When can I plant Cosmos in Evanston, IL

One of the first steps we take when we are figuring out our gardening schedule is find our USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for our area.

The USDA zone info for Evanston should be looked at to figure out when you can plant cosmos.


Planting Calendar for Cosmos

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

Cosmos do ok in very little cold which means that 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 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 Evanston 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 fully mature. 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 Evanston. In the coldest months of winter we can expect an average low temperature of -15°F.

Remember that our actual date of last frost is not always accurate because it is based on the USDA zone info for Evanston and it changes from year to year. Half of the time in Evanston there is a last frost after April 15 so always be ready to cover your cosmos in the event of a late frost.

USDA Zone Info for Evanston

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 Evanston

You may be interested in our other planting guides for Evanston.