One of the first steps you take when you are getting a good idea your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You can estimate when you can plant tall phlox in South Sioux City by using the USDA zone info.

Planting Calendar for Tall Phlox

Frost tolerance for tall phlox:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

You can plant tall phlox just a bit earlier in the year because they do well in moderate cold.

The earliest that you can plant tall phlox in South Sioux City is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant tall phlox and expect a good harvest is probably September. Any later than that and your tall phlox may not have a chance to grow to maturity. Starting your tall phlox indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

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

Since the USDA zone info for South Sioux City is an average the actual date of last frost will vary from year to year. Since half of the time in South Sioux City you get a frost after April 15 be ready to cover your tall phlox if you have one of those late frosts.

USDA Zone Info for South 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 South Sioux City

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