Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Glen Carbon can be reffered to in order to determine when it's the best time to plant zinnia.

Planting Calendar for Zinnia

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

Zinnia do not do well in cold weather which tells us that it's important to wait until it warms up after all chance of frost has passed before you can plant them.

The earliest that you can plant zinnia in Glen Carbon 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. Any later than that and your zinnia may not have a chance to fully mature. Starting your zinnia indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Glen Carbon. In the coldest months of winter you should expect an average low temperature of -10°F.

Since the USDA zone info for Glen Carbon is an average the actual date of last frost is different every year. Half of the time in Glen Carbon it frosts late in the year after April 15 so just be sure to be ready to cover your zinnia if you have a surprise late frost.

USDA Zone Info for Glen Carbon

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Glen Carbon

You may be interested in your other planting guides for Glen Carbon.