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

You should be able to determine when to plant cosmos by checking out the USDA zone info for Minneapolis.

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.

Since cosmos are barely cold tolerant you can plant them just a tiny bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant cosmos in Minneapolis is April. However, you really should wait until May 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. If you are starting your cosmos indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

The average date of last frost is May 15 in Minneapolis. In the coldest months of winter you can expect an average low temperature of -25°F.

Remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Minneapolis and it can change quite a bit from year to year. Since half of the time in Minneapolis it frosts late in the year after May 15 be ready to cover your cosmos in the event of one of those late frosts.

USDA Zone Info for Minneapolis

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Minneapolis

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