One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By referring to the USDA zone info for South Sioux City it's possible to figure out when it's the best time to plant lithospermum.

Planting Calendar for Lithospermum

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

You really shouldn't plant lithospermum 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 lithospermum in South 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 lithospermum and expect a good harvest is probably August. If you wait any later than that and your lithospermum may not have a chance to grow to maturity. You can get started a few weeks earlier by starting your lithospermum indoors.

Last Frost Date

The average date of last frost is April 15 in South Sioux City. In the coldest months of winter you can expect an average low temperature of -20°F.

Since the USDA zone info for South Sioux City is not always accurate the actual date of last frost changes from year to year. Half of the time in South Sioux City there is a last frost after April 15 so make sure that you are ready to cover your lithospermum if you have a surprise late frost.

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.