Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The earliest that you can plant zinnia in Cheyenne can be determined by using the USDA zone info.

Planting Calendar for Zinnia

Frost tolerance for zinnia:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

It's probably a bad idea to plant zinnia until after the last frost when the weather gets warmer because they do not do well in cold weather.

The earliest that you can plant zinnia in Cheyenne 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 zinnia and expect a good harvest is probably August. If you wait any later than that and your zinnia may not have a chance to really do well. If you are starting your zinnia indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

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

Keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Cheyenne and it is different every year. Half of the time in Cheyenne it frosts late in the year after April 15 so make sure that you are ready to cover your zinnia in the event of a surprise late frost.

USDA Zone Info for Cheyenne

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 Cheyenne

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