When to plant gladiolus
tender corm
The short answer
Gladiolus are planted out after the last frost. You can get a head start by starting them indoors 4 to 6 weeks before the last frost.
Zone 5: plant out from Apr 30. Zone 7: plant out from Apr 5. Zone 9: plant out from Feb 20. See every zone or your state.
When to plant gladiolus by USDA zone
Dates are worked out from each zone’s typical last frost, using the number of weeks the cited extension services give. Find your zone on the zone map. Zones 11 and above are frost-free, so timing there depends on heat and rain instead.
| Zone | Typical last frost | Start corms indoors (optional) | Plant out |
|---|---|---|---|
| Zone 3 | May 15 | Apr 3 – Apr 17 | from May 15 |
| Zone 4 | May 10 | Mar 29 – Apr 12 | from May 10 |
| Zone 5 | Apr 30 | Mar 19 – Apr 2 | from Apr 30 |
| Zone 6 | Apr 15 | Mar 4 – Mar 18 | from Apr 15 |
| Zone 7 | Apr 5 | Feb 22 – Mar 8 | from Apr 5 |
| Zone 8 | Mar 20 | Feb 6 – Feb 20 | from Mar 20 |
| Zone 9 | Feb 20 | Jan 9 – Jan 23 | from Feb 20 |
| Zone 10 | Jan 30 | Dec 19 – Jan 2 | from Jan 30 |
Rule used: plant out after the last frost; start corms indoors (optional) 4 to 6 weeks before the last frost. Plant again every two weeks for continuous bloom. Iowa State's last planting is early July.
When to plant gladiolus in your state
Same rule, applied to each state’s typical last spring frost. States marked * span very different climates, so use your own frost date for the exact day - click a state for its frost dates.
| State | Typical last frost | Start corms indoors (optional) | Plant out |
|---|---|---|---|
| Alabama | Mar 25 | Feb 11 – Feb 25 | from Mar 25 |
| Alaska * | May 17 | Apr 5 – Apr 19 | from May 17 |
| Arizona * | Mar 15 | Feb 1 – Feb 15 | from Mar 15 |
| Arkansas | Apr 3 | Feb 20 – Mar 6 | from Apr 3 |
| California * | Feb 20 | Jan 9 – Jan 23 | from Feb 20 |
| Colorado | May 5 | Mar 24 – Apr 7 | from May 5 |
| Connecticut | Apr 25 | Mar 14 – Mar 28 | from Apr 25 |
| Delaware | Apr 14 | Mar 3 – Mar 17 | from Apr 14 |
| District of Columbia | Apr 10 | Feb 27 – Mar 13 | from Apr 10 |
| Florida | Feb 12 | Jan 1 – Jan 15 | from Feb 12 |
| Georgia | Mar 25 | Feb 11 – Feb 25 | from Mar 25 |
| Idaho | May 10 | Mar 29 – Apr 12 | from May 10 |
| Illinois | Apr 20 | Mar 9 – Mar 23 | from Apr 20 |
| Indiana | Apr 24 | Mar 13 – Mar 27 | from Apr 24 |
| Iowa | Apr 25 | Mar 14 – Mar 28 | from Apr 25 |
| Kansas | Apr 15 | Mar 4 – Mar 18 | from Apr 15 |
| Kentucky | Apr 18 | Mar 7 – Mar 21 | from Apr 18 |
| Louisiana | Mar 5 | Jan 22 – Feb 5 | from Mar 5 |
| Maine | May 14 | Apr 2 – Apr 16 | from May 14 |
| Maryland | Apr 14 | Mar 3 – Mar 17 | from Apr 14 |
| Massachusetts | Apr 24 | Mar 13 – Mar 27 | from Apr 24 |
| Michigan | May 10 | Mar 29 – Apr 12 | from May 10 |
| Minnesota | May 6 | Mar 25 – Apr 8 | from May 6 |
| Mississippi | Mar 20 | Feb 6 – Feb 20 | from Mar 20 |
| Missouri | Apr 15 | Mar 4 – Mar 18 | from Apr 15 |
| Montana | May 15 | Apr 3 – Apr 17 | from May 15 |
| Nebraska | Apr 30 | Mar 19 – Apr 2 | from Apr 30 |
| Nevada * | Apr 20 | Mar 9 – Mar 23 | from Apr 20 |
| New Hampshire | May 13 | Apr 1 – Apr 15 | from May 13 |
| New Jersey | Apr 20 | Mar 9 – Mar 23 | from Apr 20 |
| New Mexico * | Apr 20 | Mar 9 – Mar 23 | from Apr 20 |
| New York * | May 1 | Mar 20 – Apr 3 | from May 1 |
| North Carolina | Apr 5 | Feb 22 – Mar 8 | from Apr 5 |
| North Dakota | May 15 | Apr 3 – Apr 17 | from May 15 |
| Ohio | Apr 25 | Mar 14 – Mar 28 | from Apr 25 |
| Oklahoma | Apr 1 | Feb 18 – Mar 4 | from Apr 1 |
| Oregon * | Apr 20 | Mar 9 – Mar 23 | from Apr 20 |
| Pennsylvania | May 1 | Mar 20 – Apr 3 | from May 1 |
| Rhode Island | Apr 25 | Mar 14 – Mar 28 | from Apr 25 |
| South Carolina | Mar 25 | Feb 11 – Feb 25 | from Mar 25 |
| South Dakota | May 10 | Mar 29 – Apr 12 | from May 10 |
| Tennessee | Apr 10 | Feb 27 – Mar 13 | from Apr 10 |
| Texas * | Mar 15 | Feb 1 – Feb 15 | from Mar 15 |
| Utah | May 5 | Mar 24 – Apr 7 | from May 5 |
| Vermont | May 14 | Apr 2 – Apr 16 | from May 14 |
| Virginia | Apr 15 | Mar 4 – Mar 18 | from Apr 15 |
| Washington * | Apr 20 | Mar 9 – Mar 23 | from Apr 20 |
| West Virginia | May 5 | Mar 24 – Apr 7 | from May 5 |
| Wisconsin | May 10 | Mar 29 – Apr 12 | from May 10 |
| Wyoming | May 20 | Apr 8 – Apr 22 | from May 20 |
What extension services say
- Corms can be started indoors 4 to 6 weeks before the average last frost date for earlier bloom, planted 1-2 inches deep in a warm 70-75°F place. Iowa State University Extension ↗
- Plant outdoors after the danger of frost is past (about mid-May in central Iowa). Iowa State University Extension ↗
- Make successive plantings every two weeks for bloom all summer; the final planting is made in early July. Iowa State University Extension ↗
- Gladioli typically bloom about 8 to 10 weeks after planting. Iowa State University Extension ↗
Questions gardeners ask
When do you plant gladiolus?
After the last frost, then again every two weeks for continuous bloom. Iowa State's final planting is in early July.
How long do gladiolus take to bloom?
About 8 to 10 weeks after planting.
Sources
- Iowa State University Extension: Planting and Caring for Tender Perennials
Extension advice is local to the state that wrote it. Where the sources differ, both are shown. Dates in the tables are estimates from typical frost dates; your garden’s own last frost can differ by a week or more. How we source data.