The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. 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 to plant calliopsis is to look at the USDA zone info for Dayton.

Planting Calendar for Calliopsis

Frost tolerance for calliopsis:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

It's a bad idea to plant calliopsis until after all chance of frost has passed because they are not cold tolerant.

The earliest that you can plant calliopsis in Dayton is May. However, you really should wait until June if you don't want to take any chances.

The last month that you can plant calliopsis and expect a good harvest is probably August. You probably don't want to wait any later than that or else your calliopsis may not have a chance to grow to maturity. Starting your calliopsis indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost has passed is on May 15 in Dayton. It might get as low as -25°F during the coldest months of winter.

Since the USDA zone info for Dayton may not be accurate from year to year the actual date of last frost will vary from year to year. Half of the time in Dayton there is a last frost after May 15 so make sure that you are prepared to cover your calliopsis if you have a late frost.

USDA Zone Info for Dayton

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Dayton

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