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.

It's possible to estimate when you can plant zinnia by reviewing the USDA zone info for Chattanooga.

Planting Calendar for Zinnia

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

You can not 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 Chattanooga 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 fully mature. Starting your zinnia indoors is a great way to get them started a little bit earlier.

Last Frost Date

In Chattanooga the average date of last frost happens on April 15. In the coldest months of winter you should expect an average low temperature of 5°F.

Just be sure to remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Chattanooga and it can change quite a bit from year to year. Half of the time in Chattanooga last frost occurs after April 15 so make sure that you are prepared to cover your zinnia if you have a surprise late frost.

USDA Zone Info for Chattanooga

Here is the info for USDA Zone 7b.

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

Plants to Grow in Chattanooga

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