Before planting it is a good idea to find your USDA Zone info to estimate 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 best time to plant zinnia in Charles City should be estimated by reviewing the USDA zone info.

Planting Calendar for Zinnia

Frost tolerance for zinnia:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

It's probably a bad idea to plant zinnia until after the last frost when the weather gets warmer because they require warm weather.

The earliest that you can plant zinnia in Charles City 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 grow to maturity. If you are starting your zinnia indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Charles City the average date of last frost happens on April 15. In the coldest months of winter you can expect an average low temperature of -20°F.

Just be sure to remember that the actual date of last frost is an average because it is based on the USDA zone info for Charles City and it changes from year to year. Half of the time in Charles City last frost occurs after April 15 so always be ready to protect your zinnia if you have one of those late frosts.

USDA Zone Info for Charles City

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Charles City

You may be interested in your other planting guides for Charles City.