The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Mason City you can figure out when it's the best time to plant lithospermum by referring to the USDA zone info.

Planting Calendar for Lithospermum

Frost tolerance for lithospermum:	Not tolerant of frost.
When to plant:	After the last frost.

Lithospermum are not cold tolerant which means that it's important to wait until it warms up after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant lithospermum in Mason 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. Any later than that and your lithospermum may not have a chance to really do well. Starting your lithospermum indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In Mason City the average date of last frost happens on April 15. You should expect an average low temperature of -20°F in the coldest months of winter.

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 Mason City and it can change quite a bit from year to year. Since half of the time in Mason City last frost occurs after April 15 be ready to cover your lithospermum in the event of a late frost.

USDA Zone Info for Mason 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 Mason City

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