One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You can estimate when it's a good idea to plant tithonia in Sioux City by looking at the USDA zone info.

Planting Calendar for Tithonia

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

It's probably not a good idea to plant tithonia until after the last frost because they do not do well in cold weather.

The earliest that you can plant tithonia in Sioux 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 tithonia and expect a good harvest is probably August. If you wait any later than that and your tithonia may not have a chance to really do well. If you are starting your tithonia indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Sioux City. In the coldest months of winter you can expect an average low temperature of -20°F.

Always keep in mind 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 Sioux City and it will vary from year to year. Since half of the time in Sioux City it frosts late in the year after April 15 be ready to cover your tithonia if you have a late frost.

USDA Zone Info for Sioux 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 Sioux City

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