When to Plant Cosmos in Alma, MI

One of the first steps you take when you are determining your gardening schedule is find your 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.

A common way of figuring out when it's possible to plant cosmos is to refer to the USDA zone info for Alma.


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.

You can plant cosmos slightly earlier in the year because they are one of those plants that can tolerate a tiny bit of cold weather.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant cosmos
Possibly ok, but a risky time to plant cosmos
Probably not a good time to plant cosmos

The earliest that you can plant cosmos in Alma 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 really do well. Starting your cosmos indoors is a great way to get them started a little bit earlier.

Last Frost Date

The average date of last frost is April 15 in Alma. You should expect an average low temperature of -10°F in the coldest months of winter.

Just be sure to remember that the actual date of last frost is an average because it is based on the USDA zone info for Alma and it can change quite a bit from year to year. Since half of the time in Alma you get a frost after April 15 be ready to cover your cosmos in the event of one of those late frosts.

USDA Zone Info for Alma

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)April 15
Average Date of First Frost (fall)October 15
Lowest Expected Low-10°F
Highest Expected Low-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Alma

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