One of the first steps you take when you are estimating 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 figure out when it's possible to plant cosmos by looking at the USDA zone info for Morrison.

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 can survive in mild cold which means that you can plant them slightly earlier in the year than other frost tender plants.

The earliest that you can plant cosmos in Morrison 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. If you are starting your cosmos indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

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

Since the USDA zone info for Morrison is not always accurate the actual date of last frost changes from year to year. Half of the time in Morrison last frost occurs after April 15 so be sure to be ready to protect your cosmos in the event of a late frost.

USDA Zone Info for Morrison

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 Morrison

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