gladiolus in Cole County, MO?
In Cole County, MO, plant Gladiolus after the last frost (around April 7) and before the first frost (around October 28). Best results when soil holds above 50°F.
What growing zone is Cole County, MO for Gladiolus?
Cole County sits in USDA Zone 6b. Gladiolus grows reliably in zones 3a through 10b, so it's a good fit here.
Can Gladiolus grow in Cole County's climate?
Yes — Gladiolus grows well in Cole County's temperate climate. Cole County averages a 204-day frost-free season, with last frost around April 7 and first frost around October 28.
Your Cole County Garden Planner — Free
A 22-page printable planner built for Cole County (Zone 6b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.