When to Plant Cosmos in Park Forest, IL

One of the best tools that you have as gardeners to help us figure out 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.

You can estimate when it's the best time to plant cosmos in Park Forest by looking at the USDA zone info.


Planting Calendar for Cosmos

Frost tolerance for cosmos: Tolerant of a very small amount of frost.
When to plant: Up to 3 weeks before last frost.

Since cosmos are barely cold tolerant you can plant them slightly earlier in the year than more sensitive plants.

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

The earliest that you can plant cosmos in Park Forest 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 cosmos and expect a good harvest is probably August. Any later than that and your cosmos may not have a chance to really do well. Starting your cosmos 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 Park Forest. In the coldest months of winter you should expect an average low temperature of -15°F.

Remember that USDA zone info for Park Forest is an average and the actual date of last frost changes from year to year. Half of the time in Park Forest you get surprised by a frost after April 15 so be sure to be ready to protect your cosmos if you have a surprise late frost.

USDA Zone Info for Park Forest

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 Park Forest

You may be interested in your other planting guides for Park Forest.