The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. 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 Ionia should be read to figure out when it's the best time to 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 well in very little cold which tells us that you can plant them slightly earlier in the year than other plants that might not handle the cold.

The earliest that you can plant cosmos in Ionia 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 fully mature. You can get started a couple of weeks earlier by starting your cosmos indoors.

Last Frost Date

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

It's important to remember that the actual date of last frost is an average because it is based on the USDA zone info for Ionia and it is different every year. Half of the time in Ionia you get a frost after April 15 so make sure that you are ready to cover your cosmos if you have a surprise late frost.

USDA Zone Info for Ionia

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 Ionia

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