One of the first steps you take when you are getting a good idea 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.

You should be able to estimate when it's possible to plant cosmos by referring to the USDA zone info for Alliance.

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 slightly earlier in the year than more sensitive plants.

The earliest that you can plant cosmos in Alliance 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. You probably don't want to wait any later than that or else your cosmos may not have a chance to grow to maturity. Starting your cosmos indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost is on April 15 in Alliance. In the coldest months of winter you can expect an average low temperature of -20°F.

Keep in mind that USDA zone info for Alliance may not be accurate from year to year and the actual date of last frost can change quite a bit from year to year. Since half of the time in Alliance there is a last frost after April 15 be ready to cover your cosmos in the event of a late frost.

USDA Zone Info for Alliance

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Alliance

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