Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Dubuque should be looked at to figure out when it's the best time to plant gladiolus.

Planting Calendar for Gladiolus

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

You can plant gladiolus just a tiny bit earlier in the year because they are barely cold tolerant.

The earliest that you can plant gladiolus in Dubuque is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant gladiolus and expect a good harvest is probably August. Any later than that and your gladiolus may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your gladiolus indoors.

Last Frost Date

The average date of last frost is April 15 in Dubuque. It might get as low as -20°F during the coldest months of winter.

Since the USDA zone info for Dubuque is just an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Dubuque you get a frost after April 15 be ready to cover your gladiolus in the event of a late frost.

USDA Zone Info for Dubuque

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Dubuque

You may be interested in your other planting guides for Dubuque.