Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The first chance to plant nierembergia in Santa Rosa should be determined by checking out the USDA zone info.

Planting Calendar for Nierembergia

Frost tolerance for nierembergia:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

Nierembergia are not cold tolerant which means that it is necessary to wait until it warms up after the last frost has passed before you can plant them.

The earliest that you can plant nierembergia 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 nierembergia and expect a good harvest is probably September. If you wait any later than that and your nierembergia may not have a chance to really do well. If you are starting your nierembergia indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Santa Rosa the average date of last frost happens on February 15. In the coldest months of winter you can expect an average low temperature of 25°F.

Always keep in mind that USDA zone info for Santa Rosa is not always accurate and the actual date of last frost is different every year. Since half of the time in Santa Rosa you get surprised by a frost after February 15 be ready to protect your nierembergia if you have 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.