When to Plant Bearded Iris in Michigan
Plant Bulbs (Fall)
Saturday, August 15, 2026
State
Michigan
USDA Zones
4a, 4b, 5a, 5b, 6a, 6b, 7a
Avg Last Frost
Thursday, April 15, 2027
Cities Covered
881
Michigan Planting Schedule by Zone
Michigan spans 7 zones — find yours below for the most accurate dates.
| Zone | Last Frost | Plant (Fall) |
|---|---|---|
| 4a | Saturday, May 15, 2027 | Thursday, July 16, 2026 |
| 4b | Wednesday, May 5, 2027 | Tuesday, July 21, 2026 |
| 5a | Monday, May 10, 2027 | Sunday, July 26, 2026 |
| 5b | Sunday, April 25, 2027 | Friday, July 31, 2026 |
| 6a | Tuesday, April 20, 2027 | Thursday, August 6, 2026 |
| 6b | Thursday, April 15, 2027 | Saturday, August 15, 2026 |
| 7a | Saturday, April 10, 2027 | Thursday, August 20, 2026 |
Dates based on average last frost. Check your local forecast before planting.
🌿 About Bearded Iris
Growing Bearded Iris in Michigan: Complete Guide
Bearded Iris (Iris germanica) is fall-planted — it goes in the ground a few weeks before the first fall frost and overwinters for blooms the following spring. Depending on your zone, Michigan gardeners plant between July 16, 2026 (Zone 4a) and August 20, 2026 (Zone 7a).
Because Michigan stretches across 7 USDA hardiness zones (4a, 4b, 5a, 5b, 6a, 6b, 7a), planting windows can shift by as much as six to eight weeks from one end of the state to the other. Gardeners in the warmer southern zones can start earlier, while those in cooler northern zones should wait until the zone table above shows their last frost has passed.
With 240 days to maturity, Bearded Iris fits comfortably within Michigan's growing season in most zones. In the warmest parts of the state, a second planting later in the season may be possible.
Bearded Iris requires full sun (6+ hours) and low; avoid wet soil moisture. Midwest growing seasons are compressed between late spring frosts and fall cold snaps, so timing transplants precisely pays off.
For the most precise planting dates tailored to your exact location, enter your ZIP code on our planting calendar or use the zone table above to find the schedule for your area of Michigan.
Frequently Asked Questions
When should I plant Bearded Iris in Michigan?
In Michigan, plant Bearded Iris bulbs in fall, around Saturday, August 15, 2026, so roots establish before the ground freezes. Michigan spans zones 4a–7a, so exact timing shifts with your zone's first fall frost.
What is the last frost date in Michigan?
Michigan spans 7 USDA zones (4a, 4b, 5a, 5b, 6a, 6b, 7a), so last frost dates vary by region. Champion, Arnold, Michigamme (4a) sees frost until around Saturday, May 15, 2027, while Macatawa (7a) is frost-free much earlier.
How long does Bearded Iris take to grow in Michigan?
Bearded Iris takes about 240 days from planting to bloom. Fall planting lets roots establish over winter for spring blooms.
What USDA zones does Michigan cover for Bearded Iris?
Michigan includes zones 4a, 4b, 5a, 5b, 6a, 6b, 7a. Bearded Iris grows well across all of these zones with adjusted timing — use the zone table above to find the right dates for your part of the state.
When to Plant Bearded Iris by City in Michigan
Dates are based on each city's USDA zone and average last frost.
| City | Zone | Last Frost | Plant (Fall) |
|---|---|---|---|
| Acme | 6a | Tuesday, April 20, 2027 | Thursday, August 6, 2026 |
| Ada | 6a | Tuesday, April 20, 2027 | Thursday, August 6, 2026 |
| Addison | 6a | Tuesday, April 20, 2027 | Thursday, August 6, 2026 |
| Adrian | 6a | Tuesday, April 20, 2027 | Thursday, August 6, 2026 |
| Afton | 4b | Wednesday, May 5, 2027 | Tuesday, July 21, 2026 |
| Ahmeek | 5b | Sunday, April 25, 2027 | Friday, July 31, 2026 |
| Akron | 6a | Tuesday, April 20, 2027 | Thursday, August 6, 2026 |
| Alanson | 5a | Monday, May 10, 2027 | Sunday, July 26, 2026 |
| Alba | 5b | Sunday, April 25, 2027 | Friday, July 31, 2026 |
| Albion | 6a | Tuesday, April 20, 2027 | Thursday, August 6, 2026 |
| Alden | 5b | Sunday, April 25, 2027 | Friday, July 31, 2026 |
| Alger | 5b | Sunday, April 25, 2027 | Friday, July 31, 2026 |
| Algonac | 6b | Thursday, April 15, 2027 | Saturday, August 15, 2026 |
| Allegan | 6a | Tuesday, April 20, 2027 | Thursday, August 6, 2026 |
| Allen | 6a | Tuesday, April 20, 2027 | Thursday, August 6, 2026 |
| Allen Park | 6b | Thursday, April 15, 2027 | Saturday, August 15, 2026 |
| Allendale | 6a | Tuesday, April 20, 2027 | Thursday, August 6, 2026 |
| Allenton | 6a | Tuesday, April 20, 2027 | Thursday, August 6, 2026 |
| Allouez | 5b | Sunday, April 25, 2027 | Friday, July 31, 2026 |
| Alma | 6a | Tuesday, April 20, 2027 | Thursday, August 6, 2026 |
| Almont | 6a | Tuesday, April 20, 2027 | Thursday, August 6, 2026 |
| Alpena | 5b | Sunday, April 25, 2027 | Friday, July 31, 2026 |
| Alpha | 4b | Wednesday, May 5, 2027 | Tuesday, July 21, 2026 |
| Alto | 6a | Tuesday, April 20, 2027 | Thursday, August 6, 2026 |
| Amasa | 4a | Saturday, May 15, 2027 | Thursday, July 16, 2026 |
| Anchorville | 6b | Thursday, April 15, 2027 | Saturday, August 15, 2026 |
| Ann Arbor | 6a | Tuesday, April 20, 2027 | Thursday, August 6, 2026 |
| Applegate | 6a | Tuesday, April 20, 2027 | Thursday, August 6, 2026 |
| Arcadia | 6b | Thursday, April 15, 2027 | Saturday, August 15, 2026 |
| Argyle | 6a | Tuesday, April 20, 2027 | Thursday, August 6, 2026 |
| Armada | 6a | Tuesday, April 20, 2027 | Thursday, August 6, 2026 |
| Arnold | 4a | Saturday, May 15, 2027 | Thursday, July 16, 2026 |
| Ashley | 6a | Tuesday, April 20, 2027 | Thursday, August 6, 2026 |
| Athens | 6a | Tuesday, April 20, 2027 | Thursday, August 6, 2026 |
| Atlanta | 5a | Monday, May 10, 2027 | Sunday, July 26, 2026 |
| Atlantic Mine | 5b | Sunday, April 25, 2027 | Friday, July 31, 2026 |
| Atlas | 6a | Tuesday, April 20, 2027 | Thursday, August 6, 2026 |
| Attica | 6a | Tuesday, April 20, 2027 | Thursday, August 6, 2026 |
| Au Gres | 6a | Tuesday, April 20, 2027 | Thursday, August 6, 2026 |
| Au Train | 5b | Sunday, April 25, 2027 | Friday, July 31, 2026 |
| Auburn | 6a | Tuesday, April 20, 2027 | Thursday, August 6, 2026 |
| Auburn Hills | 6a | Tuesday, April 20, 2027 | Thursday, August 6, 2026 |
| Augusta | 6a | Tuesday, April 20, 2027 | Thursday, August 6, 2026 |
| Avoca | 6a | Tuesday, April 20, 2027 | Thursday, August 6, 2026 |
| Azalia | 6a | Tuesday, April 20, 2027 | Thursday, August 6, 2026 |
| Bad Axe | 6a | Tuesday, April 20, 2027 | Thursday, August 6, 2026 |
| Bailey | 6a | Tuesday, April 20, 2027 | Thursday, August 6, 2026 |
| Baldwin | 5b | Sunday, April 25, 2027 | Friday, July 31, 2026 |
| Bancroft | 6a | Tuesday, April 20, 2027 | Thursday, August 6, 2026 |
| Bangor | 6a | Tuesday, April 20, 2027 | Thursday, August 6, 2026 |
| Bannister | 6a | Tuesday, April 20, 2027 | Thursday, August 6, 2026 |
| Baraga | 5a | Monday, May 10, 2027 | Sunday, July 26, 2026 |
| Barbeau | 4b | Wednesday, May 5, 2027 | Tuesday, July 21, 2026 |
| Bark River | 5a | Monday, May 10, 2027 | Sunday, July 26, 2026 |
| Baroda | 6b | Thursday, April 15, 2027 | Saturday, August 15, 2026 |
| Barryton | 5b | Sunday, April 25, 2027 | Friday, July 31, 2026 |
| Barton City | 5a | Monday, May 10, 2027 | Sunday, July 26, 2026 |
| Bath | 6a | Tuesday, April 20, 2027 | Thursday, August 6, 2026 |
| Battle Creek | 6a | Tuesday, April 20, 2027 | Thursday, August 6, 2026 |
| Bay City | 6a | Tuesday, April 20, 2027 | Thursday, August 6, 2026 |
Showing 60 of 881 cities. Enter your ZIP on the planting calendar for your exact dates.