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

You will be able to determine when you can plant gladiolus by reviewing the USDA zone info for Herrin.

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 do ok in some cold which tells us that you can plant them a bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant gladiolus in Herrin 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 fully mature. Starting your gladiolus indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Herrin. It might get as low as -5°F during the coldest months of winter.

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

USDA Zone Info for Herrin

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Herrin

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