When can I plant Gladiolus in Zone 1a

One of the first steps we take when we are getting a good idea our gardening schedule is find our USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for our area.

You will be able to estimate when to plant gladiolus by using the USDA zone info for Zone 1a.


Planting Calendar for Gladiolus

Frost tolerance for gladiolus: Tolerant of a very small amount of frost.
When you should plant them: Up to 3 weeks before last frost.

Since gladiolus are barely cold tolerant you can plant them just a tiny bit earlier in the year than other plants that might not handle the cold.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant gladiolus
Possibly ok, but a risky time to plant gladiolus
Probably not a good time to plant gladiolus

The earliest that you can plant gladiolus in Zone 1a is June. However, you really should wait until July if you don't want to take any chances.

The last month that you can plant gladiolus and expect a good harvest is probably July. If you wait any later than that and your gladiolus may not have a chance to fully mature. If you are starting your gladiolus indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Zone 1a the average date of last frost happens on June 15. We should expect an average low temperature of -60°F in the coldest months of winter.

Since the USDA zone info for Zone 1a is an average our actual date of last frost is different every year. Half of the time in Zone 1a we get a frost after June 15 so just be sure to be ready to cover your gladiolus if we have a surprise late frost.

USDA Zone Info for Zone 1a

Here is the info for USDA Zone 1a.

Average Date of Last Frost (spring)June 15
Average Date of First Frost (fall)July 15
Lowest Expected Low-60°F
Highest Expected Low-55°F

This means that on a really cold year, the coldest it will get is -60°F. On most years you should be prepared to experience lows near -55°F.

Plants to Grow in Zone 1a

You may be interested in our other planting guides for Zone 1a.