One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A common way of getting a good idea when you can plant gladiolus is to consult the USDA zone info for Carol Stream.

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.

Gladiolus are barely cold tolerant which means that you can plant them slightly earlier than more sensitive plants.

The earliest that you can plant gladiolus in Carol Stream 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. If you wait any later than that and your gladiolus may not have a chance to really do well. If you are starting your gladiolus indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average the last frost has passed is on April 15 in Carol Stream. In the coldest months of winter you should expect an average low temperature of -15°F.

Since the USDA zone info for Carol Stream is just an average the actual date of last frost is different every year. Half of the time in Carol Stream you get surprised by a frost after April 15 so make sure that you are ready to protect your gladiolus in the event of a late frost.

USDA Zone Info for Carol Stream

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Carol Stream

You may be interested in your other planting guides for Carol Stream.