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.

A common way of determining when it's the best time to plant zinnia is to look at the USDA zone info for Carterville.

Planting Calendar for Zinnia

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

It's not a good 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 Carterville 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 grow to maturity. You can get started a little bit earlier by starting your zinnia indoors.

Last Frost Date

On average the last frost has passed is on April 15 in Carterville. In the coldest months of winter you can expect an average low temperature of -5°F.

Just be sure to remember that USDA zone info for Carterville is an average and the actual date of last frost can change quite a bit from year to year. Half of the time in Carterville you get a frost after April 15 so be sure to be ready to protect your zinnia if you have one of those late frosts.

USDA Zone Info for Carterville

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Carterville

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