Before planting it is a good idea to find your USDA Zone info to figure out 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 USDA zone info for Zion can be read to figure out when it's possible to 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 just a tiny bit earlier in the year than more sensitive plants.

The earliest that you can plant cosmos in Zion 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 grow to maturity. Starting your cosmos indoors is a great way to get them started a little bit earlier.

Last Frost Date

In Zion the average date of last frost happens on April 15. In the coldest months of winter you can expect an average low temperature of -15°F.

Always keep in mind that USDA zone info for Zion is an average and the actual date of last frost will vary from year to year. Since half of the time in Zion you get surprised by a frost after April 15 be ready to protect your cosmos if you have one of those late frosts.

USDA Zone Info for Zion

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 Zion

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