When to Plant Calliopsis in Mount Prospect, IL

The USDA Zone info is a great tool for gardeners to help us determine your gardening 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 Mount Prospect can be looked at to determine when it's possible to plant calliopsis.


Planting Calendar for Calliopsis

Frost tolerance for calliopsis: Not tolerant of frost.
When to plant: After the last frost.

Calliopsis are not cold tolerant which tells us that you need to wait until it warms up after the last frost before you can plant them.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant calliopsis
Possibly ok, but a risky time to plant calliopsis
Probably not a good time to plant calliopsis

The earliest that you can plant calliopsis in Mount Prospect is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant calliopsis and expect a good harvest is probably August. If you wait any later than that and your calliopsis may not have a chance to fully mature. Starting your calliopsis indoors is a great way to get them started a few weeks earlier.

Last Frost Date

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

Since the USDA zone info for Mount Prospect is an average the actual date of last frost will vary from year to year. Since half of the time in Mount Prospect it frosts late in the year after April 15 be ready to cover your calliopsis if you have a late frost.

USDA Zone Info for Mount Prospect

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 Mount Prospect

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