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.

The USDA zone info for Libertyville can be reviewed 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 to plant:	Up to 3 weeks before last frost.

Cosmos do ok in moderate cold which tells us that you can get them planted just a bit earlier than other plants that might not handle the cold.

The earliest that you can plant cosmos in Libertyville 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. You can get started a few weeks earlier by starting your cosmos indoors.

Last Frost Date

On average the last frost has passed is on April 15 in Libertyville. In the coldest months of winter you should expect an average low temperature of -15°F.

Since the USDA zone info for Libertyville is an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Libertyville you get surprised by a frost after April 15 be ready to cover your cosmos in the event of a late frost.

USDA Zone Info for Libertyville

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 Libertyville

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