When to Plant Gladiolus in Prospect Heights, IL

Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The USDA zone info for Prospect Heights should be reffered to in order to estimate when it's possible 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.

Gladiolus are barely cold tolerant which tells us that you can get them planted just a bit earlier than plants that are more sensitive to 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 Prospect Heights 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 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 is on April 15 in Prospect Heights. It might get as low as -15°F during the coldest months of winter.

It's important to remember that USDA zone info for Prospect Heights is not always accurate and the actual date of last frost changes from year to year. Since half of the time in Prospect Heights last frost occurs after April 15 be ready to protect your gladiolus in the event of a surprise late frost.

USDA Zone Info for Prospect Heights

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 Prospect Heights

You may be interested in your other planting guides for Prospect Heights.