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 referring to the USDA zone info for Waseca 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.

Cosmos do well in a tiny bit of cold which tells us that you can plant them a bit earlier in the year than more sensitive plants.

The earliest that you can plant cosmos in Waseca 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 really do well. Starting your cosmos indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

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

Since the USDA zone info for Waseca is just an average the actual date of last frost is different every year. Half of the time in Waseca you get surprised by a frost after May 15 so make sure that you are ready to cover your cosmos if you have a late frost.

USDA Zone Info for Waseca

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 Waseca

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