One of the best tools that you have as gardeners to help us determine 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.

In Healdsburg you can figure out when it's possible to plant nierembergia 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 has passed.

Nierembergia require warm weather which tells us that you must wait until it warms up after all chance of frost has passed before you can plant them.

The earliest that you can plant nierembergia in Healdsburg 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. Any later than that and your nierembergia may not have a chance to fully mature. If you are starting your nierembergia indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

The average date of last frost is February 15 in Healdsburg. In the coldest months of winter you can expect an average low temperature of 25°F.

Keep in mind that USDA zone info for Healdsburg may not be accurate from year to year and the actual date of last frost changes from year to year. Since half of the time in Healdsburg you get a frost after February 15 be ready to protect your nierembergia if you have one of those late frosts.

USDA Zone Info for Healdsburg

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 Healdsburg

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