When to Plant Cosmos in Addison, IL

Before planting it is a good idea to find your USDA Zone info to estimate 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.

By checking out the USDA zone info for Addison you will be able to estimate when you can plant cosmos.


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.

You can plant cosmos just a tiny bit earlier in the year because they do ok in moderate 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 Addison 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. If you wait any later than that and your cosmos may not have a chance to really do well. You can get started a few weeks earlier by starting your cosmos indoors.

Last Frost Date

In Addison the average date of last frost happens on April 15. In the coldest months of winter you should expect an average low temperature of -15°F.

Keep in mind that USDA zone info for Addison may not be accurate from year to year and the actual date of last frost will vary from year to year. Half of the time in Addison you get a frost after April 15 so just be sure to be ready to cover your cosmos in the event of a surprise late frost.

USDA Zone Info for Addison

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 Addison

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