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

By using the USDA zone info for Yorkville it's possible 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.

Cosmos are one of those plants that can tolerate a tiny bit of cold weather 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 Yorkville 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. You probably don't want to wait any later than that or else your cosmos may not have a chance to fully mature. You can get started a little bit earlier by starting your cosmos indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Yorkville. In the coldest months of winter you should expect an average low temperature of -15°F.

Just be sure to remember that USDA zone info for Yorkville is an average and the actual date of last frost changes from year to year. Since half of the time in Yorkville last frost occurs after April 15 be ready to protect your cosmos in the event of a surprise late frost.

USDA Zone Info for Yorkville

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 Yorkville

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