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

In Santa Rosa you can determine when to plant lithospermum by reviewing the USDA zone info.

Planting Calendar for Lithospermum

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

Lithospermum do not do well in cold weather which tells us that you really should wait until it warms up after all chance of frost has passed before you can plant them.

The earliest that you can plant lithospermum in Santa Rosa 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. You probably don't want to wait any later than that or else your lithospermum may not have a chance to really do well. Starting your lithospermum indoors is a great way to get them started a little bit earlier.

Last Frost Date

In Santa Rosa the average date of last frost happens on February 15. It might get as low as 25°F during the coldest months of winter.

Keep in mind that USDA zone info for Santa Rosa is an average and the actual date of last frost will vary from year to year. Half of the time in Santa Rosa it frosts late in the year after February 15 so make sure that you are ready to protect your lithospermum in the event of a surprise late frost.

USDA Zone Info for Santa Rosa

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°F

This means that on a really cold year, the coldest it will get is 25°F. On most years you should be prepared to experience lows near 30°F.

Plants to Grow in Santa Rosa

You may be interested in your other planting guides for Santa Rosa.