The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

One way of determining when it's possible to plant lithospermum is to refer to the USDA zone info for Rosenberg.

Planting Calendar for Lithospermum

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

Since lithospermum are not cold tolerant you have to wait until after the last frost has passed before you can plant them.

The earliest that you can plant lithospermum in Rosenberg is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant lithospermum and expect a good harvest is probably September. Any later than that and your lithospermum may not have a chance to really do well. You can get started a couple of weeks earlier by starting your lithospermum indoors.

Last Frost Date

The average date of last frost is February 15 in Rosenberg. In the coldest months of winter you should expect an average low temperature of 20°F.

Since the USDA zone info for Rosenberg is just an average the actual date of last frost is different every year. Half of the time in Rosenberg you get a frost after February 15 so make sure that you are ready to cover your lithospermum in the event of one of those late frosts.

USDA Zone Info for Rosenberg

Here is the info for USDA Zone 9a.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	20°F
Highest Expected Low	25°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 25°F.

Plants to Grow in Rosenberg

You may be interested in your other planting guides for Rosenberg.