One of the first steps you take when you are getting a good idea your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A common way of estimating when it's a good idea to plant dianthus is to examine the USDA zone info for Healdsburg.

Planting Calendar for Dianthus

Frost tolerance for dianthus:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Dianthus tend to make it in mild cold which means that you can plant them just a bit earlier in the year than other frost tender plants.

The earliest that you can plant dianthus in Healdsburg is January. However, you really should wait until February if you don't want to take any chances.

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

Last Frost Date

The average date of last frost is February 15 in Healdsburg. It might get as low as 25°F during the coldest months of winter.

Since the USDA zone info for Healdsburg is an average the actual date of last frost is different every year. Half of the time in Healdsburg there is a last frost after February 15 so be sure to be ready to cover your dianthus in the event of 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.