When to Plant Gladiolus in Glenwood, IL

One of the first steps you take when you are figuring out your gardening schedule is find your 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.

By using the USDA zone info for Glenwood you should be able to estimate when you can 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.

Since gladiolus are barely cold tolerant you can plant them slightly earlier in the year 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 Glenwood 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. You probably don't want to wait any later than that or else your gladiolus may not have a chance to grow to maturity. Starting your gladiolus indoors is a great way to get them started a little bit earlier.

Last Frost Date

The average date of last frost is April 15 in Glenwood. In the coldest months of winter you can expect an average low temperature of -15°F.

Since the USDA zone info for Glenwood may not be accurate from year to year the actual date of last frost will vary from year to year. Half of the time in Glenwood last frost occurs after April 15 so make sure that you are prepared to cover your gladiolus in the event of one of those late frosts.

USDA Zone Info for Glenwood

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 Glenwood

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