When to plant Gladiolus in Keweenaw County, MI
Plant Gladiolus in Keweenaw County, between May 26 and June 16 — the only viable window. Zone 5b's short season (135 frost-free days) rules out a fall crop.
When to Plant Gladiolus in Keweenaw County, MI
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.
Keweenaw County, Michigan is in USDA Zone 5b. The average last spring frost is May 19 and the first fall frost is October 1, giving you a growing season of approximately 135 days.
At an elevation of 1,035 feet, Keweenaw County receives approximately 40.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 81°F, so choose short-season varieties of Gladiolus to ensure they mature before fall.
Keweenaw County Soil Profile
Soil Type
Silt Loam
Soil pH
6.0-7.0
Drainage
Well Drained
Gladiolus Planting Timeline — Keweenaw County, MI
Gladiolus Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | May 26 | May 26 – Jun 9 |
| Direct Sow | May 26 | May 26 – Jun 16 |
| Bloom | August 18 | Aug 18 – Nov 17 |
Plant 5" deep · 5" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | Transplant Outdoors Direct Sow |
| June | Transplant Outdoors Direct Sow |
| July | — |
| August | Bloom |
| September | Bloom |
| October | Bloom |
| November | Bloom |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
Moderate — regular watering
📅 Days to Maturity
70–100 days
🧪 Soil pH
Needs 6–6.5 · Your soil: N/A
🗺️ USDA Zone
Zone 5b
📆 Growing Season
135 days in Keweenaw County
Growing Tips for Keweenaw County
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 Keweenaw County, MI?
Keweenaw County is in Zone 5b with an average last frost of May 19. Plan your Gladiolus planting based on this frost date — see the calendar above for exact timing.
What planting zone is Keweenaw County, MI?
Keweenaw County, Michigan is in USDA Hardiness Zone 5b. The average last spring frost is May 19 and first fall frost is October 1.
When should I plant Gladiolus in Keweenaw County, MI?
In Keweenaw County, MI, plant Gladiolus after the last frost (around May 19) and before the first frost (around October 1). Best results when soil holds above 50°F.
What growing zone is Keweenaw County, MI for Gladiolus?
Keweenaw County sits in USDA Zone 5b. Gladiolus grows reliably in zones 3a through 10b, so it's a good fit here.
Can Gladiolus grow in Keweenaw County's climate?
Yes — Gladiolus grows well in Keweenaw County's temperate climate. Keweenaw County averages a 135-day frost-free season, with last frost around May 19 and first frost around October 1.
Your Keweenaw County Garden Planner — Free
A 22-page printable planner built for Keweenaw County (Zone 5b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.